Effects of cerastes cerastes cerastes and cerastes vipera venoms on some hormonal levels in the white rat

ABSTRACT

Viprine venoms have drastic effects on the metabolic performance of their victims. The venoms of these two vipers, Certastes cerastes cerastes [C.c.cerastes] and Cerastes vipera [C. vipera] were studied in a comparative manner focusing on some hormones related to glucose level in the blood. Both studies, in vivo and in vitro, were conducted to pinpoint the site and mechanism of action. Levels of insulin, epinephrine, norepinephrine and corticosterone significantly changed by venom injection and by perifusing isolated pancreatic islets with crude venoms. This study primarily concluded that venom of C.c.cerastes has a peptide of hypoglycemic effect. Besides, this peptide may have enough amino acid sequence to bind to anti-insulin antibodies. Venom was milked from C.c.cerastes and C.vipera reared in the serpentarium of the department. White adult male albino rats were purchased and kept in the animal house for acclimatization before experimentation. Radioimmunoassay [RIA] and spectroflourometry were used for hormonal estimation. In vitro study included isolating the pancreatic islets of Langerhans, testing their viability and testing direct effect of the venom on insulin release. While C.c.cerastes venom is hyperinsulinemic and hypoglycemic C. vipera is just the opposite. The two venoms do not adopt opposite mechanisms to effect their roles. Cc. cerastes venom includes apeptide of hypoglycemic effect, it also binds to anti-insulin antibody. Crude venoms of C.c.cerastes and C. vipera are crowds of different peptides. These peptides manifest various effects by working directly on the relevant site or by being a step in a cascade of events. These venoms showed major effects on the blood levels of insulin, epinephrine, norepinephrine and corticosterone. Furthermore, the insulinic effect shown is largely due to a peptide that mimics insulin in its activity. We concluded the presence of a hypoglycemic peptide in the venom of C.c.cerastes that demands further study and characterization