[Chronic calcifying pancreatitis, pancreatic calculi. New data].

There are two different forms of chronic pancreatitis: one is obstructive pancreatitis which results from a pre-existing obstacle (usually a tumour or a scar) and the other, much more frequent, is chronic calcifying pancreatitis which seems to begin with the formation of precipitates in acini and ducts, later transformed into stones and calcifications made up of calcium carbonate, and therefore is a pancreatic lithiasis. Since the pancreatic juice is supersaturated in calcium carbonate, the presence of an inhibitor of crystallization must be postulated. This has now been identified as a 13500 daltons molecular weight protein: the pancreatic stone protein secreted by the acinar cells. This protein is decreased in chronic calcifying pancreatitis irrespective of its origin (alcoholic, hereditary, hypercalcaemic, tropical, idiopathic), although its reduction is unrelated to any of these aetiological factors. Chronic alcohol consumption may encourage calcium stone formation possibly by disturbing the cholinergic regulation of pancreatic secretion, with decrease in citrate secretion (citrate is a chelator of calcium) and increase in enzyme secretion. The diagnostic and therapeutic implications of these findings are already obvious.