Enhanced endothelium-independent vasodilator response to calcitonin gene-related peptide in hypertensive rats.
In isolated superior mesenteric arteries, vasodilation induced by calcitonin gene-related peptide (CGRP) was significantly larger in 12-week-old spontaneously hypertensive rats (SHR) than Wistar-Kyoto rats (WKY). In WKY and 6-week-old SHR, most of the vasodilator response to CGRP was abolished by Nw-nitro-L-arginine and indomethacin. In contrast, the inhibitors caused no significant change in the response in 12-week-old SHR. Vasodilations induced by acetylcholine and isoproterenol were smaller in 12-week-old SHR than WKY, and that induced by sodium nitroprusside was comparable in both tissues. These results suggest that endothelium-independent vasodilator activity of CGRP is enhanced in hypertensive SHR, which overwhelms the decreased endothelium-dependent effects.
Department of Pharmacology, Institute of Basic Medical Sciences, University of Tsukuba, Ibaraki, Japan.
Y I
YI
Tomobe
T
T
Ishikawa
K
K
Goto
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000503:physiopathology; D006973:Hypertension / Q000503:physiopathology*; D066298:In Vitro Techniques; D008297:Male; D017538:Mesenteric Artery, Superior / Q000187:drug effects* / Q000503:physiopathology; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D014664:Vasodilation / Q000187:drug effects*
D015740:Calcitonin Gene-Related Peptide