Uridine, xanthine, and urate contents in human seminal plasma.

Levels of uridine, xanthine, and urate in the seminal plasma of 73 men with various infertility problems as well as 11 previously fertile men after vasectomy were estimated. Very high concentration (in the mmolar range) compared with other body fluids were recorded for uridine and xanthine, while urate was in about equimolar concentration to that in the serum. Both uridine and xanthine mean values were significantly increased in vasectomized men compared with normal men; otherwise, there was a wide overlapping of the mean values of these two compounds between the two groups. The mean value of urate was maintained at a rather constant level in the two groups. Analysis of "split" fractions favors an origin from prostatic fluid for xanthine and urate and from the seminal vesicles for uridine. Uridine was positively correlated to both fructose and xanthine in oligozoospermic men, to only xanthine in normal men, and negatively to urate in vasectomized men. Urate and xanthine correlated positively in normal and oligozoospermic men. Positive correlations were also observed for xanthine and fructose in oligozoospermic men and for urate and sperm concentration in normal men.