OBJECTIVE

Retinal ganglion cell apoptosis in glaucoma is associated with elevated levels of endothelin-1 (ET1), a potent vasoconstrictor. ET1-induced retinal ischemia leads to altered expression of nitric oxide synthase (NOS) isoforms leading to increased formation of nitric oxide (NO) and retinal nitrosative stress. Since magnesium (Mg) is known to improve endothelial functions and reduce oxidative stress and taurine (TAU) possesses potent antioxidant properties, we investigated the protective effects of magnesium acetyltaurate (MgAT) against ET1-induced nitrosative stress and retinal damage in rats. We also compared the effects of MgAT with that of TAU alone.

METHODS

Sprague Dawley rats were intravitreally injected with ET1. MgAT and TAU were administered as pre-, co-, or posttreatment. Subsequently, the expression of NOS isoforms was detected in retina by immunohistochemistry, retinal nitrotyrosine level was estimated using ELISA, and retinal cell apoptosis was detected by TUNEL staining.

RESULTS

Intravitreal ET1 caused a significant increase in the expressions of nNOS and iNOS while eNOS expression was significantly reduced compared to vehicle treated group. Administration of both MgAT and TAU restored the altered levels of NOS isoform expression, reduced retinal nitrosative stress and retinal cell apoptosis. The effect of MgAT, however, was greater than that of TAU alone.

CONCLUSIONS

MgAT and TAU prevent ET1-induced retinal cell apoptosis by reducing retinal nitrosative stress in Sprague Dawley rats. Addition of TAU to Mg seems to enhance the efficacy of TAU compared to when given alone. Moreover, the pretreatment with MgAT/TAU showed higher efficacy compared to co- or posttreatment.

Increasing epidemiological studies have confirmed the association between maternal preeclampsia and elevated blood pressure in their offspring. Though case-control or cohort studies have demonstrated long-term outcomes for the offspring of preeclampsia, it is still a question that how these changes were caused by genetic reasons or by preeclampsia itself.

In our study, we explored the potential epigenetic regulation of delta-like homolog 1-maternally expressed gene 3 (DLK1-MEG3) region in human umbilical vein endothelial cells (HUVECs), and its connection with endothelium-derived factors.

We recruited 58 singletons born with spontaneous conception (control group) and 67 singletons whose mother with preeclampsia (preeclampsia group), and detected the infants' blood pressure and growth development index. To explore the potential mechanism, we did real-time PCR to test DLK1-MEG3 imprinted genes and endothelium-derived factors. ELISA confirmed the protein secretion changes between two groups. In addition to confirm epigenetic alteration in preeclampsia HUVEC, we performed pyro-sequencing to detect methylation status of two different methylation regions: intergenic differential methylation region (IG-DMR) and MEG3 DMR which control the expression of DLK1 and MEG3. Furthermore, Person correlation was used to make sure the association of methylation alteration of IG-DMR and endothelium-derived factors.

In our study, we found that DBP was significantly lower in preeclampsia offspring who born over 34 weeks compared with normal offspring (53.59 ± 1.38 vs. 59.9 ± 1.40 mmHg, P < 0.01), which leads to higher pulse pressure difference. Quantitative real-time PCR showed that imprinted gene DLK1 level significantly increased and MEG3 level decreased in HUVEC of preeclampsia group compared with control group, accompanying with lower expression of endothelial nitric oxide synthase and vascular endothelial growth factor (VEGF), higher expression of endothelin-1 (ET1), which are close related with vascular endothelial function. Meanwhile, ELISA assay of ET1, nitrite, VEGF were consistent with real-time results. Furthermore, abnormal expression of DLK1-MEG3 expression was caused by hypermethylation status of IG-DMR, And methylation status of IG-DMR highly correlated with ET1 concentration and nitrate concentration, these might be one of the mechanisms for impaired endothelial function (coefficient = 0.5806, P = 0.0115; coefficient = -0.4883, P = 0.0398).

Our results demonstrated that altered expression of imprinted genes DLK1 and MEG3 were caused by hypermethylation of IG-DMR in HUVEC of preeclampsia group, accompanied by lower secretion of nitrite, VEGF, and higher secretion of ET1. It might be one potential mechanism for higher risk of cardiovascular disease in preeclampsia offspring later in life.

OBJECTIVE

Development of a 'miniprimer' PCR assay for genotyping Pantoea stewartii subsp. stewartii, the causal agent of the Stewart's bacterial wilt on maize.

