الفهرس Only 14 pages are availabe for public view
 |  | from | 206 |  |  |
| | | from | 206 | | |
Abstract
The present study was performed to evaluate the effectiveness of gamma radiation in detoxification of Echis Coloratus snake venom and its fractions without affecting their immunogenic properties. This was carried out by studying the lethality as well as the immunological, biological, biochemical and histological effects of Echis Coloratus venom at a sublethal dose has been investigated before and after exposure to gamma radiation (1.5KGy and 3KGy). The toxicity of Echis Coloratus venom after (1.5 and 3 KGy) gamma irradiation was reduced; in a way that the LD50 of gamma irradiated (1.5 and 3 KGy) venom was 6.4 and 7.2 times, respectively that of the native venom. SDS{u2013}polyacrylamide gel (15%) electrophoresis of Echis coloratus snake non-irradiated venom and venom irradiated with 1.5, 3, 15 and 30 KGy showed that the venom components were altered after irradiation, some protein bands gradually disappeared and the intensity of bands decreased. The selected dose to carry out venom fractionation was 3 KGy gamma irradiation There was no change in the antigenic reactivity between both native and (1.5 and 3KGy) gamma irradiated venom. The result of double immunodiffusion test of the obtained fractions before and after exposure to 3 KGy gamma irradiation against the commercial polyvalent Egyptian antivenin, showed similar precipitin patterns.The phospholipase A2 activity of irradiated venom at 1.5 and 3 KGy was 1.3 and 2.3 times less than in the native venom, respectively. All fractions showed the PLA2 activity except fractions FN I and FR I. The phospholipase A2 activity of FR II and FR III after exposure to 3 KGy gamma irradiation was less than the corresponding native fractions by 2.8 and 2.4 times, respectively. Also, Proteolytic activity of Echis Coloratus snake venom showed a significance decrease after irradiation. The protease activity of irradiated venom at 1.5 and 3 KGy was 1.7 and 2.4 times less than that of the native venom respectively. The proteolytic activity presented in all fractions except fractions FN III and FR III. The proteolytic activity of FR I and FR II after exposure to 3 KGy gamma irradiation were 2.5 and 2 times less toxic than the corresponding native fractions respectively