Electrocardiographic (ECG) changes were induced in dogs by injection of scorpion venom from Mesobuthus tamulus concanesis, Pocock. Venom (3 mg/kg body weight) was given subcutaneously (SQ) while 10 ml of scorpion antivenom (SAV) was administered intravenously (IV) to experimental dogs. Group 1 received only the venom; Groups 2, 3, and 4 received SAV at 0, 30, and 60 min, respectively, following envenoming. Thick, ropy and profuse salivation; muscle fasciculation; clonus and tetany-like contractions; frequent urination; and bowel emptying sometimes stained with bile and occasionally blood and bile were observed 20-25 minutes after envenoming. Following envenoming, hyperglycemia, increase in free fatty acid (FFA) levels, and reduction in triglyceride levels were observed in Groups 1, 3, and 4. There was an initial rise in insulin levels at 30 min followed by a reduction at 60 min. SAV caused a subsequent rise in insulin levels but there was a reduction in blood sugar to euglycemia levels and lipogenesis (reduction in FFA and increase in triglycerides levels) in Groups 3 and 4. Abnormal ECG changes and arrhythmias were not observed after SAV. Normal sinus rhythm was restored in Group 4. Scorpion envenoming with multi-system-organ failure (MSOF), characterized by a massive release of counter-regulatory hormones (catecholamines, glucagon, cortisol), angiotensin-II, and changes in insulin secretion, is a condition of fuel-energy deficits and an inability to utilize the existing metabolic substrates. These disturbances are reversed by SAV possibly through insulin release. It is concluded that SAV, under the laboratory conditions, effectively neutralizes, prevents, and reverses scorpion venom toxicity.

Acute myocardiopathy in experimental dogs and rabbits was induced by subcutaneous (SQ) injection of 3.5 mg/kg of scorpion venom from Mesobuthus tamulus concanesis, Pocock. An increase in circulating lactic dehydrogenase (LDH), serum glutamic oxalacetic transaminase (SGOT), creatine kinase-MB isoenzyme (CK-MB), serum glutamine pyrovate transaminase (SGPT) and alpha hydroxy butyrate dehydrogenase (HBDH) enzyme levels was observed in dogs 60 min after venom injection, and a further rise was observed 120 min after venom injection. The administration of the species-specific scorpion antivenom (SAV) at different time intervals after venom injection resulted in reversal of electrocardiographic changes and a reduction in cardiac enzyme levels. The administration of SAV to scorpion envenomed alloxan-pretreated animals did not cause clinical or biochemical improvement. On the other hand, administering insulin to envenomed only animals or envenomed alloxan-pretreated animals resulted in a biochemical and clinical improvement, as well as in a reduction of the cardiac enzyme levels. Insulin administration in scorpion envenoming syndrome is essentially a metabolic support to control the adverse effects triggered by catecholamines and other counter-regulatory hormones.