Mecamylamine, a nicotinic receptor channel antagonist, affects amylase secretion by isolated pancreatic acinar cells.

It is well established that CCK is a potent stimulator of amylase secretion from the pancreatic acinar cells, while nicotine is an effective inhibitor of such secretion. The present study was conducted to determine whether mecamylamine, a well-established ganglionic blocker drug, could influence amylase secretion from the pancreas. Male Sprague-Dawley rats were fasted, sacrificed, the pancreas removed, and pancreatic acinar cells isolated and purified. The cells were equally divided into 4 different flasks and treated with the following solutions: (control), 10 mM nicotine, 10 microM mecamylamine or 100 microM mecamylamine. The cells were washed twice after 30 min incubation at 37 degrees C, resuspended in HR buffer, and amylase release in response to graded doses of CCK-8 was measured in cells from each flask. The study was repeated four times. Basal amylase release was not different by treatment with nicotine or different doses of mecamylamine. In response to CCK-8, amylase release was decreased by nicotine and by mecamylamine (100 microM) when compared with control. Amylase release was similar between control and mecamylamine (10 microM). Peak amylase released with the maximal dose of CCK-8 (1 x 10(-10) M) was less in cells treated with nicotine when compared with those measured cells treated with saline or with the two doses of mecamylamine. The release of amylase was suppressed in a similar manner in all treatment groups in response to supramaximal (3 x 10(-10) to 1 x 10(-9) M) doses of CCK-8. Mecamylamine, at the high dose, acts on isolated pancreatic acinar cells to decrease amylase release in a manner similar to that found with nicotine. Both of these drugs, nicotine and mecamylamine, may act via CCK receptors via two different intracellular mechanisms.