[TIC4]endomorphins, analogues of endomorphins, have significantly enhanced vasorelaxant effects in rat aorta rings.
[Tic(4)]EM1 and [Tic(4)]EM2, new endomorphins (EMs) analogues, caused relaxation of rat aorta rings precontracted with phenylphrine in a concentration-dependent manner and were 240- to 370-fold more potent than EMs. This effect was inhibited by endothelium removal or by incubation with NO synthase inhibitor L-NNA or opioid receptor antagonist naloxone. The results demonstrate that [Tic(4)]EMs have NO- and endothelium-dependent vasorelaxant effects which are mediated by the opioid receptor.
Zhao
Qian-Yu
QY
Department of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, Peoples Republic of China.
Chen
Qiang
Q
Feng
Yun
Y
Lin
Xin
X
Wang
Rui
R
D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D019335:Nitroarginine / Q000494:pharmacology; D009842:Oligopeptides / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D017450:Receptors, Opioid, mu / Q000502:physiology; D044005:Tetrahydroisoquinolines / Q000737:chemistry*; D014664:Vasodilation / Q000187:drug effects*
D009842:Oligopeptides; D017450:Receptors, Opioid, mu; D044005:Tetrahydroisoquinolines; C105293:endomorphin 1; D019335:Nitroarginine; C078986:1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid; C105294:endomorphin 2; D019001:Nitric Oxide Synthase