Endothelial dysfunction in cold-induced hypertensive rats.
Endothelial dysfunction can be observed in preatherosclerotic conditions. However, its pathogenetic role in hypertension is still controversial. Endothelial-dependent changes of blood pressure (BP) and expression of endothelial nitric oxide synthase (eNOS) were evaluated in cold-induced hypertensive rats. Wistar rats were exposed to cold stress for 8 weeks. Exposure to cold stress significantly increased the systolic BP in rats. The infusion of acetylcholine significantly lowered mean arterial BP in control rats by 48 +/- 2% and by 32 +/- 1% in cold-induced hypertensive rats. The acetylcholine-induced reduction of mean arterial BP was significantly attenuated in cold-induced hypertensive rats (control rats, 45 +/- 2 mm Hg; cold-induced hypertensive rats, 34 +/- 3 mm Hg; P < .05). Administration of N(G)-nitro-L-arginine-methyl ester for 1 week significantly increased BP in control rats, whereas no effect could be observed in cold-induced hypertensive rats. In cold-induced hypertensive rats eNOS in aortic vessels was significantly reduced compared to control rats. In this nongenetic, nonsurgical animal model of cold-induced hypertensive rats an endothelial dysfunction can be observed due to reduced eNOS.
Zhu
Zhiming
Z
Department of Hypertension and Endocrinology, Daping Hospital, Third Military Medical University, Chongqing, PR China. zhuzm@cta.cq.cn
Zhu
Shanjun
S
Zhu
Jijun
J
van der Giet
Markus
M
Tepel
Martin
M
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000503:physiopathology; D001794:Blood Pressure / Q000187:drug effects; D003080:Cold Temperature; D004730:Endothelium, Vascular / Q000503:physiopathology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006339:Heart Rate; D006973:Hypertension / Q000209:etiology* / Q000503:physiopathology*; D066298:In Vitro Techniques; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III; D051381:Rats; D017208:Rats, Wistar; D014665:Vasodilator Agents / Q000494:pharmacology
D004791:Enzyme Inhibitors; D014665:Vasodilator Agents; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D000109:Acetylcholine; D019331:NG-Nitroarginine Methyl Ester