[The role of serotonin and histamine in the neurohumoral mechanisms of postirradiation diarrhea in rats].

In experiments with rats exposed to 200 Gy radiation it was shown that the diarrhea effect of serotonin under the effect of radiation is implemented via D- and M-type receptors, and that of histamine via H1 and H2 receptors. Serotonin and histamine, that were released under the effect of radiation from endocrine and mast cells of the digestive tract, stimulated the propulsion activity of the intestine whereas histamine, in addition, inhibited the absorption process. It is suggested that serotonin and histamine antagonists should be used as means of preventing of radiation-induced diarrhea.

[The role of biogenic amines in the neurohumoral mechanisms of postradiation gastrostasis in rats].

In experiments with rats it was shown that pharmacological substances that deplete the biogenic amine pool or selectively arrest dopamine and serotonin receptors prevent or considerably reduce the postirradiation gastrostasis. It is suggested that activation of dopamine- and serotonergic inhibiting mechanisms of regulation of motor-evacuative function of the stomach is responsible for the postirradiation delay in gastric evacuation.