Regional processing of the N- and C-terminal domains of proopiomelanocortin in monkey pituitary and brain

The total content and extent of processing of the [gamma]3MSH and [beta]-endorphin-containing N- and C-terminal domains of proopiomelanocortin were determined in the anterior and intermediate lobes of the pituitaries and in 11 regions of the brains of three Rhesus monkeys. Most immunoreactive [gamma]3MSH and [beta]-endorphin was located in the pituitary lobes, although significant amounts were also found in several brain regions. Sephadex column chromatography revealed that [gamma]3MSH immunoreactivity was found primarily as 4K and 9K forms; no [gamma]1MSH was detected. [beta]-Endorphin immunoreactivity was found as [beta]-endorphin, [beta]-lipotropin, and as a 5K form which may represent [beta]-endorphin extended N-terminally by part or all of [beta]-MSH. In the anterior lobe of the pituitary, the predominant products were 9K [gamma]3MSH and [beta]-lipotropin; in the intermediate lobe, more processed forms (4K [gamma]3MSH, [beta]-endorphin and 5K [beta]-endorphin) appeared to be preferentially stored. The pattern of processing in various brain regions was similar to that of the intermediate lobe of the pituitary.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27343/1/0000368.pd