فهرست مطالب نیلوفر سیدیان

Hemiscorpius lepturus belonging to Hemiscorpiidae family is the most venomous of all types of scorpion existing in south west of Iran causing hemoglobinuria and dermal lesions by envenomation. We compare the hemolytic pattern upon time in different domestic animals upon time according to their different sphingomyelin contents. In addition other in vitro hematologic parameters، platelet lysis، coagulation changes and finally preservative factors (temperature، pH، protases) are discussed. The hemolytic activity was inhibited significantly by heating at 100 °C for 60 minutes (26%) and reached 38% via incubation with papain (10U/ml) while retained over a pH range of 4-11. Horses and sheep have the lower (61%) and upper (100%) rate of hemolysis. Calcium and magnesium ions could increase rate of hemolysis and EDTA solution had significantly decresing effect. The venom significantly changed in vitro coagulation factors (PT and APTT) from base line levels and had no effect on platelet lysis. It seems that our venom belongs to metalloproteinases due to potentiation effects of bivalent cations (calcium and magnesium) and ghost cell formation in our study indicatiing hemoglobin efflux.

The hemotoxic and neurotoxic factors of snake venoms is the main responsible for necrosis and tissue sloughing. Envenomations are common in rural areas in all provinces of Iran caused by snake species which causes local swelling، ecchymosis and alterations in blood profile in case of hemotoxic venom. In this study some in vivo and in vitro properties (Hemorrhagic، edematogenic and coagualant) of Iranian Vipera lebetina venom in addition to neutralizing capacity of pepsin derived Razi Institute polyvalent antivenin were assayed. Escalating doses of Vipera lebetina venom dissolved in Normal saline (2. 5-50 µg/ml) were injected (100µl) subcutaneously to dorsal area of rats (n=3) to investigate mean hemorrhagic amount after 24 hours. Groups of three mice were injected subcutaneously in the right foodpad with various amounts of venom (10-150µg). The left foodpad received the same amount (100µl) ofnormal saline alone (negative control) to evaluate the edematogenic property of this venom. To determine the coagulant activity، various amounts of venom dissolved in normal saline (50µl) were added to human plasma (200µl) and coagulation time was measured. Razi Institute antivenom was used for neutralization of all three measured biological parameters. Mean hemorrhagic، procoagulant and edematous amounts (increasing 30% in hind paw edema) were 8. 5، 1. 1 and 70 microgram، respectively. Preincubation with polyvalent antibody (30 and 200 microliter) decreased hemorrhagic and procoagulant activity. Edematogenic property of this venom decreased significantly by incubation with antivenom (78% to 38% by incubation with 1000 microliter of polyvalent antivenom). Intra peritoneal injection of this remedy following envenomation had no effect in relieving symptoms. Myonecrotic effects were seen by intramuscular injection of Vipera lebetina venom in rats. Our study shows that Iranian antivenom could neutralize some in vivo and in vitro hazardous effects of envenomation by this snake like hemorrhagic، edematogenic and procoagulant properties that paves the way for separation and purification of multiple enzymes present in this venom to investigate the neutralizing capacity from Razi Institute polyvalent antivenom.