title: Characterization of immunoreactive proopiomelanocortin-related peptides in rat testes.
abstract: alpha-Endorphin, beta-endorphin, gamma-endorphin, and N-terminal ACTH immunoreactivity were detectable in acid extracts of rat testes with concentrations of 0.07 +/- 0.01, 0.18 +/- 0.03, 0.06 +/- 0.01, and 0.33 +/- 0.08 (+/- SD) pmol/g wet wt, respectively. The forms of these immunoreactive peptides were characterized by reverse phase high performance liquid chromatography. Immunoreactive beta-endorphin was also analyzed by gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The results indicated that the major form of immunoreactive beta-endorphin present appears to be beta-endorphin-(1-31). No alpha-N-acetylated forms of beta-endorphin or beta-lipotropin-sized material were detected. Immunoreactive alpha- and gamma-endorphin appear to be present as alpha-endorphin and des-Tyr1-gamma-endorphin, respectively. Immunoreactive alpha MSH was present as its desacetylated form. No immunoreactive ACTH fractionating with ACTH-(1-39) or its glycosylated forms was detected. This peptide profile is most similar to that seen for proopiomelanocortin-derived peptides in the brain. The low concentrations of these peptides in rat testes suggest a paracrine function.
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000032:analysis*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004723:Endorphins / Q000032:analysis*; D008297:Male; D010908:Pituitary Hormones, Anterior / Q000032:analysis*; D011333:Pro-Opiomelanocortin; D011498:Protein Precursors / Q000032:analysis*; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D013737:Testis / Q000032:analysis*; D018822:alpha-Endorphin; D001615:beta-Endorphin; D018823:gamma-Endorphin
chemical_list: D004723:Endorphins; D010908:Pituitary Hormones, Anterior; D011498:Protein Precursors; D001615:beta-Endorphin; D018822:alpha-Endorphin; D018823:gamma-Endorphin; D011333:Pro-Opiomelanocortin; D000324:Adrenocorticotropic Hormone