EFFECTS OF PEPTIDES OF PITUITARY ORIGIN ON FORMATION OF C21 STEROID BY FETAL CALF ADRENAL-CELLS IN CULTURE

Corticotrophic activity of opiate-like peptides was assessed by their ability to stimulate the formation of C21 steroids from [3H] progesterone by 3 day old cultures of fetal calf adrenal cells. ACTH1-39, ACTH.alpha.1-24 and a purified preparation of pituitary ovine .beta.-endorphin caused a marked increase in 17.alpha. and 21-hydroxylation, while a preparation of pure synthetic porcine .beta.-endorphin gave a minimal stimulation. The activity of the purified ovine .beta.-endorphin preparation was not accounted for by contamination by ACTH or by a synergistic action between the 2 peptides. The novel pituitary factor described here may be due to a contaminant of the .beta.-endorphin peak which was different from ACTH1-39.