Chromogranin-B regulation of IAPP and insulin secretion.
In the endocrine pancreas, chromogranin-A and pancreastatin have been suggested to inhibit islet insulin secretion, whereas chromogranin-B has not been studied in this context. Furthermore, a putative effect by chromogranins on IAPP secretion is unknown. We aimed to elucidate the endogenous effect of chromogranin-A, pancreastatin and chromogranin-B on islet insulin and IAPP secretion from pancreatic NMRI mouse islets. In acute experiments, there was a tendency towards an increase in insulin release, which became more manifest after a 48-h exposure. Moreover, 48 h exposure to chromogranin-B antiserum resulted in a significant increase in (pro)insulin synthesis. Neither antibodies against chromogranin-A nor pancreastatin had any effect on islet hormone secretion. None of the antibodies tested had any effect on islet IAPP or insulin content. We suggest that chromogranin-B released from islets may have an autocrine inhibitory effect on islet IAPP and insulin secretion. Our data imply a regulatory role of chromogranin-B in islet IAPP and insulin secretion.
Karlsson
E
E
Department of Medical Cell Biology, Biomedicum, Uppsala University, Sweden. ella.karlsson@medcellbiol.uu.se
Stridsberg
M
M
Sandler
S
S
D000682:Amyloid / Q000378:metabolism*; D000818:Animals; D053379:Chromogranin A; D053378:Chromogranin B; D002864:Chromogranins / Q000276:immunology / Q000378:metabolism*; D046508:Culture Techniques; D006728:Hormones / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D058228:Islet Amyloid Polypeptide; D007515:Islets of Langerhans / Q000378:metabolism*; D008297:Male; D051379:Mice; D010187:Pancreatic Hormones / Q000276:immunology / Q000378:metabolism; D011384:Proinsulin / Q000096:biosynthesis; D014176:Protein Biosynthesis; D011817:Rabbits; D013997:Time Factors
D000682:Amyloid; C506134:CHGB protein, human; D053379:Chromogranin A; D053378:Chromogranin B; D002864:Chromogranins; D006728:Hormones; D007328:Insulin; D058228:Islet Amyloid Polypeptide; D010187:Pancreatic Hormones; C506137:chromogranin B, mouse; C050836:pancreastatin; D011384:Proinsulin