The effect of Echis carinatus crude venom and purified protein fractions on carbohydrate metabolism in rats

Abstract

Echis carinatus crude venom was fractionated into 11 protein fractions by preparative native polyacrylamide gel electrophoresis (PAGE). All fractions except fractions 5 and 10 appeared as a single band on analytical native PAGE. Purified venom fractions 1, 4, 8, 10 and 11 appeared as single bands on SDS-PAGE whereas fractions 2, 3 and 7 contained two bands and fraction 6 contained three bands. Fractions 1 and 3 exhibited basic pI (7.3 and 7.6) respectively, while fractions 2, 4, 6, 8, 10 and 11 showed an acidic pI. Amino acid analysis also showed that crude venom is rich in acidic amino acids. A significant hyperglycaemia was produced by i.p. injection of E. carinatus crude venom, after 15 min of envenomation which persisted even after 24 h. Along with hyperglycaemia there was a significant decrease of liver glycogen at 15 min and 1, 12 and 24 h. A significant decrease of plasma [pyr + lac] levels was found from 15 min to 24 h. The liver [pyr + lac] levels increased significantly after 24 h. Skeletal muscle [pyr + lac] level was significantly decreased after 24 h of envenomation. Fractions 2 and 6 produced the highest increase in plasma glucose after 12 h and fraction 7 after 24 h. The plasma insulin level was significantly decreased by these three fractions (2, 6 and 7). So it can be hypothesized that the hyperglycaemia may result from a direct effect of a venom component on plasma insulin. Fractions 7, 8 and 11 caused the highest decrease in plasma [pyr + lac] while fractions 1, 2, 3, 4 and 8 produced the most significant decrease in liver [pyr + lac]. The most significant increase in lactate dehydrogenase level was also produced by fractions 1, 2, 3, 4 and 8. Copyright © 2001 John Wiley & Sons, Ltd.