Saturday, June 18, 2011
Saudi Med J, 2011 Jun;32(6):563-70
OBJECTIVE: To elucidate the possible effects of bee venom (BV) on cardiac electrophysiological properties in vivo, the inotropic and chronotropic properties of the isolated hearts in vitro, and the cardiac responsiveness to progressive adrenergic stimulation by isoproterenol.
METHODS: This randomized control study was conducted in the Physiology Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt, from April to June 2010. This work was carried out on 22 female Wistar rats. Rats were allocated into 2 groups; BV-treated group (rats were treated with BV in a dose of 20 microgram/kg body weight, administered subcutaneously for 4 days), and the control group. Prior to sacrifice, the studied animals underwent electrocardiographic (ECG) assessments under anesthesia. Thereafter, isolated hearts were studied in a Langendorff preparation for their intrinsic properties, and their responses to beta-adrenergic stimulation. Following recovery, heart tissues were used for assessment of myocardial calcium content, and for histological examination.
RESULTS: No abnormal ECG findings were observed in the BV-treated group. The BV treatment enhanced tension generation in the cardiac muscle in response to beta-adrenergic stimulation, and improved the inotropic cardiac reserve. Calcium content of the myocardial tissue of BV-treated group was significantly increased. Histological examination of the cardiac tissue of BV-treated group demonstrated preserved myofilament and mitochondrial ultrastructural integrity.
CONCLUSION: The BV enhanced the cardiac inotropic reserve to beta-receptor agonists. Meanwhile, BV protected the heart against calcium overload-induced injury.