Augmentation of 12-lipoxygenase activity of lymph node and spleen T cells in autoimmune mice MRL/1

To investigate the relationship between development of autoimmune disease and arachidonic acid metabolism, we compared lipoxygenase and cyclooxygenase activities of lymphoid cells in MRL/1 mice during the development of the disease. Lipoxygenase activity per cell of lymph mo mice, although cyclooxygenase activity was low in both cases. These phenomena did not depend on aging since age-matched MRL/n mice lacking the lpr gene (congenic with MRL/1 mice), and BALB/c mice did not exhibit any change in the enzyme activity with aging. The lipoxygenase activity of 4 mo MRL/1 lymph node cells came mainly from nylon wool nonadherent cells. Lipoxygenase activity of nylon wool nonadherent spleen cells in MRL/1 mice was also higher in 4 mo mice than that in 1.5 mo mice, whereas we could not detect any difference in nylon wool adherent cells. The major lipoxygenase product was 12-hydroxyeicosatetraenoic acid (12-HETE), which was identified by a high performance liquid chromatography (HPLC). Our data suggest that change in arachidonic acid metabolism in T cells may be related to development of autoimmune disease in MRL/1.