Vasoactive intestinal polypeptide alters GH3/B6 pituitary cell excitability.
The effects of the prolactin secretagogue vasoactive intestinal peptide (VIP) on the membrane excitability of clonal prolactin-secreting (GH3/B6) cells were studied using the whole-cell configuration of the patch recording technique. Submicromolar concentrations of VIP affected membrane excitability in more than half the cells tested, increasing the frequency of spontaneous Ca2+-dependent action potentials and prolonging individual action potentials, as well as changing their rheobase. Under voltage clamp, VIP induced changes in several voltage-sensitive conductances at both instantaneous and steady-state times. Some of these changes in membrane excitability may be related to VIP's stimulatory effects on prolactin secretion.
Hedlund
B
B
Department of Biochemistry, Arrhenius Laboratory, University of Stockholm, Sweden.
Dufy
B
B
Barker
L
L
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D004553:Electric Conductivity; D008564:Membrane Potentials / Q000187:drug effects; D010911:Pituitary Neoplasms; D051381:Rats; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
D014660:Vasoactive Intestinal Peptide; D002118:Calcium