RESULTS

Four 10-nucleotide (10-nt) 'miniprimer' sets were designed and evaluated in the presence of Titanium Taq DNA polymerase. Under optimal reaction conditions, the miniprimer pair Uni-BacF-10/Uni-BacR-10 reproducibly generated identical banding patterns among 10 strains of P. stewartii subsp. stewartii, different patterns from strains of P. stewartii subsp. indologenes, other Panteoa species, Clavibacter michiganensis, Pectobacterium spp., Pseudomonas spp. and other bacterial species. The amplicons of Pantoea stewartii subsp. stewartii were cloned and sequenced to identify genes or DNA fragments that are targeted by the miniprimer PCR assay. Of the 14 'clone types' identified, sequences of a 1.23-kb fragment had a 99.8% similarity to part of the Pantoea stewartii zeaxanthin diglucoside biosynthetic operon (AY166713). Other dominant cloned fragments included a 411-bp amplicon that exhibited 99.8% similarity to the psaU gene (syn:ysaU; GQ249669), a type III protein-secretion system complex of P. stewartii subsp. stewartii strain DC283, and a 548-bp fragment showed 63% homology to the Asp/Glu racemase encoding gene in Erwinia tasmaniensis strain ET1/99.

CONCLUSIONS

The miniprimer PCR assay reported here is highly discriminatory and reproducible in genotyping Pantoea stewartii subsp. stewartii.

CONCLUSIONS

This miniprimer PCR assay could be a new reliable and rapid tool for fingerprinting the Stewart's wilt pathogen of maize.

A number of heterocycles bearing an arylpiperazinylalkyl side chain and structurally related to the previously described lead ET1 (4-amino-6-methyl-2-[3-(4-p-tolylpiperazin-1-yl)propyl]-5-vinylpyridazin-3(2H)-one) was synthesized and tested for their antinociceptive activity in Writhing Test. Many compounds, tested at doses of 20-40 mg/kg po were able to reduce the number of abdominal constrictions by more than 47% and, in same cases, the potency is comparable to lead ET1 as for 5e, 24a, 27b and 27c. The analgesia induced by the active compounds was completely prevented by pretreatment with α2-antagonist yohimbine, confirming the involvement of the adrenergic system in the mechanism of action for these new compounds.

The objective was to study the effects of endothelin-1 (ET1) on corneal wound healing after photorefractive keratectomy (PRK) in rabbit corneas. Following PRK, 18 New Zealand white rabbits were treated with ET1 in the right eyes and with phosphate-buffered salt solution (PBS) in the left eyes. Corneal epithelial wound size, corneal haze and corneal thickness were recorded. Corneal extracellular matrixes, including collagen types 3, 4 and 7, chondroitin sulfate and fibronectin, were investigated using immunohistochemistry study. ET1 increased the rate of healing of corneal epithelial wounds in rabbits. Anti-fibronectin fluorescence was present at week 12 and week 24 in ET1-treated eyes but not in the control eyes. There were no significant differences in corneal haze, corneal thickness and changes in other extracellular matrixes between ET1- and PBS-treated eyes. ET1 can enhance the deposition of fibronectin in corneal stroma and promote corneal epithelial wound healing after PRK. The increase in fibronectin probably explains the increased healing rate of corneal epithelial wounds.

Luteal development is regulated by many locally produced mediators, e.g., prostaglandins and angiogenic factors. However, the role and function of vasoactive factors in the canine corpus luteum (CL) remain largely unknown. Consequently, expression of the endothelin (ET) receptors-A and -B (ETA and ETB, revealing vasoconstriction and vasodilator properties respectively), the ET-converting enzyme (ECE1) and ET1, -2 and -3 were investigated in CL from non-pregnant dogs (days 5, 15, 25, 35, 45 and 65 post-ovulation), and at selected stages of pregnancy (pre-implantation, post-implantation, mid-gestation), and during normal and antigestagen-induced prepartum luteolysis/abortion. The interrelationship between PGE2 and the ET system was investigated in PGE2-treated canine primary lutein cells from early CL. ET1 did not change significantly over time; ET2, ECE1 and ETB were elevated in early CL and were downregulated towards the mid/late-luteal phase. The prepartum increase of ET2 was significant. ET3 increased gradually, and was highest in late CL and/or at prepartum luteolysis. ETA remained constant until the late CL phase and increased only during prepartum luteolysis. ET1 was localized to the luteal cells, and ET2, ET3 and ETA to vascular endothelium. ECE1 and ETB were detected at both locations. Except for upregulated ET1 and lack of effect on ET2, antigestagen applied to mid-pregnant dogs evoked similar changes to those observed during normal luteolysis. PGE2 upregulated ETB in treated cells; ETA and ET1 remained unaffected, and ET2 decreased. A modulatory role of the ETs in canine CL, possibly in association with other factors (e.g., PGE2 and progesterone receptor), is strongly indicated.

