ABSTRACT
Snake venom is a complex mixture containing diverse protein components with different structures and functions that are used for prey immobilization and death. Snake venoms from the family Viperidae cause pronounced local and systemic effects, such as pain, edema, hemorrhage and necrosis. Here, we investigated the enzymatic and biological activities of venoms from two Amazonian snakes, Bothriopsis bilineata and Bothriopsis taeniata. Both venoms presented high enzymatic activities for proteases kallikrein, thrombin and plasmin, low levels of trypsin, cathepsin C and leucine aminopeptidase activities, while lacked acetylcholinesterase activity. B. taeniata and B. bilineata crude venoms caused inflammation inducing neutrophil recruitment into peritoneal cavity of mice 4h after injection. Neutrophil recruitment induced by B. taeniata venom was accompanied by hemorrhage. EDTA treatment profoundly impaired neutrophil recruitment, suggesting the involvement of a metalloproteinase on venoms-induced neutrophil recruitment. Pretreatment with dexamethasone and zileuton, a 5-lipoxygenase inhibitor, significantly reduced neutrophil migration, but indomethacin and montelukast, a cysteinyl leukotriene receptor antagonist, had no effect, suggesting the involvement of lipoxygenase-derived metabolites, probably LTB(4). Together, these results show that B. bilineata and B. taeniata venoms induce a marked inflammatory reaction, with leukocyte recruitment, and hemorrhage, which parallels to a high proteolytic activity found in these venoms.
Subject(s)
Bothrops/physiology , Crotalid Venoms/toxicity , Animals , Cell Movement/drug effects , Crotalid Venoms/chemistry , Crotalid Venoms/enzymology , Edetic Acid/pharmacology , Freeze Drying , Inflammation/pathology , Mice , Mice, Inbred C57BL , Neutrophil Infiltration/drug effects , Neutrophils/drug effects , South America , Species SpecificityABSTRACT
Gonadal hormones appear to modulate brain energy metabolism, and morphological and functional sexual differences are found in the amygdaloid complex (AC) of rats. Our aim was to study the CO2 production and lipid synthesis, measured by the rate of L-[U-14C]lactate or D-[U-14C]glucose utilization (in pmol x hr(-1) x mg(-1)), by AC slices in vitro of male and female rats. Lactate was more used than glucose as energy substrate (p < 0.01) but no sex-related difference was observed in glucose or lactate oxidation to CO2 (p > 0.05) or on lipid synthesis obtained from both substrates (p > 0.05). In addition, there was no effect of the estrous cycle on lactate oxidation to CO2 by the AC of females (p > 0.05). Based on the present data, it appears that the endogenous normal levels of gonadal hormones are not able to promote sex-related differences in the in vitro glucose or lactate utilization by the AC of rats.
