The effects of synthetic corticotropin-releasing factor (CRF) and dopamine on immunoreactive β-endorphin/β-lipotropin (iβ-END/LPH) and aMSH release were studied in superfused human fetal pituitary glands. CRF (20 ng) stimulated the release of iβ-END/LPH in four anterior hemipituitaries from fetuses older than 20 weeks in gestation. There was no effect on three anterior hemipituitaries from fetuses of 19–20 weeks gestation. CRF had no effect on iβ-END/LPH or αMSH secretion from neurointermediate lobes regardless of fetal age. Dopamine (10−6 M) had no effect on iβ-END/LPH or αMSH secretion from either anterior or neurointermediate lobes. The data suggest that anterior pituitary responsiveness to CRF develops at about 20 weeks gestation and that fetal neurointermediate lobe secretion of peptides is not regulated by CRF.
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Clinical Biochemistry
- Biochemistry, medical