Synthetic modified N-POMC(1-28) controls in vivo proliferation and blocks apoptosis in rat adrenal cortex.

The identity of the pro-opiomelanocortin (POMC)-derived mitogen in the adrenal cortex has been historically controversial. We have used well-established in vivo models, viz., hypophysectomized (Hyp) or dexamethasone (Dex)-treated rats, to study the effect of the synthetic modified peptide N-terminal POMC (N-POMC(1-28)) on DNA synthesis in the adrenal cortex, as assessed by BrdU incorporation and compared with adrenocorticotropic hormone (ACTH).

Distribution of cells expressing Jun and Fos proteins and synthesizing DNA in the adrenal cortex of hypophysectomized rats: regulation by ACTH and FGF2.

Protein expression of the early response genes, jun and fos, has been suggested to play an important role in the in vitro and in vivo proliferation of adrenal cells. To elucidate the immunolocalization of proliferative cells and the patterns of adrenal gland expression of members of the activating protein-1 (AP-1) family of oncogenes, we used hypophysectomized rats. The effects of adrenocorticotropic hormone (ACTH) and fibroblast growth factor 2 (FGF2) on Fos and Jun protein expression were investigated, and DNA synthesis was assessed by using bromodeoxyuridine (BrdU) incorporation.