The endothelins (ET1, ET2, ET3) are a family of peptides that exert vasoactive and mitogenic effects. ETs bind to at least two subtypes of receptors: the ETA subtype is ET1 selective whereas the ETB subtype binds ET1, ET2 and ET3. By RT-PCR, we detected ETA receptor mRNA and ETB receptor mRNA in leiomyoma and in homologous myometrium distal from the tumor. Despite the presence of four spliced variants of ETA receptors, we identified a single class of ETA-binding sites. The level of ETB receptor mRNA was found to be higher in myometrium versus leiomyomas. Using complementary pharmacologic approach, we demonstrated the predominance of ETA receptors in normal myometrium (75% of total receptors). Both ETA and ETB transcripts coexist in leiomyomas, but we have reported only ETA binding sites. Because of growth properties of ET1, we suggest a role for this peptide in the tumoral development of human uterine smooth muscle.

The modulating effect of peroxisome proliferator-activated receptor α ligand on haemodynamic effects of phenylepherine (PE), angiotensin II (AII), endothelin 1 (ET1), acetylcholine (Ach), sodium nitroprusside (SNP) and isoproterenol (ISO) were evaluated in glycerol-induced acute kidney injury in rats. The effect of PE on fenofibrate-treated animals was a dose-dependent increase in mean arterial blood pressure (MAP). For AII and ET1, MAP was also increased for the fenofibrate group but not in a dose-dependent fashion. On the medullary blood flow (MBF), while the lower doses of PE and AII increased the perfusion unit on the fenofibrate-treated group, the higher doses decreased the perfusion unit. The ET1 increased the perfusion unit on this group but not in dose-dependent fashion. The effects of PE and AII on the cortical blood flow (CBF) of fenofibrate-treated group is similar to that of MBF for the same group but not for ET1. The effect of Ach, SNP and ISO in all the groups was the decrease in MAP. ISO caused dose-dependent increase in MBF of fenofibrate-treated group. The effect of Ach, SNP and ISO on the CBF perfusion unit was that of the increase for the fenofibrate-treated group. The study showed that fenofibrate did not attenuate increased blood pressure induced by PE, AII and ET1 but caused enhanced vasodilation by Ach, SNP and ISO.

The purpose of this study was to elucidate the mechanism of endothelin 1 (ET1) production in the cochlea of rats. Animals were anesthetized with pentobarbital sodium intraperitoneally and sacrificed by cardiac perfusion with warm saline followed by periodate-lysine-paraformaldehyde. The temporal bones and kidneys were fixed overnight in the same fixative, decalcified with 5% EDTA and embedded in paraffin. Immunohistochemical staining was performed using the labeled streptavidin biotin method to detect the localization of big endothelin 1 (BET1), ET1 and endothelin-converting enzyme 1 (ECE1). Immunoreactivity for BET1, ET1 and ECE1 was localized to the small vessels of the bony labyrinth adjacent to the spiral ligament. Immunohistochemistry for ET1 and BET1 was also localized to the spiral ligament. These results suggest that ET1 may be produced in the small vessels of the bony labyrinth adjacent to the spiral ligament and may play an important role in the cochlear function.

