Involvement of nitric oxide in the response to 5-hydroxytryptamine in the rat in-vivo.
The involvement of nitric oxide (NO) in the effects of 5-HT on intestinal secretion and cardiovascular function in anaesthetized rats was investigated using NG-nitro-L-arginine methyl ester (L-NAME), a specific NO-synthase antagonist, and its optical isomer D-NAME. L-NAME significantly reduced the prolonged hypotensive response to 5-HT. It also caused a small rightward shift in the colonic 5-HT dose-response curve. This suggests that NO plays a significant role in the prolonged hypotensive response to 5-HT, and may make a small contribution to the secretory response of the colon, but not that of the jejunum, in the rat in-vivo.
Franks
C M
CM
Department of Biomedical Science, Sheffield University, UK.
Hardcastle
J
J
Hardcastle
P T
PT
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D003106:Colon / Q000187:drug effects / Q000378:metabolism; D004594:Electrophysiology; D006339:Heart Rate / Q000187:drug effects; D007419:Intestinal Secretions / Q000187:drug effects* / Q000502:physiology; D007583:Jejunum / Q000187:drug effects / Q000378:metabolism; D008297:Male; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000008:administration & dosage / Q000494:pharmacology*
D009569:Nitric Oxide; D012701:Serotonin; D001120:Arginine; D019331:NG-Nitroarginine Methyl Ester