Decrease in the Number of Muscarinic Receptors in Rat Pancreas after Chronic Alcohol Intake

Abstract
The effect of eight months of alcohol intake on the number and affinity of muscarinic receptor sites in the rat pancreatic tissue were measured by using N‐3H‐methylscopolamine (NMS) as a radioligand. There were no differences in the receptor affinities for NMS between the alcohol‐exposed and age‐matched control animals, but the number of muscarinic receptor sites was 60 percent lower in the alcoholic animals. The present experimental model is consistent with altered food and water intake as consequences of chronic alcoholism and thus changes in food and water consumption may participate in mediating the effects of chronic alcohol intake on NMS binding sites. We suggest that the previously reported marked alcohol‐induced increase in pancreatic acetylcholine levels, which has been proposed to play a crucial role in the pathogenesis of acute alcoholic pancreatitis, may be a secondary phenomenon induced by increased resistance at the muscarinic receptor level.