Enzymes and toxins in scorpions of Buthidae family Insulin-Glucose Administration reverses metabolic, cardiovascular, ECG Changes and pulmonary oedema in scorpion envenoming syndrome

Death due to scorpion stings is a common event in many countries. Scorpion envenoming syndrome consists of the clinical presentation of pain at the site of sting, nausea, vomiting, sialorrhea, profuse sweating, abdominal pain, tremors, arrhythmias, hypertension, agitation, hyperglycemia, restlessness, prostration, priapism, pulmonary oedema, many other manifestations and may concern the CNS, the autonomous system, the respiratory tract, the pancreas, the cardiovascular system. Scorpion venom consists of a mixture of many pharmacologically active enzymes like phospholipase, hyaluronidase, proteinase, peptidase, urease, gelatinolytic and thrombin-like activities. Scorpion venoms contain free amino acids, histamine, serotonin, tryptamine, glycosaminoglycans, chondroitin sulphate and hyaluronic acid. It has neuropeptides, which target ion channels. Tityustoxin, noxiustoxin, Charybdotoxin, “Pulmonary oedema producing toxin” are observed in many of the scorpion venoms. In spite of zoological differences among dangerous scorpion species having many enzymes and toxins with differences in their chemical structure, symptomatology and clinical signs following Buthidae scorpion stings is quite similar. Scorpion envenoming syndrome results in an autonomic storm, massive release of catecholamines, increased levels of angiotensin II, glucagon, Cortisol, suppressed insulin levels/ hyperinsulinemia, glycogenolysis – hyperglycemia and increased free fatty acid levels (FFA). FFA increase the oxygen consumption, aggravate the ischemic injury to myocardium predisposing to arrhythmias, increase the susceptibility of the ventricles to the disorganized electrical behavior, and produce acute myocarditis, cardiac sarcolemmal defects, Disseminated Intravascular Coagulation (DIC) and many other abnormalities. Under these altered hormonal and metabolic conditions, scorpion envenoming syndrome cause Multi-System-Organ-Failure (MSOF) and death. Thus, scorpion envenoming is a syndrome of fuel – energy deficits and an inability to use the existing metabolic substrates by vital organs causing MSOF and death. Insulin administration reversed the metabolic, ECG and cardiovascular changes and pulmonary oedema in the scorpion sting victims. Insulin has a primary metabolic role in preventing, counter-acting and reversing all the deleterious effects of FFA by inhibiting the catecholamine induced lipolysis, increase intra-cellular K + , facilitating glucose transport to the myocardium and glucose metabolism through different pathways. Continuous infusion of regular crystalline insulin should be given at the rate of 0.3 U/g glucose and glucose at the rate of 0.1 g/kg body weight/hour, for 48 72 hours, with supplementation of potassium as needed and maintenance of fluid, electrolytes and acid-base balance. Administration of insulin-glucose infusion to scorpion sting victims appears to be the physiological basis for the control of the metabolic response when that has become a determinant to survival.