[respiratory responses to microinjections of bombesin into the solitary tract nucleus, and the mechanism of their realization].

We investigated the respiratory effects of 10-(13)-10(-4) M bombesin microinjected into the solitary tract nucleus of adult anaesthetized rats. Bombesin markedly increased ventilation, tidal volume and electric activity of inspiratory muscles. The respiratory response was most pronounced when bombesin administered in mean concentrations (10(-10)-10(-7) M). We found that the respiratory effects ofbombesin could be based on its capacity for inhibition of Hering-Breuer inspiratory termination reflex at the level of the solitary tract nucleus. These results in aggregate with pattern of the distribution of endogenous bombesin and its receptors in the solitary tract nucleus area suggest the involvement of bombesin in the respiratory control via dorsal structures of the respiratory center.