COMPARISON OF NITRIC-OXIDE PRODUCTION BY MONOCYTE MACROPHAGES IN HEALTHY-SUBJECTS AND PATIENTS WITH ACTIVE PULMONARY TUBERCULOSIS/

The aim of the present study was to determine the NO production by hum an cultured macrophages (m phi) and to compare the NO production betwe en healthy subjects and patients with active pulmonary tuberculosis. T he bioassay method was used for assessment of validation. Lipopolysacc haride (125 ng ml(-1))-activated m phi from healthy and diseased subje cts released a substantial amount of NO. NO synthase inhibitor, N-G-ni tro-L-arginine methyl ester, (0.1 mmol l(-1)) suppressed NO synthesis significantly in m phi of healthy subjects. Nitrite formation measured by the diazotization method in the supernatants taken from cultured m phi of tuberculous patients were significantly lower than the healthy subjects. The supernatants obtained in both subjects caused relaxatio ns of guinea-pig aorta reversed by methylene blue (10 mu mol l(-1)). T here was a significant difference between relaxations of healthy and d iseased supernatants. Nitrite formation measured by the bioassay metho d in the supernatants taken from cultured m phi of tuberculous patient s was significantly higher than the healthy subjects. It was concluded that NO production appeared to be decreased in tuberculosis. The reas on for decreased production of NO in tuberculosis may be related to th e interaction of several cytokines and/or eicosanoids by means of the disease related induction of immune reactions. (C) 1998 The Italian Ph armacological Society.