In vitro response of relaxin-treated rat uterus to prostaglandins and oxytocin.

Paired segments of rat uterus were treated in vitro with relaxin (W1164-3, 150 GPU/mg) until the amplitude of contraction was reduced to at least 50% of the pre-treatment amplitude. Test segments then received 100 ng of either PGE1, PGE2, PGF2alpha or 250 uU of oxytocin. Control segments remained untreated. There was a significant increase in contraction amplitude in response to the spasmogens (P less than 0.05) but no increase was seen in controls.