Control of pancreatic amylase release in vitro: effects of ions, cyclic AMP, and colchicine

Article date: September 1972

By: L. BENZ, B. ECKSTEIN, E. K. MATTHEWS, J. A. WILLIAMS in Volume 46, Issue 1, pages 66-77

. The time course and concentration‐response relationship of amylase release from pieces of guinea‐pig pancreas in vitro in response to bethanechol and pancreozymin was determined.

. Removal of Ca++ from the medium had no effect on basal amylase release but abolished the stimulating effect on release of bethanechol.

. Elevation of the concentration of Mg++ in the medium increased basal amylase release and reduced the response to bethanechol.

. Elevation of the concentration of K+ in the medium increased amylase release; this effect was blocked by a concentration of atropine which blocked also the response to bethanechol.

. Cyclic AMP, dibutyryl cyclic AMP and theophylline failed to stimulate amylase release. Pancreatic cyclic AMP concentrations were found not to be increased by bethanechol, pancreozymin or an elevated concentration of K+ in the medium.

. Colchicine had no effect on basal amylase release or the response to bethanechol or pancreozymin.

. It is concluded that the coupling of stimulus to secretion involves ionic control but that neither cyclic AMP production nor microtubular mechanisms play a major role in controlling exocytosis in the pancreatic acinar cell. These findings are discussed in relation to the stimulus‐secretion coupling processes in other cells.

. The time course and concentration‐response relationship of amylase release from pieces of guinea‐pig pancreas in vitro in response to bethanechol and pancreozymin was determined.

. Removal of Ca++ from the medium had no effect on basal amylase release but abolished the stimulating effect on release of bethanechol.

. Elevation of the concentration of Mg++ in the medium increased basal amylase release and reduced the response to bethanechol.

. Elevation of the concentration of K+ in the medium increased amylase release; this effect was blocked by a concentration of atropine which blocked also the response to bethanechol.

. Cyclic AMP, dibutyryl cyclic AMP and theophylline failed to stimulate amylase release. Pancreatic cyclic AMP concentrations were found not to be increased by bethanechol, pancreozymin or an elevated concentration of K+ in the medium.

. Colchicine had no effect on basal amylase release or the response to bethanechol or pancreozymin.

. It is concluded that the coupling of stimulus to secretion involves ionic control but that neither cyclic AMP production nor microtubular mechanisms play a major role in controlling exocytosis in the pancreatic acinar cell. These findings are discussed in relation to the stimulus‐secretion coupling processes in other cells.

DOI: 10.1111/j.1476-5381.1972.tb06849.x

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