Placental secretion of prolactin, ACTH and immunoreactive beta-endorphin during pregnancy.

The placental secretion of Prl, ACTH and immunoreactive (IR)-beta-endorphin were examined in early and later pregnancy with a perfusion method and by determining tissue concentrations of these hormones. Prl was secreted mainly from decidual tissue during 5-6 h long perfusions. Tissue concentrations of Prl were also significantly higher in decidual than in trophoblastic tissue. In contrast, the tissue concentrations of hCG, hPL, ACTH and IR-beta-endorphin were significantly higher in decidual than in trophoblastic tissues. In contrast, the tissue concentrations of hCG, hPL, ACTH and IR-beta-endorphin were significantly higher in trophoblastic than in decidual tissues. Production of hCG and hPL was predominantly demonstrated in trophoblastic tissues by the perfusion method but ACTH and IR-beta-endorphin were too low to be detected by perfusion.