[Changes in the serum alkaline phosphatase of sheep and cattle with acute acidosis of the forestomach].

Experimental acidosis of the forestomach was induced in 6 lambs and 29 ewes and rams, using starch (5-10 g/kg body mass), lactic acid (0.4-0.5 per cent of the live weight) or concentrates (50-60 g/kg body mass). Acidosis occurred spontaneously in 10 calves and 14 cows following the intake of great amounts of molasses. The changes were followed up in the total activity and properties of the alkaline phosphatase in the blood serum of the diseased animals. It was found that the total activity of the enzyme in the blood serum of the test animals dropped at the 24th hour after the beginning of the experiment, reached its lowest point at the 48th-72nd hour (50 to 70 per cent drop as compared to the initial level), and was still under the initial level with part of the test animals at the 96th hour. The decrease in the total activity of the enzyme in the blood serum was found to be linked with changes in its properties - the resistance to 1-phenylalanine rose, and the resistance to 1-arginine, 1-homoarginine, and heat treatment at 56 degrees C for 10 minutes dropped. The activity of the serum alkaline phosphatase with the spontaneously affected calves and cows was dependably lower than the activity of the enzyme un normal calves and cows. It is believed that the drop of the total activity of the blood serum alkaline phosphatase is chiefly governed by the lowered release in the blood of intestinal alkaline phosphatase as the result of its disturbed synthesis and intestinal absorption.