Tohru Masukawa (1), Kunio Nakanishi (1) and Reiko Natsuki (2)
(1) Department of Clinical Biochemistry, (2) Department of Toxicology,
Faculty of Pharmaceutical Sciences, Setsunan University, Nagaotogecho 45-1,
Hirakata, Osaka 573-0101, Japan
Abstract: Effects of nitric oxide (NO) synthase inhibitors on
the enoxacin-induced convulsions were examined in mice pretreated with fenbufen.
7-Nitroindazole markedly suppressed the incidence of convulsions, whereas
L-arginine did not modify the convulsions at all. The suppression of the
convulsions by 7-nitroindazole was not reversed by the pretreatment of L-arginine.
Brain NO synthase activity was significantly raised at 30 min after enoxacin
when combined with fenbufen. The increased NO synthase activity was found
to be suppressed by the pretreatment of 7-nitroindazole. These findings
suggest that endogenous NO may be involved as a proconvulsant substance
in the development of enoxacin-induced convulsions in mice pretreated with
fenbufen.
Keywords: Convulsion, Enoxacin, Nitric oxide synthase