Cardiovascular profile after intravenous injection of Africanized bee venom in awake rats.

The manifestations caused by Africanized bee stings depend on the sensitivity of the victim and the toxicity of the venom. Previous studies in our laboratory have demonstrated cardiac changes and acute tubular necrosis (ATN) in the kidney of rats inoculated with Africanized bee venom (ABV). The aim of the present study was to evaluate the changes in mean arterial pressure (MAP) and heart rate (HR) over a period of 24 h after intravenous injection of ABV in awake rats. A significant reduction in basal HR as well as in basal MAP occurred immediately after ABV injection in the experimental animals. HR was back to basal level 2 min after ABV injection and remained normal during the time course of the experiment, while MAP returned to basal level 10 min later and remained at this level for the next 5 h. However, MAP presented again a significant reduction by the 7th and 8th h and returned to the basal level by the 24th h. The fall in MAP may contribute to the pathogenesis of ATN observed. The fall in MAP probably is due to several factors, in addition to the cardiac changes already demonstrated, it is possible that the components of the venom themselves or even substances released in the organism play some role in vascular beds.