Hemodynamic Changes Provoked through Intravascular Injection of the Echis carinatus Venom in Rats

Echis carinatus (E. carinatus) is known for its hematological and nephrotoxic properties in the envenomed patients. Based on the limited data upon the cardiovascular changes associated with this dangerous venomous snake in Iran, the current study purposed to evaluate the venom-induced hemodynamic manifestations in rats. Venom (120 µg/kg) was administered intravenously within one minute through the left femoral vein, and the hemodynamic parameters were continuously recorded using a pressure transducer (MLT844, ADInstruments, Australia). The venom caused prominent hypotension leading to death a few minutes after a transient uprise in blood pressure. It also induced a decrease in heart and pulmonary rates, yet it had no arrhythmogenic properties. Additionally, pre-treatment with the pepsin-derived Iranian polyvalent antivenom (30 µl/Kg) completely neutralized the hemodynamic responses but had no effect when instilled two minutes after venom injection. Heparin (300 IU/kg) and epinephrine (1.5 µg/kg) prevented dramatic hypotension when used 10 minutes before venom instillation; however, atropine (1 mg/kg), dexamethasone (1 mg/kg), and ketorolac (10 mg/ml) had no effects. All treated rats were killed post-injection. Histologically, the lung was the most vulnerable organ with mononuclear infiltration, microcystic formation, and significant capillary congestion. Prominent renal pathological deterioration also occurred, including mesangial cell infiltration and diffuse bleeding, leading to acute tubular necrosis. Modest portal inflammation and vascular congestion were observed in the hepatic tissue of the envenomed rats. The crude venom of Iranian Echis carinatus caused hypotension leading to bradycardia, a decrease in pulmonary rate, and death without significant histological changes to the heart.