Pharmacologic analysis of the mechanism of development of serotonin diarrhea in the mouse

: Diarrhea that arises in mice given serotonin intravenously is not suppressed by tipindolol, LSD-25, ciproheptadine in doses in which these drugs block the D and T serotonin-reactive structures, or is not reduced by hexonium, thereby providing no evidence in favour of the reflex nature of the effect. Diarrhea is suppressed by morphine and atropine, thus pointing to the responsibility for its origin of M-serotoninoreactive structures of intestinal parasympathetic ganglia with subsequent involvement of the postganglionic cholinergic link.