Sex-related differences in toxic manifestations induced by Bothrops atrox venom in mice.

Lancehead snakes of the genus Bothrops are responsible for 90% of the snakebites in Latin America. The objective of this study was to assess the LD 50 , physical, and hematological manifestations induced by B. atrox venom in male and female mice inoculated by different routes. B. atrox venom was inoculated in male and female mice by intramuscular (IM), subcutaneous (SC), intravenous (IV), and intraperitoneal (IP) routes. B. atrox venom LD 50 was lower in male than female groups, regardless of the injection route. However, it was the lowest when the venom was inoculated by the IP route. Moreover, comparisons between male and female responses according to the injected venom dose showed higher edema-forming, local hemorrhagic, dermonecrotic, and myotoxic activities in male than in female mice. While the minimal hemorrhagic, and necrotic doses were not statistically different between the two groups, the difference between males and females was more pronounced at high venom doses. Hematological parameter changes were also more significant in male than in female mice. The venom decreased the levels of total leukocytes after 24 h of injection in male and female mice, with a more profound decrease in the male group. The micronucleus test, a tool for genotoxicity assessment, documented the mutagenic effects of B. atrox on leucocytes. We demonstrate the higher susceptibility of male mice to B. atrox venom than females. Sex differences must be considered when conducting experimental studies on snake venoms.