Effect of atropine and methylatropine on human vaginal blood flow, sexual arousal and climax.

No experimental data on the regulatory mechanism of the change in vaginal blood flow occurring at sexual arousal exist. Six women were in a controlled laboratory study given atropine 0.035 mg/kg intravenously. The basal vaginal blood flow was recorded by a heat probe kept at set temperature on the vaginal wall. During sexual stimulation the flow was increased as in women when no drugs are applied and orgasm was unaffected as well. The neurotransmitter has been supposed to be acetylcholine but the present experiments suggest that it is not an atropine sensitive traditional muscarinic transmission. Methylatropine was given in five subjects and neither in these cases any effect on the vaginal vascular response was observed.