Pathways of glucose utilization in kidney homogenates of tuberculous and isoniazid-treated tuberculous guinea pigs

Abstract

Male albino guinea pigs were infected by injection 0.1 ml of 7-day-old culture of Mycobacterium tuberculosis , strain H 37 Rv. The animals were divided into two groups: tuberculous and tuberculous-given-isoniazid. The latter group received isoniazid solution in lieu of drinking water from the 8th to the 30th day postinfection. The animals of both groups were sacrificed 30 days after infection. Kidney homogenates were studied for the utilization of glucose-1-C 14 and glucose-6-C 14. Some data have also been obtained on levels of succinic, isocitric and glucose-6-phosphate dehydrogenases and glucose-6-phosphatase. The utilization of both glucose-1-C 14 and glucose-6-C 14 and activities of succinic and isocitric dehydrogenases were markedly lowered in tuberculous homogenates as compared to controls. The levels of glucose-6-phosphate dehydrogenase and glucose-6-phosphatase were enhanced in infected homogenates. The ratios of C 14O 2 from glucose-1-C 14 to that from glucose-6-C 14 in tuberculous homogenates were approximately two and one-half times those of controls. This was apparently due to marked reduction in utilization of glucose-6-C 14 in comparison with that of glucose-1-C 14. Administration of isoniazid to tuberculous animals from the 8th to the 30th day postinfection revealed a normal utilization of both glucose-1-C 14 and glucose-6-C 14 by kidney homogenates. The levels of succinic and isocitric dehydrogenases were restored to control levels and those of glucose-6-phosphate dehydrogenase and glucose-6-phosphatase tended to lower to base levels. It is concluded that changes in levels of enzymes reported in this investigation are probably responsible for subnormal utilization of glucose by various pathways.