Effect of intramuscular injection of kanamycin(KM)(400mg/kg, for 10 successive days) on glucose metabolism in the cochlea, kidney, liver and brain of the guinea pig was investigated.
The results obtained were as follows:
(1) Histological studies demonstrated morphological damages occurring in hair cells of the organ of Corti, especially outer hair cells on basal end(hook), and proximal tubules of the kidney.
(2) Biochemical studies revealed that in the organ of Corti and kidney, activities of hex-okinase and phosphofructokinase, regulatory enzymes of the activity of anaerobic glycolysis were reduced significantly, whereas those of glucose 6-phosphate dehydrogenase and 6-phosph-ogluconate dehydrogenase, regulatory enzymes of the activity of hexosemonophosphate pathway, (HMP) were not altered.
(3) Histochemical studies demonstrated that the activity of succinate dehydrogenase, regu-latory enzyme of the activity of TCA cycle, was reduced in the organ of Corti and the tubule of the kidney, respectively.
(4) The conversion of glucose into CO2 via glycolysis and TCA cycle was significantly inhibited in the cochlea and kidney and this change was not compensated by HMP.
(5) The formation of oto- and nephro-toxic effects of KM may he explainable at least in part by these changes in the glucose metabolism observed selectively in the organ of Corti and kidney.
(6) The present results suggest that the administration of drugs involved and/or related to the glucose metabolism such as pantothenic acid, thiamine, ATP or NAD may be useful for the treatment of deafness caused by the KM administration.
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