[Role of active oxygen on the progression of murine lupus nephritis]

In order to study the role of active oxygen radicals on the progression of the immune-complex (IC) nephritis, we administered superoxide dismutase (SOD), catalase (CAT), and dimethylthiourea (DMTU) to (NZB x NZW) F1 mice from 8 weeks of age, 3 times a week. At 40 weeks of age, the urine protein of the control (n = 23) was 11.4 +/- 4.1 mg/day. SOD (n = 12), CAT (n = 6) and SOD + CAT (n = 5) groups were 1.5 +/- 0.4, 25.4 +/- 14.7, 0.7 +/- 0.1 mg/day, respectively. DMTU group (n = 12) showed significantly less proteinuria (0.6 +/- 0.1 mg/day, p less than 0.05) than control. Even if the injection was begun from the late stage of the disease, some effect was observed. Moreover, by DMTU, urinary excretion ratio of PGF1 alpha/TXB2 0.025 +/- 0.003 was higher than control 0.015 +/- 0.001 (p less than 0.05). These findings suggest that oxygen radicals may play an important role during the progression of lupus nephritis. Among the oxygen radical species, hydroxyl radical is considered to be the most pathogenetic factor in IC-mediated nephritis.