Inhibition of glucose-stimulated insulin release in the perfused rat pancreas by parathyroid secretory protein-I (chromogranin-A).
The effect of graded doses (10(-10)-10(8) M) of highly purified bovine parathyroid secretory protein-I (SP-I; chromogranin-A) or synthetic porcine pancreastatin on glucose-stimulated insulin release in the perfused rat pancreas was examined. SP-I (10(-9) M) inhibited the first phase of glucose-stimulated insulin release, and 10(-8) M SP-I inhibited both the first and second phases of glucose-stimulated insulin release; 10(-10) M SP-I was inactive. In comparison, pancreastatin at 10(-10) M inhibited the first phase of insulin release, and at 10(-9) and 10(-8) M, pancreastatin inhibited both phases of insulin release. The inhibition by SP-I was achieved at concentrations that normally exist in the general circulation of man. These and other data suggest that circulating SP-I plays a physiological role in the regulation of insulin secretion.
Greeley
G H
GH
Department of Surgery, University of Texas Medical Branch, Galveston 77550.
Thompson
J C
JC
Ishizuka
J
J
Cooper
C W
CW
Levine
M A
MA
Gorr
S U
SU
Cohn
D V
DV
D000818:Animals; D053379:Chromogranin A; D002864:Chromogranins / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005947:Glucose / Q000494:pharmacology*; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D008297:Male; D009419:Nerve Tissue Proteins / Q000494:pharmacology*; D010179:Pancreas / Q000187:drug effects / Q000378:metabolism*; D010187:Pancreatic Hormones / Q000008:administration & dosage / Q000494:pharmacology; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains
D053379:Chromogranin A; D002864:Chromogranins; D007328:Insulin; D009419:Nerve Tissue Proteins; D010187:Pancreatic Hormones; C506153:chromogranin A, rat; C050836:pancreastatin; D005947:Glucose