Effect of nitric oxide on electric and mechanical activities of gastric antral circular muscles in guinea pigs.
OBJECTIVE
To study the effect of exogenous nitric oxide (NO) on electric and mechanical activities of gastric antral circular muscle in guinea pigs in vitro.


METHODS
Mechanical and electric activities of gastric antral circular muscle in guinea pigs were recorded simultaneously.


RESULTS
Sodium nitroprusside (SNP, 0.5 mumol.L-1), an NO donor, inhibited the frequency and amplitude of fast wave and spontaneous contraction of the strips (P < 0.01). SNP-induced inhibition was not blocked by tetrodotoxin, atropine, phentolamine, and propranolol (P > 0.05), but diminished by methylene blue (P < 0.01) and oxyhemoglobin (P < 0.01).


CONCLUSIONS
Exogenous NO inhibits gastric antral myoelectric and mechanical activities in guinea pigs. The inhibitions are produced by NO acting on extracellular membrane and enhancing the level of cGMP.
Jin
J Y
JY
Research Laboratory of Digestive Physiology, College of Medicine, Yanbian University, China.
Li
Z H
ZH
Li
Z J
ZJ
Jin
Z Y
ZY
Jin
N G
NG
Li
Y
Y
Xu
W X
WX
Li
Z L
ZL
D000818:Animals; D004594:Electrophysiology; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000502:physiology; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D009599:Nitroprusside / Q000494:pharmacology*; D013270:Stomach / Q000502:physiology*
D020030:Nitric Oxide Donors; D009599:Nitroprusside