Effects of substance P on electric activity of mouse pancreatic islet cells in vitro.
The effects of substance P (SP), [D-Pro2, D-Trp7,9]SP and verapamil on the electric activity of B cells of Langerhans islets of mice were investigated. Addition of SP 100 nmol.L-1 to the perfusion medium stimulated spontaneous electric activity induced by glucose 5.5 mmol.L-1 with an increase in frequency and amplitude of the spikes. [D-Pro2, D-Trp7,9]SP 50 nmol.L-1 reversed the stimulative effect of SP. There was no evidence for an enhancing interaction between SP and acetylcholine 1 mumol.L-1. Verapamil 60 mumol.L-1 blocked the stimulative effect of SP. These results suggest that the stimulative effect of SP on the electric activity of B cells may be due to the increase in Ca2+ influx through the voltage-dependent Ca2+ channels.
Fu
X W
XW
Department of Physiology, Shanghai Medical University, China.
Shen
X M
XM
Su
Q F
QF
Zhang
J R
JR
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D007515:Islets of Langerhans / Q000502:physiology*; D008564:Membrane Potentials; D051379:Mice; D013373:Substance P / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D014700:Verapamil / Q000494:pharmacology
D013373:Substance P; C032132:substance P, prolyl(2)-tryptophan(7,9)-; D014700:Verapamil; D000109:Acetylcholine