RESUMO
The state of the serotonergic system was studied in adaptation of rats to short-term non-damaging stress actions along with the possibility of protecting the heart of conscious animals against arrhythmias in acute ischemia with the serotonin analogue 4-nitro-5-methoxytryptamine. It was shown that the adaptation resulted in a significant increase in rat midbrain serotonin by 70%. Preliminary administration of the serotonin analogue 3 fold reduced the total duration of arrhythmias and approximately 5 fold--the heart fibrillation rate and the death rate of animals in acute ischemia. The data obtained are in agreement with the idea on the role of stress-limiting systems in prevention of stress-induced and ischemic damages of the organism. They show that protective effects of metabolites of these systems can be successfully reproduced with their synthetic analogues or activators.
Assuntos
5-Metoxitriptamina/análogos & derivados , Antiarrítmicos/uso terapêutico , Arritmias Cardíacas/prevenção & controle , Infarto do Miocárdio/complicações , Serotonina/análogos & derivados , 5-Metoxitriptamina/uso terapêutico , Animais , Complexos Cardíacos Prematuros/prevenção & controle , Ventrículos do Coração , Masculino , Mesencéfalo/análise , Infarto do Miocárdio/metabolismo , Ratos , Ratos Endogâmicos , Serotonina/análise , Estresse Fisiológico/metabolismo , Taquicardia/prevenção & controle , Fibrilação Ventricular/prevenção & controleRESUMO
In experiments on mice a study was made of different substituents in the 4th position of the indole ring of 5-methoxytryptamines (5-MOT) on toxicity and radioprotective efficiency of the compounds of this class. It was shown that the administration of the amino-group to a mexamine molecule increased the preparation toxicity; the nitro-group somewhat diminished the toxic properties, and the acetylamino group did not change 5-MOT toxicity. A 5-MOT derivative with a nitro group possessed the strongest radioprotective action. The radioprotective efficiency of these compounds persisted for 1-2 h.