title: Central neural mechanism contributing to attenuation of angiotensin II-induced hypertension in rats on dietary calcium supplementation.
abstract: The effect of dietary calcium (Ca) supplementation on blood pressure (BP) and the central nervous system (CNS) mechanism underlying this effect were studied in angiotensin II (Ang II)-induced hypertensive rats. The effects of dietary Ca (0.5, 2, 4%) on systolic blood pressure (SBP), ionized Ca concentration (Ca++) in cerebrospinal fluid (CSF) and central norepinephrine (NE) turnover were investigated in male Wistar rats receiving subcutaneous infusion of Ang II (100 ng/min). Central NE turnover was studied by measuring 3-methoxy-4-hydroxyphenylglycol (MHPG) concentration in CSF with multiple electrode liquid chromatography. Ang II significantly increased SBP, and dietary Ca dose-dependently attenuated the increase. SBP inversely correlated with Ca++ and MHPG in CSF. Intracerebroventricular injection of CaCl2 more markedly reduced BP in Ang II-treated rats than that in control rats. These results suggest that modulation of central NE turnover possibly caused by the increase in CNS Ca++ is involved in the anti-hypertensive mechanism of dietary Ca supplementation in Ang II-induced hypertensive rats.
authors: Department of Geriatrics, Faculty of Medicine, University of Tokyo, Japan.
authors: S
authors: S
authors: Kim
authors: Y
authors: Y
authors: Ouchi
authors: S
authors: S
authors: Iijima
authors: K
authors: K
authors: Toba
authors: H
authors: H
authors: Orimo
mesh_terms: D000804:Angiotensin II / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002118:Calcium / Q000097:blood / Q000134:cerebrospinal fluid; D002136:Calcium, Dietary / Q000008:administration & dosage*; D002490:Central Nervous System / Q000187:drug effects / Q000503:physiopathology*; D004231:Diuresis / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006973:Hypertension / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D008297:Male; D008734:Methoxyhydroxyphenylglycol / Q000134:cerebrospinal fluid; D009318:Natriuresis / Q000187:drug effects; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
chemical_list: D002136:Calcium, Dietary; D000804:Angiotensin II; D008734:Methoxyhydroxyphenylglycol; D002118:Calcium; D009638:Norepinephrine