Soft tissue calcium and magnesium content in acute pancreatitis in the dog: calcium accumulation, a mechanism for hypocalcemia in acute pancreatitis
Bhattacharya, S.K.; Luther, R.W.; Pate, J.W.; Crawford, A.J.; Moore, O.F.; Pitcock, J.A.; Palmieri, G.M.; Britt, L.G.
Journal of Laboratory and Clinical Medicine 105(4): 422-427
1985
ISSN/ISBN: 0022-2143 PMID: 2580033 Document Number: 244839
The mechanism of hypocalcemia in acute pancreatitis remains unknown despite continued investigative work over the past several decades. Because acute pancreatitis is accompanied by multiple systemic manifestations and alterations of plasma membranes, the possibility that an abnormal translocation of Ca from extracellular to intracellular compartments could play a role in hypocalcemia of acute pancreatitis was investigated in dogs. Acute pancreatitis was induced by injecting bile into the pancreatic duct. Plasma Ca, Mg and amylase concentrations were determined. Ca and Mg contents were also measured in biopsy specimens of pancreas, liver, skeletal muscle and kidney before and after induction of acute pancreatitis. As expected, hypocalcemia and hyperamylasemia occurred 6 h after induction of pancreatitis, and persisted throughout the experiment, 13-25 h. Plasma Mg concentration fell at 6 and 18 h and returned to an almost normal level by the end of the study. A significant elevation in Ca content of pancreas (71%), liver (24%) and muscle (112%), and 25% reduction of Ca in kidney were observed in dogs with histologic signs of pancreatitis. However, tissue Mg concentration fell in pancreas (18%) but remained unchanged in the other tissues investigated. No significant changes in any variables were detected in sham-operated animals. In another group of dogs in which the accessory pancreatic duct was not occluded when bile was injected, the histologic lesions were extremely mild, although the plasma Ca concentration and the pancreatic Ca and Mg contents were altered just as much as in the severely affected dogs. The hypocalcemia of acute pancreatitis may be the result, at least in part, of accumulation of Ca in soft tissues. The decreased Ca content in kidney could be related to hypocalcemia. Because Ca content in pancreas was uniformly elevated in animals with severe and mild pancreatitis, it is postulated that Ca accumulation in acute pancreatitis is not solely the result of necrosis but is an early biochemical event in the pathogenesis of systemic manifestations of this disorder. Abnormally high levels of circulating pancreatic enzymes such as amylase and lipase may cause widespread plasma membrane alterations, thus stimulating significant Ca accumulation in distant soft tissues, especially in muscle.