[Effects of substance P on the contractile response of longitudinal muscle of rat ileum to 5-HT].
The purpose of this study was to observe the effects of substance P (SP) on the contractile response of longitudinal muscle with myenteric plexus (LM-MP) of rat ileum induced by 5-HT in vitro and to analyse its mechanism. The results were as follows: (1) Subthreshold dose of SP (5 nmol/L) potentiated the 5-HT-induced contractile response; (2) Both [D-Pro2 D-Trp7,9]-SP and atropine inhibited or blocked this potentiated effect suggesting that the effect was mediated by SP receptors; (3) This effect was not blocked by bromolysergic acid diethylamide (BOL). The results suggest that SP of subthreshold dose might modulate the effect of 5-HT, and a cholinergic mechanism might be involved in the modulation.
Xiao
Q A
QA
Li
D S
DS
Dai
Y L
YL
Ge
Z H
ZH
D000818:Animals; D005260:Female; D007082:Ileum / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000502:physiology*; D013373:Substance P / Q000502:physiology*
D012701:Serotonin; D013373:Substance P