Differential processing of prodynorphin and proenkephalin in specific regions of the rat brain.
Prodynorphin-derived peptides [dynorphin A (Dyn A)-(1-17), Dyn A-(1-8), Dyn B, alpha-neo-endorphin, and beta-neo-endorphin] and proenkephalin-derived peptides [[Leu]enkephalin [( Leu]Enk) and [Met]enkephalin-Arg6-Gly7-Leu8 [( Met]Enk-Arg-Gly-Leu]) in selected brain areas of the rat were measured by specific radioimmunoassays. We report here that different regions of rat brain contain strikingly different proportions of the prodynorphin and proenkephalin-derived peptides. There is a molar excess of alpha-neo-endorphin-derived peptides over Dyn B and Dyn A-derived peptides in many brain areas. [Leu]Enk concentrations exceed those of [Met]Enk-Arg-Gly-Leu in certain brain areas such as the substantia nigra, dentate gyrus, globus pallidus, and median eminence (areas rich in dynorphin-related peptides). These results indicated that (i) there is differential processing of prodynorphin in different brain regions and (ii) [Leu]Enk may be derived from Dyn A or Dyn B (or both). In certain brain regions [Leu]Enk may derive from two separate precursors (prodynorphin and proenkephalin) in two distinct neuronal systems.
D000679:Amygdala / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism*; D004745:Enkephalins / Q000378:metabolism*; D005917:Globus Pallidus / Q000378:metabolism; D008297:Male; D008473:Median Eminence / Q000378:metabolism; D011301:Preoptic Area / Q000378:metabolism; D011498:Protein Precursors / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013378:Substantia Nigra / Q000378:metabolism; D014018:Tissue Distribution
D004745:Enkephalins; D011498:Protein Precursors; C029992:proenkephalin; C033660:preproenkephalin