PIO, a synthetic ligand for PPARγ, is used clinically to treat T2DM. However, little is known about its protective effects on endothelium and the underlying mechanisms. In this study, we sought to investigate the protective effects of PIO on endothelium and its probable mechanisms: 95% confluent wild type (WT) HUVECs and PPARγLow-HUVECs that we first injured with HG (33 mmol·L-1) were first pretreated with 10 μmol·L-1 of GW9662 for 30 min, and then treated the cells with different concentrations of PIO (5, 10, or 20 μmol·L-1) for 24 h. Finally, we measured the levels of NO, ET1, TNFα, and IL6 in the cell culture supernatant. These cells were then used to determine cell viability, caspase3 activity, the levels of IKKα/β mRNA, IKKα/β, and NFκB-p65. Severe dysfunction and activation of IKKα/β-NFκB signaling occurred after we exposed HUVECs to HG. Conversely, treatment with PIO significantly attenuated the dysfunction and the activation of IKKα/β-NFκB signaling induced by HG in a dose-dependent manner. Moreover, the protective effects of PIO were completely abrogated by GW9662 or down-regulation of PPARγ. Taken together, the results indicate that PIO protects HUVECs against the HG-induced dysfunction through the inhibition of IKKα/β-NFκB signaling mediated by PPARγ.

Fluorescence correlation spectroscopy and the newly synthesized Alexa532-ET1 were used to study the dynamics of the endothelin ET(A) receptor-ligand complex alone and under the influence of a semisynthetic selective antagonist and a fungal extract on living A10 cells. Dose-dependent increase of inositol phosphate production was seen for Alexa532-ET1, and its binding was reduced to 8% by the selective endothelin ET(A) antagonist BQ-123, confirming the specific binding of Alexa532-ET1 to the endothelin ET(A) receptor. Two different lateral mobilities of the receptor-ligand complexes within the cell membrane were found allowing the discrimination of different states for this complex. BQ-123 showed a strong binding affinity to the "inactive" receptor state characterized by the slow diffusion time constant. A similar effect was observed for the fungal extract, which completely displaced Alexa532-ET1 from its binding to the "inactive" receptor state. These findings suggest that both BQ-123 and the fungal extract act as inverse agonists.

Mitomycin C treatment of Erwinia tasmaniensis strains from Australia induced prophages and the expression of bacteriocins. The bacteriocin named tasmancin inhibited E. tasmaniensis strains from South Africa and Germany. A gene cluster with a klebicin-related operon and an immunity protein was detected on plasmid pET46 from E. tasmaniensis strain <em>Et1</em>/99. PCR reactions using primers directed to this region produced signals for several strains originating from Australia, but not for strains isolated in South Africa and Germany. The latter isolates lacked plasmid pET46. Bacteriophages were induced from E. tasmaniensis strains Et88 and <em>Et1</em>4/99, both isolates from South-Eastern Australia. These phages formed plaques on several other strains from this region, as well as on E. tasmaniensis strains from South Africa and Germany. Sequencing revealed similarity of phages ϕEt88 and ϕ<em>Et1</em>4, which shared the host range on E. tasmaniensis strains. Bacteriophages and tasmancin may interfere with the viability of several related E. tasmaniensis strains in the environment of carrier strains.

Obesity represents one of serious risk factors in chronic renal failure patients (CRF). In three years prospective double-blind randomised multicentre study we monitored 66 patients with advanced chronic renal insufficiency, GFR 24.4-37.3 ml/min (0.41 to 0.62 ml/s) and BMI>> or = 30 kg/m2 on long term low-protein diet (0.6 P/kg BW/day) and ACEI + ARB. Thirty four randomly selected patients (group I) were treated with keto amino acids, 32 patients in control group (group II) with placebo. During the study period significant decrease of BMI, proteinuria and slowing in progression of renal failure (C(in)) were found. Significant changes were also noted in parameters of albumin and transferrin (p < 0.02), leucin and WQ (p < 0.01 - p < 0.02), glycaemia and HbA1c (p < 0.02), triglycerides (p < 0.01), leptin and ObRe (p < 0.01) and selected parameters of endothelial dysfunction (ET1, p < 0.02, TGFbeta1, p < 0.02). Significantly also decreased PTH value (p < 0.01). Successful treatment of obesity can significantly improve long term prognosis in CRF patients.

