Effect of cholecalciferol treatment on the relaxant responses of spontaneously hypertensive rat arteries to acetylcholine

Effect of cholecalciferol treatment on the relaxant responses of spontaneously hypertensive rat arteries to acetylcholine

Author Borges, Antonio Carlos Romao Autor UNIFESP Google Scholar
Feres, Teresa Autor UNIFESP Google Scholar
Vianna, L. M. Google Scholar
Paiva, Therezinha Bandiera Autor UNIFESP Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Abstract We studied the effect of oral cholecalciferol treatment on the endothelium-dependent vascular relaxation and hyperpolarization induced by acetylcholine (ACh), which is impaired in spontaneously hypertensive rats (SHR). Adult female SHR and normotensive Wistar-Kyoto rat (WKY) controls received 125 mu g of cholecalciferol per kilogram body weight per day for 6 weeks. The responses to ACh of the isolated mesenteric vascular bed and mesenteric artery rings were measured, as well as the smooth muscle cell membrane potential. After cholecalciferol treatment, the systolic blood pressure and basal perfusion pressure of the mesenteric vascular bed of the SHR fell to control levels. The relaxant and hyperpolarizing effects of ACh, which are reduced in SHR, were also brought to control levels after cholecalciferol treatment. These effects of ACh were inhibited by N-omega-nitro-L-arginine in SHR and by apamin in WKY. After cholecalciferol treatment, SHR hyperpolarizing responses showed the same inhibition pattern as those of WKY. This indicates that, after cholecalciferol treatment, SHR vascular mesenteric preparation responses to ACh are mediated by endothelium-derived hyperpolarizing factor, which induces activation of Ca2+-dependent K+ channels, as in WKY. In untreated SHR, the ACh-mediated response is entirely due to ACh acting via the release of nitric oxide.
Keywords rats, inbred SHR
arteries
membranes
potassium
acetylcholine
cholecalciferol
Language English
Date 1999-10-01
Published in Hypertension. Philadelphia: Lippincott Williams & Wilkins, v. 34, n. 4, p. 897-901, 1999.
ISSN 0194-911X (Sherpa/Romeo, impact factor)
Publisher Lippincott Williams & Wilkins
Extent 897-901
Origin https://doi.org/10.1161/01.HYP.34.4.897
Access rights Open access Open Access
Type Article
Web of Science ID WOS:000083486500035
URI http://repositorio.unifesp.br/11600/43887

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