Role of calcium in the bombesin-induced intestinal CCK release in rats.
In the isolated vascularly perfused rat duodenojejunum, vascular infusion of bombesin (100 nM) provoked an early, transient (6 min) release of CCK (500% of basal), followed by a sustained response (400% of basal). The calcium chelator EGTA (2 mM) reduced the early peak and abolished the second phase of CCK release. A similar variation was evoked by verapamil (10 microM), whereas diltiazem (100 microM), nifedipine (50 microM), and omega-conotoxin (100 nM) had no significant effect. It is concluded that bombesin-induced CCK release from rat intestine is dependent on the availability of extracellular calcium and on the activation of calcium channels sensitive to blockers of the phenylalkylamine family.
Aucouturier
S
S
INSERM Unité 45, Hôpital E. Herriot, Lyon, France.
Cuber
J C
JC
Bernard
C
C
Chayvialle
J A
JA
D000818:Animals; D001839:Bombesin / Q000494:pharmacology*; D002118:Calcium / Q000502:physiology*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002766:Cholecystokinin / Q000378:metabolism*; D004110:Diltiazem / Q000494:pharmacology; D066298:In Vitro Techniques; D007421:Intestine, Small / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009543:Nifedipine / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014700:Verapamil / Q000494:pharmacology; D020960:omega-Conotoxins
D002121:Calcium Channel Blockers; D010455:Peptides; D020960:omega-Conotoxins; C053423:Conus magus toxin; D002766:Cholecystokinin; D014700:Verapamil; D004110:Diltiazem; D009543:Nifedipine; D001839:Bombesin; D002118:Calcium