Galanin inhibition of cholecystokinin-8-induced increase in [Ca2+]i in individual rat pancreatic B-cells.
The intracellular free Ca2+ ion concentration [( Ca2+]i) was measured in individual rat pancreatic B-cells loaded with fura-2. The cells were prepared by enzymatic digestion and fluorescence-activated cell sorting. The resting concentration of [Ca2+]i in B-cells was 126.3 +/- 3.1 nM in the presence of 4.4 mM glucose. Addition of cholecystokinin-8 (CCK-8) resulted in rapid and transient rises in [Ca2+]i. Perifusion of B-cells with galanin attenuated the amplitude and duration of CCK-8-induced [Ca2+]i changes and this inhibitory effect was concentration-dependent and reversible. Perifusion of B-cells with nifedipine, a voltage-sensitive Ca2+ channel blocker, reduced the duration of the [Ca2+]i increase induced by CCK-8, indicating that the Ca2+ entry from the extracellular space was, at least in part, involved in CCK-8-induced increases in [Ca2+]i.
MRC Regulatory Peptide Group, University of British Columbia, Vancouver, Canada.
J
J
Wang
Y N
YN
Kwok
K G
KG
Baimbridge
J C
JC
Brown
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D046508:Culture Techniques / Q000379:methods; D005456:Fluorescent Dyes; D016257:Fura-2 / Q000031:analogs & derivatives; D019004:Galanin; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D009543:Nifedipine / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012844:Sincalide / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D013050:Spectrometry, Fluorescence
D005456:Fluorescent Dyes; D010455:Peptides; C049925:fura-2-am; D019004:Galanin; D009543:Nifedipine; D012844:Sincalide; D002118:Calcium; D016257:Fura-2