CCK and gastrin inhibit adenylate cyclase activity through a pertussis toxin-sensitive mechanism in the tumoral rat pancreatic acinar cell line AR 4-2J.
(Thr28,Nle31)CCK(23-33) (CCK-9) and gastrin(1-17)I (gastrin) inhibited adenylate cyclase activity in membranes from the tumoral rat pancreatic acinar cell line AR 4-2J through a Bordetella pertussis toxin-sensitive mechanism. This contrasted with the stimulatory effect exerted by CCK-9 on adenylate cyclase activity in membranes from normal rat pancreas. The relative potency of CCK-9, gastrin, and related peptides in inhibiting adenylate cyclase, when confronted with previous evidence, suggests that 'non-selective CCK-gastrin CCK-B receptors' predominating over 'selective CCK-A receptors' in the AR 4-2J cell line, favored the coupling of the first receptors to adenylate cyclase through Gi, while CCK-A receptors capable of stimulating the enzyme through Gs were detected only after Bordetella pertussis toxin pretreatment.
Scemama
J L
JL
Department of Biochemistry and Nutrition, Medical School, Université Libre de Bruxelles, Belgium.
Robberecht
P
P
Waelbroeck
M
M
De Neef
P
P
Pradayrol
L
L
Vaysse
N
N
Christophe
J
J
D037361:Adenylate Cyclase Toxin; D000067956:Adenylyl Cyclase Inhibitors; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D002766:Cholecystokinin / Q000494:pharmacology*; D005755:Gastrins / Q000494:pharmacology*; D006160:Guanosine Triphosphate / Q000494:pharmacology; D010179:Pancreas / Q000201:enzymology*; D010190:Pancreatic Neoplasms / Q000201:enzymology*; D010418:Pentagastrin / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology; D037342:Pertussis Toxin; D051381:Rats; D012633:Secretin / Q000494:pharmacology; D013758:Tetragastrin / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
D037361:Adenylate Cyclase Toxin; D000067956:Adenylyl Cyclase Inhibitors; D005755:Gastrins; D010446:Peptide Fragments; D010566:Virulence Factors, Bordetella; D013758:Tetragastrin; C053399:cholecystokinin 9; D012633:Secretin; D014660:Vasoactive Intestinal Peptide; D006160:Guanosine Triphosphate; D002766:Cholecystokinin; D037342:Pertussis Toxin; D010418:Pentagastrin