The potential barrier effect of erythrocytes (RBC) on renal excretion (mainly by tubular secretion) of hydrochlorothiazide (HCTZ) was evaluated in nine anesthetized rats during steady-state iv infusion. Drug concentrations in plasma and blood from the carotid artery and renal vein were assayed by a simple modified HPLC method. Renal extraction ratios were concentration-independent with a mean of 0.17 +/- 0.05 (SD). The renal excretion was found to occur primarily from the drug in plasma; the mean net fractional removal from plasma was 0.57 +/- 0.12, while that from RBC was less than 0.008 +/- 0.041. The virtual total unavailability of HCTZ from RBC (containing approximately 70% of drug in arterial blood) for renal excretion is attributed to relatively slow efflux of drug from RBC to plasma during each passage through the kidney compared with the blood transit time (in seconds). Preliminary in vitro influx and efflux kinetics of HCTZ across RBC membranes were studied using rat and human blood. The flux data could be adequately described by a linear, reversible, closed two-component system model, and the mean equilibration half-times (ET1/2) in rat and human blood were 10.9 and 20.5 min, respectively. The mean residence time of drug in blood circulation of rats was estimated to be 8.32 +/- 1.06 min, which is shorter than the ET1/2. This is consistent with data indicating that distribution equilibrium of HCTZ in arterial blood might not be reached in vivo even at steady state. Other implications of slow transport kinetics of drugs across RBC membranes are discussed.

BACKGROUND

The cementation of ceramic veneers using light-polymerized resin cement is largely dependent on the proper light activation of the cement. Light activation using high irradiance could shorten the time required to lute multiple restorations.

OBJECTIVE

The purpose of this in vitro study was to evaluate the light transmission of dental light-polymerizing units through ceramic cylinders and its effect on the polymerization kinetics of a resin cement.

METHODS

Ceramic ingots (IPS Empress Esthetic, shade ET1) were sectioned to produce cylinders 0.5, 1.0, and 2.0 mm thick. Two light-emitting diode units were evaluated: SmartLite Focus and Valo Cordless, the latter used in either Standard or Xtra Power (XP) modes. Light transmission (average of irradiance, total energy, and light-emission profile) through the cylinders was measured (n=3). The polymerization kinetics of a resin cement light polymerized through the ceramic was monitored for 5 minutes (n=3). The degree of conversion was measured again after 72 hours. Data were individually analyzed with 2-way ANOVA and the Tukey HSD test (α=.05).

RESULTS

Valo at XP presented the highest values of irradiance and SmartLite the lowest, irrespective of the ceramic thickness. Regarding the total energy, XP showed the lowest values. The total energy and irradiance lessened with the increase in ceramic thickness. In general, except for Valo at XP, the ceramic thickness did not affect the degree of conversion. Valo at XP and interposing 2.0 mm ceramic resulted in the lowest values of Rpmax.

CONCLUSIONS

The reduction of total energy and irradiance by ceramic interposition had only a slight effect on polymerization kinetics.

To test the hypothesis that intensive endurance training increases CHO utilisation during hard-intensity exercise, seven competitive road cyclists (Cy) performed three 50-min steady-state exercise tests on a cycle ergometer above their ventilatory threshold (+ 15 %) over the course of a cycling season (January [ET1], May [ET2] and September [ET3]). We compared the data with the baseline values of seven sedentary controls (Sed). CHO oxidation in Cy was higher in ET2 and ET3 than in ET1 (p < 0.05), was lower in ET3 than in ET2 (p < 0.05) and was higher in Cy than in Sed only in ET2 (p < 0.05). Lactate kinematics were lower in Cy than in Sed in all conditions (p < 0.05), but in Cy they were lower in ET2 than in ET1 and higher in ET3 than in ET2 (p < 0.05). Race performance was impaired and the overtraining score was increased at ET3 in comparison with ET2 (p < 0.05). We conclude that competitive cyclists increase CHO oxidation during hard-intensity exercise over the course of a season, but show a decline by the end of the season in association with the appearance of an overtraining state. Thus, well-trained cyclists develop a CHO dependence, which is modified with training status.

Hypertension is one of the main factors causing cardiovascular diseases. The present study was designed to evaluate the protective effect of vanillic acid against nitric oxide deficient rats. Hypertension was induced in adult male albino rats of Wistar strain, weighing 180-220g, by oral administration of N(ω)-nitro-l arginine methyl ester (l-NAME) 40mg/kg in drinking water for 4 weeks. Vanillic acid was administered orally at a dose of 50mg/kg b.w. Nitric oxide deficient rats showed increased levels of mean arterial pressure (MAP), heart rate (HR) and decreased heart nitric oxide metabolites (NOx). A significant increase in the levels of plasma cholesterol, low density lipoprotein-cholesterol (LDL-C), very low density lipoprotein-cholesterol (VLDL-C), triglycerides (TG), free fatty acids (FFA), phospholipids (PL), 3-hydroxy 3-methylglutaryl coenzyme A (HMG-CoA) reductase in the plasma, liver and kidney and decreased level of high density lipoprotein-cholesterol (HDL-C) are observed, whereas there is a decrease in the activities of plasma lipoprotein lipase (LPL) and lecithin cholesterol acyl transferase (LCAT) in nitric oxide deficient rats. l-NAME rats also showed an increase in TC, TG, FFA and PL levels in the liver and kidney tissues. Vanillic acid treatment brought the above parameters towards near normal level. Moreover the down regulated endothelial nitric oxide synthase (eNOS) and up regulated expression of endothelin 1 (ET1) components was also attenuated by vanillic acid treatment. All the above outcomes were confirmed by the histopathological examination. These results suggest that vanillic acid has enough potential to attenuate hypertension, dyslipidemia and hepatic and renal damage in nitric oxide deficient rats.

