Differences of superoxide production in blood leukocytes stimulated with thymol between human and non-human primates.

Thymol induced superoxide production (O2-) by blood leukocytes was examined in various primates including man. Leukocytes of chimpanzee and hamadryas baboon cells showed only 35% of the maximal O2- production rate obtained in human cells, and those of the Japanese monkey and orang-utan failed to respond. In contrast, when cells were stimulated with 12-O-tetradecanoyl phorbol acetate, no significant difference in the O2- production rate was observed between human and monkey cells except for chimpanzee. These results showed that human leukocytes are the most sensitive to thymol among the primates tested. The responsiveness of non-human primate leukocytes could be classified into two types, African-type(chimpanzee and baboon) and Asian-type(orang-utan and macaque).