M-cholinoreactivity of erythrocytes of non-pregnant and pregnant women evaluated by changes in the rate of erythrocyte agglutination under the influence of acetylcholine.

Acetylcholine (5.5×10(-10)-5.5×10(-6)M) accelerated erythrocyte agglutination in men, non-pregnant women in follicular phase of the menstrual cycle, and pregnant women in the first trimester.