BACKGROUND

Endothelin-1 (ET1) is a potent vasoconstrictor peptide with pro-mitogenic and pro-inflammatory properties and is therefore of interest in the development of endothelial dysfunction, endothelium-dependent flow-related remodeling, and hypertension-related remodeling. ET1 can be formed through cleavage of big ET1 by endothelin-converting enzyme (ECE) and neutral endopeptidase (NEP).

METHODS

We investigated whether the dual NEP/ECE inhibitor SOL1 improves resistance artery function and structure in 12 weeks old spontaneously hypertensive rats (SHRs) and whether arterial structural responses to decreased (-90%) or increased (+100%) blood flow are impaired in young SHRs. To this end two groups of SHRs received chronic 4-week treatment at two different time points (4-8 and 8-12 weeks) prior to the experiment. We compared in-vitro effects of cyclo-oxygenase inhibition (1 μmol/l indomethacine), nitric oxide synthase inhibition (100 μmol/l N(ω)-L-nitro arginine methyl ester), and stimulation of the endothelium by 0.001-10 μmol/l acetylcholine (ACh) in isolated third-order mesenteric arteries of SHRs and aged-matched Wistar-Kyoto (WKY) rats.

RESULTS

SOL1 had no effect on blood pressure in SHRs or WKY rats. ACh caused biphasic effects in mesenteric arteries of SHRs. The contractile component (endothelium-derived contractile factor) was absent in WKY and abolished by acute indomethacin administration or chronic SOL1 treatment. Endothelium-derived nitric oxide-type responses did not differ in both strains and were not influenced by SOL1 treatment. Endothelium-derived hyperpolarizing factor-type responses were severely impaired in SHRs as compared to WKY rats and were normalized by chronic SOL1 treatment. In first-order mesenteric arteries, outward flow-induced remodeling was impaired in SHRs. Chronic SOL1 treatment did not restore this response.

CONCLUSIONS

Thus chronic SOL1 treatment during the development of hypertension in SHRs has no effect on blood pressure but improves several aspects of endothelium-dependent vasomotor responses but not arterial remodeling.

Ligand activation of peroxisome proliferator-activated receptors (PPARs) prevents cardiac myocyte hypertrophy, and we previously reported that diacylglycerol kinase zeta (DGKζ) is critically involved. DGKζ is an intracellular lipid kinase that catalyzes phosphorylation of diacylglycerol; by attenuating DAG signaling, DGKζ suppresses protein kinase C (PKC) and G-protein signaling. Here, we investigated how PPAR-DGKζ signaling blocks activation of the hypertrophic gene program. We focused on export of histone deacetylase 5 (HDAC5) from the nucleus, a key event during hypertrophy, since crosstalk occurs between PPARs and other members of the HDAC family. Using cardiac myocytes isolated from Sprague-Dawley rats, we determined that liganded PPARs disrupt endothelin-1 (ET1)-induced nuclear export of HDAC5 in a manner that is dependent on DGKζ. When DGKζ-mediated PKC inhibition was circumvented using a constitutively-active PKCε mutant, PPARs failed to block ET1-induced nuclear retention of HDAC5. Liganded PPARs also prevented (i) activation of protein kinase D (the downstream effector of PKC), (ii) HDAC5 phosphorylation at 14-3-3 protein chaperone binding sites (serines 259 and 498), and (iii) physical interaction between HDAC5 and 14-3-3, all of which are consistent with blockade of nucleo-cytoplasmic shuttling of HDAC5. Finally, the ability of PPARs to prevent neutralization of HDAC5 activity was associated with transcriptional repression of hypertrophic genes. This occurred by first, reduced MEF2 transcriptional activity and second, augmented deacetylation of histone H3 associated with hypertrophic genes expressing brain natriuretic peptide, β-myosin heavy chain, skeletal muscle α-actin, and cardiac muscle α-actin. Our findings identify spatial regulation of HDAC5 as a target for liganded PPARs, and to our knowledge, are the first to describe a mechanistic role for nuclear DGKζ in cardiac myocytes. In conclusion, these results implicate modulation of HDAC5 as a mechanism by which liganded PPARs suppress the hypertrophic gene program.

