Estudos das alterações renais e vasculares induzidos pelo veneno e frações isoladas de abelha Apis mellifera

Abstract

The increase in accidents involving Africanized bees in Brazil and throughout Latin America in recent decades has become the object of surveillance by the health authorities, because of accidents with hundreds of bees to be associated with frames of poisoning. The venom of the honeybee Apis mellifera is a mixture of toxic peptides with various local and systemic actions. The objective of this study was to evaluate the renal and vascular changes promoted by the whole venom of the bee A. mellifera and its fractions PLA2 and melittin. Male Wistar rats (250-300g) whose kidneys were isolated and perfused with Krebs-Henseleit solution containing modified 6g% bovine albumin previously dialyzed. The evaluation of the vascular effects of the venom of Apis mellifera in pots was carried out using conductance tests ring of isolated rat aorta. The results showed that the whole venom of A. mellifera and the complexed fraction (PLA2+melittin) promoted significant changes in all renal parameters studied, producing an increase in renal perfusion pressure (PP), renal vascular resistance (RVR), urinary flow (FU) and the glomerular filtration rate (GFR), all these changes were seen at concentrations of 3μg/mL and 10μg/mL. However, the lower concentration (1μg/mL) had no effect on the evaluated parameters. It was observed a significant reduction in the percentage of tubular transport of sodium (Na+), potassium (K+) and chloride (Cl-), suggesting that the whole venom and the fraction complexed (PLA2+melittin) engaged on the renal tubular injury. Were also observed in protein deposition in the renal tubules histological focal regions with necrosis/apoptosis, and was found reduced the viability of the MDCK cells and an increased of the enzyme lactate dehydrogenase (LDH), whose concentration dependent cytotoxic effect with a value IC50 47.84μg/mL. In this sense, the results suggest that the renal lesions were necrosis in the tested conditions. It had been shown in the protocol of aortic ring an increase in contractility. In conclusion, the whole venom and the fraction complexed (PLA2+melittin) of bee Apis mellifera caused nephrotoxicity, suggesting a direct action on cell death in renal tubule cells by necrosis. The contractile effect of bee venom involves the opening of calcium channels operated by voltage and suggest a role of alpha adrenergic receptors via activation of phospholipase C. This finding confirms the results found in the isolated rat kidney and there was an increase in pressure due to renal perfussão possible vasoconstriction of the vessels supplying the kidney. Studies of the venom and its fractions in different systems provide a greater understanding of the pathophysiology and an elucidation of the mechanisms observed. Thus, it can lead to the discovery of pharmacological tools and bioprospecting in the components present in the venom.