To observe the cardiogenic effects on the mechanism of circulatory shock in acute venom intoxication, a pathological and biochemical studies were carried out in the heart of rats using venom of Agkistrodon b. brevicaudus. The rat used were adults weighing between 200^-250 gm. 44mg, of freeze dried venom was ,diluted to 12 m] of normal saline and 0. 4 ml of this solution was administrated intravenously through the tail vein to each rat.
The rats were sacrificed serially with time interval after venom administration 1 hour, 3 hours, 6 hours, .24 hours, 4 days and 7 days, respectively. The hearts were immediately prepared for light and, electron microscopy. Additionally, serum enzymes such as glutamic oxaloacetic transaminase (GOT) , lactic dehydro-_genase (LDH) and creatinine phosphokinase (CPK) were measures for the correlation.
The results obtained were as follows:
1. Light microscopic changes in the heart revealed moderate to marked congestion, edema´, hemorrhage with coagulation necrosis of myocardial muscles in the ventricular and subendocardial _ myocardium. Infiltration of inflammatory cells in necrotic areas was increased in 6 hours. Later, fibrosis was due in the multiple areas of previous necrotic areas.
2. Early electron microscopic changes in the myocardium revealed marked intracellular edema with lifting, bleb formation and rupture of sarcolemma as well as separation of myofilaments and focal random loss of myofilaments. Mitochondiral swelling and vacuolar changes were also noted.
3. Serum levels of GOT were significantly elevated from 3 hours to 6 hours to 410. 4209. 6IU,/l(p<, 0.01).
.4. Serum levels of LDH were reduced significantly from 6 hours to 24 hours to 372.2238.8 IU/l (p< 0.01).
5. "Serum levels of CPK were reduce significantly in 6 hours to 457.. 1123.21U/1 (p<0.05).
With above results, it was suggested that cardiotoxocity of venom of Agkistrodon b. brevicaudus, characterized by marked myocardial edema and hemorrhage with necrosis, could play a role in explaining acute circulatory collapse in rats after venom intoxication. It was also interesting to note that the ´extent of myocardial damage did not correlated with the levels of serum GOT, LDH, and CPK.
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