Prostaglandin administration to pregnant rats: effects on pituitary-target gland systems of mother, fetus and neonate (38512).

Acute administration of PGE-1 in graded doses (0.25-1.0 mg) to pregnant rats in late gestation (21st day) induced significant release of TSH, prolactin and LH from the maternal, pituitary. Plasma levels of PRL and TSH were elevated (three- to fivefold) in cesarean sectioned mothers given 4-5 sc injections of PGE-1; higher doses also stimulated LH release. Comparable increases in blood TSH and PRL levels were also found in their newborn but no indication of enhanced hormone release from the fetal hypophysis was noted. Histologic alterations were observed in the ovary (luteal cell hypertrophy, cytopasmic clearing, nuclear condensation, sinusoidal distension) of mothers receiving PGE-1 treatment. Thyroidal radioiodine accumulation in mother, fetus and neonate were usually decreased whereas thyroid: blood radioactivity ratios were consistently incrased. It is concluded that PGE-1 treatment of th pregnant rat near term stimulates release of hormones from the pituitary in mothers (TSH, LH, PRL) and in their newborn (TSH, PRL). The results also strongly suggest that PGE-1 administration may induce morphologic and functional changes in target endocrines (ovary, thyroid) by direct and separate actions.