Role of cyclic adenosine monophosphate in amylase release from dissociated rat pancreatic acini

Abstract

SUMMARY1. The effect ofoctapeptide of cholecystokinin-pancreozymin (CCK8), bethanechol, cholera toxin, glucagon and vasoactive intestinal polypeptide (VIP) on amylase secretion and lactic dehydrogenase (LDH) release from isolated rat pancreatic acini was studied.2. In isolated rat pancreatic acini, in the absence of theophylline in the medium, amylase secretion was increased by 65-78 % with 10-7 and 10-6 M-cholera toxin. In the presence of theophylline, amylase secretion was increased by 43-56 % with 10-7 and 10-6 M-cholera toxin following a 90 min incubation. No effect was observed in the presence of theophylline at 30 and 60 min. The effect of cholera toxin was potentiated by CCK8 at 60 and 90 min.3. In the absence of theophylline in the medium, amylase secretion was increased by 81-118 % with 10-5 and 10-4 M-glucagon and 86 % with 10-6 M-VIP at 60 min. In the presence of theophylline in the medium, amylase secretion was increased by 53-246% with 10-9 to 10-6M-glucagon and 111-158% with 10-7 and 10-6 M-VIP respectively. The effect of glucagon and VIP was potentiated by CCK8.4. Potentiation of the rate of amylase release due to glucagon (10-5 M) and VIP (10-6 M) occurred during the first 15 min of incubation.5. Release of LDH was not increased by any of these agents. 6. It is concluded that cyclic AMP rise (due to cholera toxin, glucagon and VIP effect) increased amylase secretion from rat pancreatic acinar cells. This effect is less marked than in the guinea-pig pancreas and is potentiated by agents mobilizing cellular Ca2+ (CCK8 and bethanechol).7. These data indicate species-specific variation in the action of cyclic AMP in the pancreas.

Interaction of cholecystokinin and vasoactive intestinal polypeptide on function of mouse pancreatic acini in vitro.

“…In mouse pancreas especially, agonists working via cyclic AMP have little or no effect on amylase secretion. Recently, it has been shown for rat pancreatic acini that agents acting via cyclic AMP, although having only a small effect by themselves, potentiate those agonists acting via calcium (Singh, 1979; Collen, Sutliff, Singh, 1982). We therefore carried out studies to evaluate this phenomenon in isolated mouse pancreatic acini.…”

Different Secretory Response of Pancreatic Isolated Lobules and Dissociated Acini from Hypothyroid Rats to Exogen TRH

“…The sensitivity of the assay was 0.47 ± 0.1 pg/tube (N= 5). The intra-assay variation ranged Amylase Secretion from Dissociated Acini Dissociated acini were prepared by a previously described method (Singh, 1982). Starting material was 0.9-1.2 g of pancreas obtained from 2 male Wistar rats.…”

Alteraciones en células secretoras del páncreas exocrino en modelos experimentales de fibrosis quística y pancreatitis aguda

“…54,55 Aunque los mecanismos moleculares por los que la activación de la PKA induce la secreción enzimática en acinos pancreáticos apenas se han investigado, se sabe desde hace mucho tiempo que existe una potenciación de la respuesta secretora ante la estimulación conjunta con secretagogos que actúan por la vía del Ca 2+ y por la vía del cAMP. 316 Por otra parte, como se ha revisado en el apartado correspondiente a la regulación de la secreción en células ductulares, últimamente se le está dedicando bastante atención al posible papel de las proteínas Epac como efectores intracelulares del cAMP en las células acinares pancreáticas. 55…”

“…55 Tomando como partida estos resultados, quisimos comprobar si el 8-pCPT modifica la respuesta secretora de los conductos estimulados con carbacol. muchos años, 316 si bien los mecanismos moleculares implicados en estos procesos todavía no se han aclarado. Tras el descubrimiento de las proteínas Epac como efectores intracelulares del cAMP, se está dedicando bastante atención a su posible intervención en las interacciones entre ambas rutas de señalización.…”