title: Effects of morphine and naloxone on proliferation of lymphocytes in vitro.
abstract: OBJECTIVE
  To study the effects of morphine on different lymphocytes and the influence of naloxone.
  
  
  METHODS
  The proliferation rates of unmature, resting, and activated T-lymphocytes and B-lymphocytes were determined under various concentrations of morphine with or without naloxone in vitro.
  
  
  RESULTS
  Morphine 1 x 10(-10)-1 x 10(-6) mol L-1 enhanced concanavalin A (Con A)-induced splenic T-cell proliferation, and 1 mumol L-1 enhanced lipopolysaccharide (LPS)-induced splenic B-cell proliferation. Naloxone, which per se enhanced the T-cell proliferation, blocked the enhancing effects of morphine. Morphine (1 x 10(-10)-1 x 10(-5) mol L-1) had no influence on the proliferation of resting splenocytes and Con A-induced thymus cells. Morphine 1 mmol L-1 inhibited the proliferation of resting, LPS-induced splenocytes, and Con A-induced splenic and thymus cells. These inhibiting effects were not blocked by naloxone (50 mumol L-1).
  
  
  CONCLUSIONS
  Stimulating effect of morphine on activated T- and B-cells were mediated by opioid receptors and different opioid receptors existed during the differentiation and activation of lymphocytes. The inhibitory effects of morphine (1 mmol L-1) were not mediated by opioid receptors.
authors.affiliation: Shanghai Institute of Materia Medica, Chinese Academy of Sciences.
authors.forename: T H
authors.initials: TH
authors.lastname: Bian
authors.forename: X F
authors.initials: XF
authors.lastname: Wang
authors.forename: X Y
authors.initials: XY
authors.lastname: Li
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D005260:Female; D008213:Lymphocyte Activation / Q000187:drug effects*; D051379:Mice; D008813:Mice, Inbred ICR; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology*
chemical_list: D009270:Naloxone; D009020:Morphine