DIFFERENTIAL-EFFECTS OF ACTH-RELATED PEPTIDES AND FORSKOLIN ON RAT SCHWANN-CELL PROLIFERATION AND LOW-AFFINITY NGF RECEPTOR EXPRESSION

We investigated the effect of the neurotrophic peptides alpha MSH and Org 2766 on Schwann cell proliferation (BrdU incorporation) and low af finity nerve growth factor receptor (LNGFR) expression in vitro. Cells were cultured under four conditions: low or high density culture, wit h forskolin present or absent in the medium during one week before sta rt of the experiment. Schwann cells were treated with alpha MSH, Org 2 766 or forskolin. After 48h forskolin (10 mu M) increased BrdU incorpo ration (32-151%) in all culture conditions and LNGFR production (25-19 4%) in 3 out of 4 conditions. alpha MSH and Org 2766 had no effect. Th is study shows that Schwann cell proliferation and LNGFR expression is under control of cAMP. Furthermore, the neurotrophic effect of alpha MSH and Org 2766 is probably not mediated through an increased cell di vision or LNGFR expression in Schwann cells.