title: beta-Endorphin enhances polyamine transport in human lymphocytes.
abstract: Opioid peptides, such as beta-endorphin (beta-end), are capable of modulating in vitro proliferative response of lymphocytes. We attempted to determine the role of extracellular polyamines in the regulation of immune responses to opioid peptides by measuring the extent of polyamine uptake as adaptional response to cell activation. beta-end dose-dependently enhanced the incorporation of radioactive spermidine and spermine. When the cells were depleted of spermidine, with addition of specific inhibitors of both biosynthesis and interconversion pathway, a large increase in the incorporation of radioactive spermidine was observed. This effect appeares to be specific for beta-end, although a non-opiate-specific receptor could be involved, since beta-end-enhanced incorporation of radioactive spermidine is not blocked by naloxone. We conclude that the enhancement of polyamine incorporation may be considered as an integral component of lymphocyte activation by beta-end.
authors.affiliation: Institute of Biochemical Sciences and Clinical Biochemistry, School of Medicine, University of Messina, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Ientile
authors.forename: T
authors.initials: T
authors.lastname: Ginoprelli
authors.forename: G
authors.initials: G
authors.lastname: Cannavò
authors.forename: S
authors.initials: S
authors.lastname: Romeo
authors.forename: S
authors.initials: S
authors.lastname: Macaione
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D002478:Cells, Cultured; D004744:Enkephalin, Methionine / Q000031:analogs & derivatives / Q000494:pharmacology; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D009479:Neuropeptides / Q000494:pharmacology; D018377:Neurotransmitter Agents / Q000494:pharmacology; D011073:Polyamines / Q000378:metabolism*; D013095:Spermidine / Q000378:metabolism; D013096:Spermine / Q000378:metabolism; D018822:alpha-Endorphin / Q000494:pharmacology; D001615:beta-Endorphin / Q000494:pharmacology*
chemical_list: D009479:Neuropeptides; D018377:Neurotransmitter Agents; D011073:Polyamines; D013096:Spermine; D004744:Enkephalin, Methionine; D001615:beta-Endorphin; C013801:enkephalin-Met, Ala(2)-; D018822:alpha-Endorphin; D000324:Adrenocorticotropic Hormone; D013095:Spermidine