Comparative effects of morphine on leukocytic antigenic markers of monkeys and humans

Knowing the in vitro effects of morphine on monkey leukocytes would be helpful in extending the utility of a monkey model for psychoneuroimmunological investigations. Morphine effects on T11, Leu2a, and Leu3a antigenic markers on leukocytes from rhesus monkeys and humans were assessed by using single- and two-color cytofluorometric analyses. Kinetics of expression of these markers was determined after modulation of the original complement of T11 markers from the surface of T11(+) cells. Percentages of leukocytes detectable by directly staining these markers before modulation were within the expected range for monkey and human cells. Also, as expected, T11 modulation reduced the percentages of cells expressing T11. This reduction was particularly obvious for T11 in the single-color analyses, with reductions being greater for monkey than human cells. Furthermore, in the single-color analyses, the effects of morphine on kinetics of T11 expression were quite similar for both human and monkey cells. In the two-color analyses, the simultaneous expression of T11 and Leu3a markers was uniform for both monkey and human cells. The effects of morphine on kinetics of expression of these markers varied only slightly between species. On the other hand, the distribution of Leu2a on T11 cells was markedly different for monkey and human T-cells. Whereas all human Leu2a(+) cells expressed similar numbers of T11 receptors, monkey cells with high-density Leu2a expressed fewer T11 markers than those with low-density Leu2a. The effects of morphine on kinetics of Leu2a and T11 expression were at obvious variance between species.(ABSTRACT TRUNCATED AT 250 WORDS)