Role of inducible nitric oxide synthase in rostral ventrolateral medulla in blood pressure regulation in spontaneously hypertensive rats.
Nitric oxide (NO) in the brainstem modulates blood pressure (BP). Overexpression of inducible NO synthase (iNOS) in the rostral ventrolateral medulla (RVLM) increases BP in normotensive Wistar-Kyoto rats (WKY), but its role in BP regulation in spontaneously hypertensive rats (SHR) is unknown. We examined iNOS expression and the effect of iNOS inhibitors in the RVLM on BP and heart rate in SHR and WKY. iNOS levels in the RVLM were significantly higher in SHR than in WKY. Bilateral microinjection of aminoguanidine into the RVLM dose-dependently decreased BP and heart rate in SHR, but not in WKY. These findings suggest that iNOS expression in the RVLM of SHR contributes to increase BP.
Kimura
Yoshikuni
Y
Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan.
Hirooka
Yoshitaka
Y
Kishi
Takuya
T
Ito
Koji
K
Sagara
Yoji
Y
Sunagawa
Kenji
K
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D006146:Guanidines / Q000008:administration & dosage / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006973:Hypertension / Q000201:enzymology* / Q000503:physiopathology; D008297:Male; D008845:Microinjections; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D020651:Ventral Thalamic Nuclei / Q000201:enzymology*
D006146:Guanidines; D052247:Nitric Oxide Synthase Type II; C004479:pimagedine