The comparition of relationships of ADMA, L-Arginine, NO levels and Arginase activity in kidney and liver in endotoxemia

The aim of this study was to investigate the relation between arginine-NO and arginine ?ADMA pathways in the kidney and the liver in guinea pigs 6 hours after the administration of endotoxin, to measure the amount of arginine and arginase activity which may be responsible for the central regulation of this pathway and to compare the results between kidney and liver.With this aim, 2 different groups of guinea pigs were formed with 10 subjects in each group. Endotoxemia group was administered 4mg/kg (E. Coli 0111:B4 type) and control group was administered the same amount of serum physiological intraperitoneally. 6 hours after administration, kidney and liver tsissues of both groups were removed and total protein, nitrite, nitrate amount and arginase activities were measured with spectrophotometer and L-arginine and ADMA levels with HPLC method.In the result of our study, it was established that, ADMA (p<0,05) and arginine (p<0,05) decreased and arginase activity (p<0,05) and NOx (p<0,05) increased in the liver and ADMA (p<0,05) and arginase activity (p<0,05) increased, NOx (p<0,05) decreased and arginine (p>0,05) increased,if not significantly, in the kidney, in endotoxemia.The findings of our study demonstrated that arginine-NO, arginine- ADMA pathway and arginase activity at 6 hours after the administration of 4mg/kg endotoxin is an important factor in endotoxin mediated liver and kidney tissue impairment. The changes observed in arginine-NO and arginine-ADMA pathways are opposite of each other. After endotoxemia, ADMA decreased and NO increased in the liver whereas ADMA increased and NO decreased in the kidney. We believe that this is the result of the functional differences in these tissues and factors influencing these parameters. However, definite finding is that arginine plays a central role in the relation between NO and ADMA formation in both tissues. In addition, arginine is necessary for arginase acivity as well. Arginase increased in both tissues, but this increase was higher in the kidney than in liver at 6 hıour. This may result from the different functions arginase enzyme may have for kidney and liver in endotoxemia.