OBJECTIVE

Donor brain death produces functional and morphological changes in peripheral organs. We examined the influence of brain death on liver function.

METHODS

Fifty rats were randomly divided into three groups: controls (C), sham-operated (E1), and brain-dead (E2). All rats underwent tracheotomy with assisted respiration. The sera of rats at 1 and 3 hours after brain death were tested for the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), hyaluronic acid (HA), and endothelin-1 (ET-1). At the end of assisted respiration, liver samples were collected for ultrastructural observation.

RESULTS

At 1 and 3 hours, the levels of ALT, AST, HA, and ET-1 in group E2 were significantly higher than those in groups C and E1 (P < .05). The levels of ALT, AST, HA, and ET1 at 3 hours were significantly higher than those at 1 hour (P < .05). Under the electronic microscope, Kupffer cells were activated, sinusoidal endothelial cells (SEC) denuded, fenestration widened, and hepatocytes under the SEC exposed in group E2. In group C and E1, Kupffer cells were not obviously activated and SEC were almost intact.

CONCLUSIONS

Brain death damages hepatocytes and nonparenchymal cells in rat. Endothelin-1 and Kupffer cells play an important role in the process. The clearance of hyaluronic acid may provide reliable index to judge SEC function after brain death.

We have confirmed that renal cortical blood flow (RCBF) is significantly decreased by recombinant human erythropoietin (EPO). Endothelin-1 (ET(1)) is thought to be a mediator because its level increased significantly when EPO was administered. The present study was performed to clarify the effect of a selective ET-A receptor antagonist, S-0139, on EPO-induced RCBF reduction. Ten-week-old male Wistar rats, weighing about 250 g, were divided into five groups. Group 1 (n = 5), a control group, received normal saline solution (NSS). Group 2 (n = 5) received 200 U/kg body weight (BW) per hour of EPO. Group 3 (n = 5) received 400 U/kg BW per hour of EPO. Group 4 (n = 5) received both 200 U/kg BW per hour of EPO and 4 mg/kg BW per hour of S-0139. Group 5 (n = 5) received both 200 U/kg BW per hour of EPO and 40 mg/kg BW per hour of S-0139. Drugs were administered intravenously via the right femoral vein using a microinfusion pump for 4 h under urethane anesthesia. The RCBF was measured every 30 min by the hydrogen gas clearance method. When the 4 h had elapsed, the concentrations of plasma creatinine (Cr), ET1 and renin activity (RA) were measured. Compared with group 1, groups 2 and 3 showed significant (P < 0.001) decreases of RCBF, while the ET1 levels of these two groups increased significantly (P < 0.03). The ET1 of groups 4 and 5 also increased significantly (P < 0.03), however, the RCBF of these two groups did not decrease. No significant differences were observed in either Cr or RA between the five groups. EPO induces ET(1) secretion. The reduction of RCBF is due to ET(1)-derived vasoconstriction. S-0139 has potential for preventing EPO-induced and ET(1)-mediated RCBF reduction.

