[Effect of a protein-deficient diet (5 p. 100 gluten) and of balanced refeeding (15 p. 100 casein) on potential lipase, colipase-dependent lipase and phospholipase A2 activities. I. In the growing rat pancreas].
The intake of a 5 p. 100 gluten diet as the only protein source caused an overall protein synthesis deficiency that immediately stopped the rat growth. At first, the pancreas was less affected than the rest of the organism, but after 29 days of malnutrition, there was a 40 p. 100 decrease in body and pancreatic weight. The protein level of the deficient pancreas remained at that of the controls. Refeeding caused a considerable but temporary increase in that level after 24 h. The specific enzyme activities (AS) showed high variations from one day to the other, but only phospholipase A2 AS was significantly affected by the deficiency (--50 p. 100). Total lipase activities of the pancreas were reduced by 50 p. 100 and those of phospholipase A2 by 70 p. 100. Refeeding caused a considerable increase in lipase activities in 12 h and in phospholipase A2 activity in 48 h, but this process was brief and did not indicate complete recovery of those activities. After 27 days of refeeding, only phospholipase A2 showed good levels. Adding methionine to the deficient diet only changed the colipase level; this constitutes one more argument in favor of a distinct synthesis for this factor and for lipase.