Effects of zinc and copper deficiency associated with protein or lipid deficiency on rat exocrine pancreatic secretion

Copper and zinc are both secreted by the pancreas but are necessary for pancreatic secretion. We have studied the effects of a 4- or 8-week zinc or copper-deficient diet associated with or without lipid or protein deficiency on rat pancreatic secretion after stimulation by secretin, cerulein, or intraduodenal oleic acid. Twenty animals were in the control group; 40 rats were fed a copper-deficient diet (20 copper-deficient only and 20 copper- plus lipid-deficient). Ninety rats were deprived of zinc (30 of zinc-deficient only, 30 zinc-plus protein-deficient, 30 of zinc- plus lipid-deficient). Only the zinc- plus lipid-deficient diet for 8 weeks decreased basal bicarbonate and basal protein secretion (-42 and -70%, respectively, of the control values). Stimulated secretion was not markedly altered by copper deficiency while zinc deficiency, zinc plus protein deficiencies, and zinc plus lipid deficiencies suppressed almost responses to hormonal stimulation: After 8 weeks, the maximal protein response to oleic acid was reduced to 19.00 +/- 3.40, 18.58 +/- 3.00, and 12.04 +/- 2.91 microgram/30 min/g body weight in zinc- zinc and protein-; and zinc- and lipid-deficient diet, respectively, versus 39.87 +/- 6.33 microgram/30 min/g body weight (p less than 0.05) in controls. In all types of stimulation, lipid deficiency potentiated the deleterious effect of zinc deficiency on pancreatic secretion. This might be paralled with an extremely low level of lipid in the diet of people living in countries in which nutritional pancreatitis is observed and with the relative risk of developing an alcoholic chronic pancreatitis being increased by a low fat diet.