Scorpion (Buthus tamulus) venom toxicity on cardiopulmonary reflexes involves kinins via 5-HT3 receptor subtypes
AUTOR(ES)
BAGCHI, S., DESHPANDE, S. B.
FONTE
Journal of Venomous Animals and Toxins
DATA DE PUBLICAÇÃO
2001
RESUMO
The mechanisms underlying the action of Indian red scorpion Buthus tamulus (BT) venom-induced augmentation of cardiopulmonary reflexes elicited by intravenous injection of 5-HT were examined in urethane anaesthetized rats. The 5-HT produced a concentration-dependent increase in time-response area of bradycardiac response, with the responses at submaximal concentrations shifted to the left after exposure to BT venom (20 µg/kg, IV). Aprotinin (6000 kallikrein inactivating unit, IV) as such had no effect on 5-HT reflex responses (bradycardia, hypotension, and apnea), but blocked the venom-induced reflex augmentation. While ondansetron (10 µg/kg, IV) completely blocked the 5-HT reflex responses, these reappeared partially after venom exposure (20 µg/kg). Exposure to bradykinin (50 µg/kg, IV) for 30 min also augmented the 5-HT-induced reflex responses similar to venom. The bradykinin-induced augmentation was also blocked by ondansetron. Results indicate that the venom-induced augmentation of cardiopulmonary reflexes is mediated through kinins sensitizing 5-HT3 receptor subtypes.
Documentos Relacionados
- 5-HT3 receptor channels in dissociated rat superior cervical ganglion neurons.
- Nervous system distribution of the serotonin 5-HT3 receptor mRNA.
- Management of the cardiovascular manifestations of poisoning by the Indian red scorpion (Mesobuthus tamulus)
- Ondansetron, a 5-HT3 antagonist, improves cerebellar tremor.
- Improvements in Hippocampal-Dependent Learning and Decremental Attention in 5-HT3 Receptor Overexpressing Mice