Bovine spermatozoa incorporate 32Pi into ADP by an unknown pathway

Abundance of guanine, guanosine, inosine and adenosine in human seminal plasma

Guanine, guanosine, inosine and adenosine were found in large amounts in seminal plasma from 145 men, regardless of whether spermatozoa were present or not. The mean guanine level in 61 normozoospermic men was 89.7 +/- 93.1 mumol/l; this was significantly lower in 32 vasectomized men (18.9 +/- 31 mumol/l) suggesting the involvement of the epididymis in its secretion. Guanine and nucleoside levels were significantly higher in the seminal plasma of oligozoo- and azoospermic than normozoospermic men. Guanine and nucleoside levels were consistently inter-related in the seminal plasma of normozoospermic men with the best correlation between guanine and guanosine.