REGIONAL DISTINCTION IN AGE-RELATED-CHANGES OF PREOPTIC REGULATORY FACTOR-I AND PREOPTIC REGULATORY FACTOR-II MESSENGER-RNA EXPRESSION IN THE RAT-BRAIN

Preoptic regulatory factor-1 (porf-1) and preoptic regulatory factor-2 (porf-2) are two novel neuropeptide genes expressed in the central ne rvous system and peripheral tissues. Other studies have shown that the se genes may play a role in steroid-dependent brain development and fu nctions. In this study, nuclease protection assays were employed to in vestigate Porf-1 and Porf-2 mRNA expression in male rat brains of diff erent ages. The preoptic area (POA), cerebral cortex (CC), and hippoca mpus (HIPP) expressed both Porf-1 and Porf-2 mRNA, while only Porf-2 m RNA was detectable in the medial basal hypothalamus (MBH). Porf-1 mRNA in the POA was highest at the age of 2 months (young adult), decrease d at the age of 6 months (mature adult), and remained low at the ages of 12 (middle aged) and 24 months (aged). Porf-1 mRNA in the CC was al so the highest at the age of 2 months and decreased with age. However, there were no age-related changes for Porf-1 mRNA in the HIPP. Porf-2 mRNA in the HIPP was found to be low at the age of 2 months, increase d at the ages of 6 and 12 months, and decreased at the age of 24 month s. The effect of age on Porf-2 mRNA in the POA was similar to that see n for Porf-1, with the highest expression observed in the 2-month-old rats. There were no age-related Porf2 mRNA changes in the MBH and CC. These results indicate differential regulation of expression of the po rf-1 and porf-2 genes in the MBH, POA, HIPP, and CC. The possible role s of these two genes in maturation and aging of male rats are discusse d. (C) 1994 Academic Press, Inc.