Effect of Acetylcholine on Mammary Gland of the Lactating Sow

Summary Acetylcholine was shown to cause the let-down of milk in the intact lactating sow. The time interval from injection to milk let-down was believed to indicate direct action upon the mammary gland, although action on the pituitary may also occur. The let-down effect was augmented by the anticholine-esterase action of prostigmine. Small amounts of carbaminoylcholine, a derivative, had let-down action similar to acetylcholine.