Effect of morphine on interleukin-1 and tumor necrosis factor alpha production from mouse peritoneal macrophages in vitro.
To study the influence of morphine on lymphokine production from mouse peritoneal macrophages (PM phi). The productions of interleukin-1 (IL-1) and tumor necrosis factor (TNF-alpha) from PM phi under various concentrations of morphine with or without naloxone were measured by testing thymocyte proliferation and L929 cell lysis in vitro. Both morphine (1 x 10(-8) - 1 x 10(-3) mol L-1) and naloxone (50 mumol L-1) inhibited IL-1 production from mouse PM phi primed by sodium thioglycolate. Naloxone did not block the inhibitory effect of morphine. TNF-alpha production from PM phi was inhibited by only high concentration (1 mmol L-1) of morphine which was not blocked by naloxone. Morphine had a direct inhibitory effect on PM phi, which was not mediated by opioid receptor of PM phi.