All are functions of oxytocin except

Maintenance of lactation (galactopoiesis) is by prolactin. Oxytocin causes contraction of the myoepithelial cells, smooth muscle-like cells that line the ducts of the breast. This squeezes the milk out of the alveoli of the lactating breast into the large ducts (sinuses) and thence out of the nipple (milk ejection or expulsion of milk or galactokinesis). Oxytocin causes contraction of the smooth muscle of the uterus. Oxytocin may also act on the nonpregnant uterus to facilitate sperm transpo. It causes increased contraction of the smooth muscle of the vas deferens, propelling sperm toward the urethra.