Most cited article - PubMed ID 20131938
End-organ damage in hypertensive transgenic Ren-2 rats: influence of early and late endothelin receptor blockade
Sex-related cardiovascular differences were observed in humans as well as in experimental animals. Our previous study demonstrated a marked sexual dimorphism in blood pressure (BP) of 9-month-old heterozygous transgenic Ren 2 rats (TGR), in which mouse Ren-2 renin gene was inserted into the genome of normotensive Hannover Sprague-Dawley rats (HanSD). We found significantly elevated BP only in male TGR, whereas BP of TGR females was similar to that of HanSD females. The aim of our present study was to compare BP of 3- and 6-month-old heterozygous TGR with age- and sex-matched HanSD under the same conditions as we measured in 9-month-old rats. We also monitored the amount of oxidative stress marker, thiobarbituric acid-reactive substances (TBARS), and a main intracellular antioxidant, reduced glutathione in the heart, kidneys and liver. We also measured plasma triglycerides and cholesterol levels. We found an increased mean arterial pressure in both female and male 3-month-old TGR (172±17 vs. 187±4 mm Hg, respectively) compared to HanSD (115±5 vs. 133±3 mm Hg, respectively) but there was a marked sexual dimorphism of 6 month-old TGR where only males were hypertensive (145±5 mm Hg) while females became normotensive (123±7 mm Hg). We did not find any relationship between BP values and concentrations of TBARS or glutathione or plasma lipid levels. Our results demonstrated that 6-month-old TGR exhibited a marked sexual BP dimorphism, which was not dependent on the abnormalities in oxidative stress or cholesterol metabolism.
- MeSH
- Cholesterol MeSH
- Glutathione MeSH
- Hypertension * MeSH
- Blood Pressure MeSH
- Rats MeSH
- Thiobarbituric Acid Reactive Substances MeSH
- Kidney MeSH
- Rats, Sprague-Dawley MeSH
- Rats, Transgenic MeSH
- Renin * genetics MeSH
- Sex Factors MeSH
- Free Radicals MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Cholesterol MeSH
- Glutathione MeSH
- Thiobarbituric Acid Reactive Substances MeSH
- Renin * MeSH
- Free Radicals MeSH
Sex-related differences were observed not only in human but also in experimental hypertension. The aim of our study was to compare blood pressure (BP) of aged male and female heterozygous transgenic rats (TGR) harboring Ren-2 mouse gene, with their normotensive Hannover Sprague-Dawley (HanSD) controls. At the age of 9 months, systolic (SBP) and diastolic blood pressure (DBP) were measured by a direct puncture of carotid artery in rats awaking from isoflurane anesthesia. Thiobarbituric acid-reactive species (TBARS) formation was monitored as indicator of lipid peroxidation damage in heart, kidney and liver, whereas intracellular content of reduced glutathione was determined in the same organs as the main intracellular antioxidant. Furthermore, plasma triglycerides and total cholesterol as well as high-density lipoprotein (HDL) and low-density lipoprotein (LDL) fractions of cholesterol were measured. As compared to HanSD rats, we found significantly elevated BP only in male TGR (MAP: 123±1 vs. 171±5, SBP: 150±2 vs. 208±7, and DBP: 99±3 vs. 140±4 mm Hg), but not between TGR and HanSD females, which were both normotensive. We also did not find any significant differences in TBARS and reduced glutathione in the three above mentioned organs as well as in plasma cholesterol or its HDL and LDL fractions between transgene-negative HanSD and TGR animals of either sex. However, we found significant sex differences in TBARS, glutathione and plasma lipids in both rat strains. Our results confirmed that aged TGR exhibit a marked sexual BP dimorphism, which does not seem to be dependent on oxidative stress or abnormal cholesterol metabolism.
- MeSH
- Blood Pressure physiology MeSH
- Rats MeSH
- Mice MeSH
- Oxidative Stress physiology MeSH
- Sex Characteristics * MeSH
- Rats, Sprague-Dawley MeSH
- Rats, Transgenic MeSH
- Renin genetics metabolism MeSH
- Aging genetics metabolism MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Ren2 protein, mouse MeSH Browser
- Renin MeSH
The aim of the present study was to evaluate the hypothesis that the antihypertensive effects of inhibition of soluble epoxide hydrolase (sEH) are mediated by increased intrarenal availability of epoxyeicosatrienoic acids (EETs), with consequent improvement in renal haemodynamic autoregulatory efficiency and the pressure-natriuresis relationship. Ren-2 transgenic rats (TGR), a model of angiotensin (Ang) II-dependent hypertension, and normotensive transgene-negative Hannover Sprague-Dawley (HanSD) rats were treated with the sEH inhibitor cis-4-(4-(3-adamantan-1-yl-ureido)cyclohexyloxy)benzoic acid (c-AUCB; 26 mg/L) for 48 h. Then, the effects on blood pressure (BP), autoregulation of renal blood flow (RBF) and glomerular filtration rate (GFR), and on the pressure-natriuresis relationship in response to stepwise reductions in renal arterial pressure (RAP) were determined. Treatment with c-AUCB did not significantly change BP, renal autoregulation or pressure-natriuresis in normotensive HanSD rats. In contrast, c-AUCB treatment significantly reduced BP, increased intrarenal bioavailability of EETs and significantly suppressed AngII levels in TGR. However, treatment with c-AUCB did not significantly improve the autoregulatory efficiency of RBF and GFR in response to reductions of RAP and to restore the blunted pressure-natriuresis relationship in TGR. Together, the data indicate that the antihypertensive actions of sEH inhibition in TGR are predominantly mediated via significant suppression of intrarenal renin-angiotensin system activity.
- MeSH
- Antihypertensive Agents pharmacology MeSH
- Benzoates pharmacology MeSH
- Down-Regulation drug effects MeSH
- Epoxide Hydrolases antagonists & inhibitors MeSH
- Glomerular Filtration Rate drug effects MeSH
- Hypertension physiopathology MeSH
- Blood Pressure drug effects MeSH
- Rats MeSH
- Kidney drug effects metabolism MeSH
- Urea analogs & derivatives pharmacology MeSH
- Rats, Sprague-Dawley MeSH
- Rats, Transgenic MeSH
- Renal Circulation drug effects MeSH
- Renin-Angiotensin System drug effects MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
- Names of Substances
- 4-(4-(3-adamantan-1-ylureido)cyclohexyloxy)benzoic acid MeSH Browser
- Antihypertensive Agents MeSH
- Benzoates MeSH
- Epoxide Hydrolases MeSH
- Urea MeSH