RESUMEN
Six mongrel dogs were subjected to haemorragic shock gy lowering systolic arterial tensien from 120-130 mmHg to 50 mmHg. Their heart and lungs were studied histoachemically after three hours of hypotention and compaired with two control animals. The myocardium showed diminished acid phosphatase activity, the enzyme being liberated from the disrupted lysosomes and esaping from the cells. Lysosomal discruption liberates lysosomal hydrolytic enzymes causing cell damage with escape of cell constituents. Lactic dehydrogenase activity was supposed to increase to cope with increased latic acid production but it was diminished owing to its escape from myocardial cells. Nonspecific esterase showed no change in activity probably due to its increased activity being balanced by its escape from the cells. Its activity probably is related to the change in substrate utilization by the hypoxic myocardium. Alkaline phophatase activity increased denoting enhancenment of transfer across capinary endothelium. The same explanation are true regarding the lung, but being more tolerant to hypoxia, these enzymes did not escape from the cells by the end of the experiment thus showing increased intracellular activity