A study of the effects of 8-lysine vasopressin (LVP) and its long-acting analog N-.alpha.-triglycyl-8-lysine vasopressin (TGVP) on the myometrium and vasculature of the normal human nonpregnant uterus was undertaken. The vasopressins decrease local endometrial blood flow both directly by effects on the uterine vascular bed, and indirectly by increasing myometrial activity. The effects in vivo can be effectively counteracted by .beta.2 receptor stimulation.