Study of patient's injuries by stingrays, lethal activity determination and cardiac effects induced by Himantura gerrardi venom

Stingrays are common inhabitants in the northern waters of the Persian Gulf and Oman Sea. In the present study, the clinical aspects of injuries induced in three patients bitten by stingrays in Hormozgan province waters were first examined. The LD50 of crude venom extract obtained from the most common stingray in Hormozgan province (Himantura gerrardi) was then estimated by up-and-down dosing and double dose methods in mice. Third and finally, the cardiac symptoms induced by injection of the extract from the venomous spines were evaluated in rats. Intense pain was noticed in all human cases. Redness was observed in two cases, and spasm and seizure were each recorded in only one case. LD50 of the venom extract in mice was about 100 mg kg−1. The observed cardiac symptoms in rats included an increase in pulse rate and various changes in electrocardiogram (ECG) parameters such as T and Q values, and PR and RR intervals.