[An experimental study of the role of prostaglandins in the mechanism of the occurrence of dyspeptic disorders during the primary reaction after body exposure to ionizing radiation at large doses]. / Eksperimental'noe izuchenie roli prostaglandinov v mekhanizme vozniknoveniia dispepticheskikh narushenii v period pervichnoi reaktsii posle vozdeistviia na organizm ioniziruiushchikh izluchenii v bol'shikh dozakh.

The experiments with dogs exposed to 100 Gy of accelerated electrons demonstrated a significant role of prostaglandins in the origin of early post-radiation dyspepsia. Their significance for genesis of post-radiation dyspeptic disturbance caused by exposure to superhigh doses becomes clear-cut when a combination of an antiemetic and inhibitors of prostaglandin biosynthesis is used. A study of the effect of dexamethasone, a blocker of arachidonic acid release, and of voltaren, an inhibitor of prostaglandin formation from cyclic endoperoxide, suggests that it would be appropriate to prevent radiation vomiting and diarrhea by inhibiting both of the above stages in prostaglandin biosynthesis.

[An experimental study of the role of a blockade of serotonin 5-HT3 receptors and dopamine D2 receptors in the mechanism of the occurrence of early radiation vomiting in monkeys]. / Eksperimental'noe izuchenie roli blokady 5-HT3-retseptorov serotonina i D2-retseptorov dofamina v mekhanizme vozniknoveniia rannei radiatsionnoi rvoty u obez'ian.

The experiments with M. fasciculata monkeys exposed to 137Cs gamma-radiation with a dose of 6.9 Gy showed that Latranum, a blocker of serotonin 5-HT3 receptors, is a more efficient antiemetic than Dimetphramidum, a D2 dophamin lytic. This is suggested by fewer animals with emetic reaction of by less severe vomiting in case they have any. The results agree well with a hypothesis that serotonin receptors are dominant in the chemoreceptor trigger zone of monkeys.

[The mechanism of the occurrence of vomiting during the primary reaction after exposure of the body to ionizing radiations at large doses]. / O mekhanizme vozniknoveniia rvoty v periode pervichnoi reaktsii posle vozdeistviia na organizm ioniziruiushchakh izluchenii v bol'shakh dozakh.

In the experiments of dogs exposed to ionizing radiations at doses of 50 and 70 Gy, an essential role of the central mechanism in the origin of early postradiation vomiting has been confirmed. Insufficient efficiency of dimethpramide, a dophamynolytics, in this case may be connected either with initiation of other (non-dophamynosensitive) structures of the chemoreceptor trigger zone of with a growing role of the reflex way of vomiting arising due to a considerable intestinal injury that causes diarrhea. The inhibition of intestinal M-cholinoreceptors by methacine prevented diarrhea but didn't change the intensity of the vomiting reaction which, however, does not eliminate the possibility of afferentation from receptors that respond to others biologically active substances.

[Antiemetic activity of dimetpramid]. / Issledovanie protivorvotnoi aktivnosti dimetpramida.

It has been shown that dimethpramide, a new Soviet-made antiemetic belonging to the group of substituted benzamides, effectively prevents the emetic action of L-DOPA and apomorphine in dogs (the ED50 is 0.04 and 0.12 mg/kg, respectively). When given in doses of 10-25 mg/kg dimethpramide suppresses vomiting induced by adrenaline, histamine, strophanthine, sodium salicylate, and copper sulfate. The drug exerts a selective dopamine-blocking action on the receptors of the triggering zone of the vomiting center without producing any substantial action on the dopaminergic brain systems that regulate behavioral activity.