Immunohistochemical investigation of neuronal injury in cerebral cortex of cobra-envenomed rats

The immunohistochemical expression of neuron-specific enolase, NSE (a cytoplasmic glycolytic enzyme of the neurons), synaptophysin, SYN (a major membrane glycoprotein of synaptic vesicles), and Bcl-2 (anti-apoptotic protein) were determined in cerebral cortex of rats envenomed with neurotoxic venom from Egyptian cobra. Male rats were intramuscularly (IM) injected with a single injection of either physiological saline solution or ½ LD50 or LD50 of cobra venom and sacrificed 24, 48, or 72 hr after envenoming. Formalin-fixed paraffin sections were immunohistochemically studied by avidin-biotin-peroxidase complex method. Neuron histological structure and isolation of genomic DNA were also detected. The results showed a dose and time-dependent increase in NSE and SYN immunoreactivity in cerebral cortex of envenomed rats except in 72 hr high dose envenoming, where decreased SYN was observed. On the other hand, low dose venom induced high Bcl-2 expression 24 hr after envenoming, while the high dose decreased Bcl-2 protein expression. Temporal and spatial Bcl-2 expression was accompanied by DNA fragmentation in cerebral cortex of all envenomed rats, although no serious histological alterations were noticed. These results suggest that cobra venom may lead to neuronal injury and impairment of axonal transport as ascertained by alterations in NSE and SYN immunoreactivity. It could also indicate that venom alters the molecular machinery of apoptosis by inhibiting Bcl-2 expression; however, some vulnerable cells have the ability to overcome this by increasing Bcl-2 protein. These immunohistochemical investigations can be used as tools for detecting neuronal abnormalities even before the occurrence of any histological alterations in case of cerebral cortex neurotoxicity

Perfil bioquímico sorológico de bovinos inoculados experimentalmente com veneno crotálico iodado livre e iodado incorporado em liposomas Serological biochemical profile of bovines poisoned experimentally with free iodized crotalic poison and iodized incorporated in lipossomes

Investigou-se o perfil sorológico de bovinos inoculados com veneno crotálico detoxificado pelo método de iodação e iodação com encapsulação em liposomas. Onze fêmeas com idade média de 18 meses e peso médio de160kg, foram inoculadas com 0,03mg/kg de peso vivo do veneno crotálico do tipo crotamina positivo. Cinco animais receberam o veneno iodado livre, cinco o iodado encapsulado em liposomas e um animal recebeu o mesmo veneno na forma natural, para controle da letalidade da amostra de veneno utilizada. Não houve alterações significativas na concentração de proteínas totais, uréia e creatinina em ambos os tratamentos. Foi observada diferença significativa na concentração de creatinafosfoquinase a partir de duas horas após a inoculação do veneno. A iodação do veneno crotálico, com ou sem incorporação em liposomas, suprimiu seus efeitos deletérios sobre o perfil bioquímico de bovinos.<br>It was studied the activity of the Crotalus venom detoxified encapsulated in lipossomes or non-encapsulated by the method of controlled iodination on the biochemical profile of bovines. Eleven 18-months-old female bovines, weighting 160kg in average were used in this study. Groups of five animals were inoculated intramuscularly with a dose of 0,03mg/kg with either the detoxified non-encapsulated venom or the detoxified encapsulated venom. One control animal received the same dose of non detoxified venom by the same route. No significant differences were observed between the study groups for the parameters of total protein, urea and creatinine. Differences were observed for creatine phosfokinase at times T O and T12 for the group treated with the iodinated venom encapsulated in liposomes. The detoxification process abolished the activity of the venom in the encapsulated or nonencapsulated form on the biochemical parameters and renal activity of bovine