Coordinate regulation of mRNA levels of pro-opiomelanocortin and the candidate processing enzymes PC2 and PC3, but not furin, in rat pituitary intermediate lobe.

Pro-opiomelanocortin is a multivalent hormone precursor which is processed at pairs of basic residues in a tissue-specific manner to release biologically active peptides. We have examined the message levels of three candidate pro-opiomelanocortin processing enzymes in the intermediate lobe of the rat pituitary following treatment with a dopamine receptor agonist and antagonist which are known to regulate pro-opiomelanocortin mRNA levels. Message levels for PC2 and PC3 but not furin were coordinately regulated with pro-opiomelanocortin transcripts supporting a role for PC2 and PC3 in the maturation of the pro-opiomelanocortin precursor in the rat pituitary intermediate lobe.