Studies of the thyrotropic function of the adenopituitary of the offspring of rats treated during pregnancy with dopaminergic agents.

The thyrotropic function of the adenopituitary of rats, which were the offspring of animals treated during pregnancy with L-DOPA, bromocriptine and haloperidol, was studied. The agents were administered according to a schedule between the 1st and the 20th day of gestation--orally for L-DOPA and bromocriptine, and intramuscularly for haloperidol--on 3-month old pregnant Wistar rats. The studies on the thyrotropic function of the pituitary were carried out on the offspring of male rats reaching sexual maturity at the age of three months at a temperature of 20 +/- 2 degrees C and with cold treatment for 60 min at 4 degrees C. The content of the thyrotrophic hormone (TTH) was determined radioimmunologically in the animals' serum. A statistically significant decrease of the basic and cold-stimulated TTH-content was observed in the serum of the offspring of rats treated during pregnancy with L-DOPA (200 mg/kg body mass) and an increase in the basic TTH content after prenatal treatment with haloperidol in doses of 1 mg/kg body mass. No statistically significant differences were found in the TTH-content in the two experimental setups, after prenatal application of bromocriptine in doses of 1 mg/kg. The effect of the dopaminergic agents applied prenatally on the development of the central neuro-regulatory mechanism, which play a role in the regulation of the TTH secretion, is discussed.