Address for Correspondence:

Crystal aggregation and retention are critical events for the formation of kidney stones. There is a close association between crystal development and free radical activity in vivo. In the present study 30 subjects presenting with urolithiasis were included. Serum levels of total lipid peroxides, nitric oxide (as nitrite), α-tocopherol, plasma ascorbic acid (vitamin C) and erythrocyte superoxide dismutase activity were measured. These findings were compared with 30 age matched control subjects irrespective of sex. Student’s ‘t ’ test was applied for statistical analysis. There was a significant increase in lipid peroxides (p<0.001), where as significant decrease in nitrite (p<0.01) and α-tocopherol (p<0.001) levels were observed. Plasma ascorbate (p>0.05) and erythrocyte superoxide dismutase activity (p>0.05) was also found to be decreased but the difference was not statistically significant which suggests that oxidative stress is evident in urolithiasis with depletion in antioxidant status where as decrease in nitric oxide may be less abetting in disease condition