[Histological, histoenzymatic and biochemical study of the liver and small intestine of rats during short periods of starvation].

The structure and the activity of acid phosphatase, beta-glucuronidase, alkaline phosphatase and ATP-ase in the liver and small intestine of rats receiving for 20 days a one-time, fixed at a certain time (2 o'clock) feeding was studied morphologically in dynamics in 2, 6, 24 and 48 hours after the last feeding. Furthermore, parallel with this the activity of acid phosphatase, beta-glucuronidase, alpha-glucosidase and beta-acetylglucosaminidase was determined in homogenates by biochemical methods. Alongside the total activity free activity of beta-acetylglucosaminidase and the activity of this enzyme in the blood plasma was defined. It is shown that during fasting, especially by the 48th hour, there takes place a significant activation of lysosomal enzymes both in the liver and in the small intestine (in the cells of the cylindrical epithelium). A significantly increased permeability of lysosomal membranes (mounting free activity of beta-acetylglucosaminidase) in the liver and of plasmic hepatocytes membranes (higher activity of the enzyme in the blood plasma) was also ascertained. The activation of the lysosomal enzymes is considered to be an adaptive reaction of the organism in fasting.