Abstract
Hetrazan increases the tone as well as the motility of longitudinal and circular muscles of the isolated small intestine of rabbits in a lower concentration, while in a higher concentration the stimulation is followed by depression. These effects are remained, uninfluenced by atropine and ergotamine, and the actions of acetylcholine and pilocarpine are not affected by hetrazan, but nicotine and MgCl2 antagonize completely the stimulant action of hetrazan, where the dose of MgCl2 does not affect the action of acetylcholine. On the intestine depressed by hetrazan both of these drugs have no effects. Similar effects of hetrazan are also observed in situ where the drugs are applied intravenously and where in other cases they are applied to the mucous or serous membrane. Although. the sectioning of the vagus, the splanchnic nerve and the thoracic cord, and. also the application of atropine cause a scarce effect on the stimulant action of hetrazan, while by the intravenous introduction of nicotine the action of hetrazan is completely suppressed. On the isolated non-pregnant uterus of a rabbit, hetrazan increases its motility which is to be checked by MgCl2, nicotine and a large dose of hetrazan. From these facts it may be concluded that hetrazan acts on the autonomic ganglia just as in the case of nicotine, because these drugs have in common a piperazine nucleus in their chemical structures. In addition hetrazan is found to have also a minor analgesic and antihistaminic action.