Many peptides are responsible for the coordination of muscle contraction, secretion and ciliary beating of the oviduct epithelium to allow the transport of gametes and embryos, including vascular endothelial growth factors (VEGF), prostaglandins (PGs), endotelin-1 (ET-1) and angiotensin II (Ang II). The effect of reproductive biotechnologies used to improve embryo yield on oviduct gene expression is poorly understood. Thus, the aim of the present study was to evaluate the effect of ovarian superstimulation on the mRNA expression of the genes encoding the major peptides involved in oviduct contraction in bovine. Therefore, Nelore cows were submitted to P-36 (n=5) or P-36/eCG (n=5) ovarian superstimulatory protocols and a control group of cows was not submitted to any superstimulatory protocol (n=5). The relative expression of VEGF (VEGF, Flk1, Flt1), Ang II (AGTR2, ACE1), ET1 (ET1, ECE1) and PG pathway members (PGES, EP2, EP4, COX1, COX2) was analyzed using real time RT-PCR in each of oviduct segment (infundibulum, ampulla and isthmus). All target genes were expressed in the three segments of the bovine oviduct; however, specific genes were regulated by ovarian superstimulation: EP2 and EP4 receptors mRNA was affected by P-36/eCG protocol, in the ampulla and infundibulum, respectively; and AGTR2 mRNA was up-regulated by both the P-36/eCG and P-36 protocols in the isthmus. The upregulation of EP2, EP4 and AGTR2 expression in the superstimulated cows suggests a suitable effect of FSH and eCG on bovine oviduct physiology, coordinating the contraction in Nelore cows.

OBJECTIVE

To observe the effect of electroacupuncture (EA) stimulation on the expressions of angiotensinogen (AGT), angiotensin II type 1 receptor (AT1R), endothelin-1 (ET1), and endothelin A receptor (ETAR) mRNA in spontaneously hypertensive rat (SHR) aorta.

METHODS

Eighteen male SHRs were randomly divided into three groups, an SHR group, an SHR Baihui (DU 20) and Zusanli (ST 36) acupoint (SHR-AP) group, and an SHR non-acupoint (SHR-NAP) group, with 6 rats in each group. Six Wistar rats were used as a control. Rats in the SHR-AP group were stimulated by DU 20 and ST 36 acupoints, both of which were connected with EA. EA was handled one time every Monday, Wednesday and Friday, for total 24 times (8 weeks). SHRNAP rats were acupointed at a 15°angle flat into 0.5 cm to two points, which were 1 and 2 cm from rail tip separately. EA parameters were the same as the SHR-AP rats. SHR control rats and Wistar rats were fixed without EA. Real-time quantitative polymerase chain reaction (PCR) was used to measure AGT, AT1R, ET1, and ETAR mRNA expression in rat aorta.

RESULTS

EA stimulation significantly reduced rat aorta vascular AGT, ET1, ETAR and AT1R mRNA expressions in the SHR-AP and SHR-NAP groups (P <0.01). Among these four genes, AT1R mRNA expression was significantly lower in the SHR-AP than in the SHR-NAP group (P <0.01).

CONCLUSIONS

EA could reduce the AT1R mRNA expression in SHR-AP rat aorta, indicating a potential mechanism for the hypotensive effects of EA.

The present study investigated the effects of cyanidin 3-O-glucoside (C3G) in cardiomyocytes (CM) and fibroblasts exposed to endothelin 1 (ET1), as well as in the spontaneously hypertensive rat (SHR) model, alone or in combination with hydrochlorothiazide (HCT). Adult rat CM and cardiac fibroblasts (CF) were pretreated with C3G and co-incubated with ET1 (10-7 M) for 24 hours. Five-week-old male SHR and their normotensive controls, Wistar-Kyoto rats (WKY), received one of 4 treatments via oral gavage daily for 15 weeks: (1) water (control); (2) C3G (10 mg per kg per day); (3) HCT (10 mg per kg per day); (4) C3G + HCT (10 mg per kg per day each). Blood pressure (BP) was measured at 1, 8 and 15 weeks. Echocardiography measurements were performed at 15 weeks. C3G prevented ET1-induced CM death and hypertrophy. Stimulating CF with ET1 did not induce their phenoconversion; nevertheless, C3G inhibited un-stimulated CF differentiation. HCT slowed the rise of systolic BP (SBP) in the SHR over time (week 1: SHRs control = 161 ± 6.3 mmHg, SHRs HCT = 129 ± 6.3 mmHg; week 15: SHRs control = 201 ± 7.3 mmHg, SHRs HCT = 168 ± 7.3 mmHg), but C3G had no effect on SBP (week 1: SHRs control = 161 ± 6.3 mmHg, SHRs C3G = 126 ± 6.3 mmHg; week 15: SHRs control = 201 ± 7.3 mmHg, SHRs C3G = 186 ± 7.3 mmHg). SHRs treated with C3G, HCT, and C3G + HCT had lower left ventricular mass and shorter isovolumetric relaxation time compared to control SHRs. C3G ameliorated cardiac hypertrophy and diastolic dysfunction in SHRs.