Synergistic effect of human relaxin and progesterone on human myometrial contractions.

In an in vitro human myometrial strip system, both relaxin and progesterone can independently decrease the amplitude of spontaneous myometrial contractions. However, progesterone and relaxin synergize in this action. Doses of relaxin and progesterone which independently are ineffective, together inhibit myometrial contraction amplitude.

Myometrial inhibiting activity of relaxin-containing extracts of human corpora lutea of pregnancy.

Relaxin is a peptide hormone secreted by the human corpus luteum of pregnancy . Aqueous extracts of relaxin-rich pregnancy corpora lutea decreased the amplitude of spontaneous human myometrial strip contractions in vitro. Relaxin-poor extracts of menstrual cycle corpora lutea did not affect contractions.

Iatrogenic endometriosis: substantiation of the Sampson hypothesis.

A 31-year-old woman developed unilateral endometriosis at the site of ovarian implantation to a uterine window. This complication of the Estes procedure resembles the experimental endometriosis induced in rhesus monkeys by causing intraabdominal menstruation. This adds support to the Sampson hypothesis of endometriosis development.

Serial relaxin concentrations in human pregnancy.

Relaxin is a peptide hormone produced by the corpus luteum during pregnancy in human beings. There are no extraluteal sites of production of relaxin in women. By means of a heterologous porcine radioimmunoassay, serial serum relaxin concentrations were determined in three women throughout pregnancy and into labor.