Non-ACTH components of adult human pituitary extracts which stimulate adrenal steroidogenesis

Human pituitary extracts were fractionated by chromatography on Sephadex G-50 and G-25, and low molecular weight components were further separated by HPLC. Eluates were tested for their activity in stimulating steroidogenesis in suspensions of rat adrenal capsule (largely zona glomerulosa) and inner zone (fasciculata/reticularis) cells. Several biologically active components were reproducibly isolated. Three stimulated glomerulosa cells specifically, and one of these was tentatively identified by HPLC and RIA criteria as desacetyl-alpha-MSH. Alpha-MSH was not detected. One component stimulated both cell types but two others stimulated inner zone cells, and were without effect on glomerulosa cells: this type of activity has not previously been described, and is not associated with any peptide derived from pro-opiomelanocortin which has so far been tested. The data suggest that, in addition to corticotrophin, further pituitary peptides may be involved in the control of adrenocortical function.