ABSTRACT
Twenty five normal male guinea pigs were used to evaluate the effects of norfloxacin, a new antibiotic member of the quinolone group, on the Kidney by means of histological and histochemical techniques. Animals were classified into 5 groups. The first one received no treatment and considered as control group. The second and third groups received the therapeutic dose of the drug orally for one and two weeks respectively. The fourth group received triple the therapeutic dose of the drug for 2 weeks. Double the therapeutic dose was given to the fifth group for 2 weeks, then received no treatment for another 2 weeks, withdrawal group. The Kidneys of animals of the third and fourth groups showed congestion of the interlobular vessels, cloudy swelling of the convoluted tubules with hyaline and granular casts in the lumena of distal and collecting tubules. Decrease of PAS positive materials specially in the brush broders of the tubules, while increase of sudanophilia and acid phosphatase activity in proximal and distal convoluted tubules were noticed. Alkaline phosphatase and G6Pase enzymes were decreased in the convoluted tubules. Non-specific esterase enzyme increased in the proximal convoluted tubules. These changes were more pronounced in the fourth group. The animals of withdrawal group showed normalization of the histological and histochemical picture of the kidney as compared with the control. These results lead to the suggestion that, although the adverse reactions of norfloxacin are reversible, this drug has the risk of occurrence of nephritis specially with increasing the dose and prolongation of the period of treatment