The Vehicle for Zinc in the Prostatic Secretion of Dogs

Abstract

The vehicle to which the zinc of the prostatic secretion is probably linked was analysed in two dogs, using a differentiated separation technique.

Radioactive zinc (Zn⁶⁵ Cl₂ was injected intravenously. After 24 hours the prostatic secretion was collected and its proteins were precipitated. The radioactive zinc in the secretion was not precipitated. In the supernatant it was non-dialysable (pore size 24 Å). On separation through a sephadex column the radioactive zinc did not accompany the proteins, but a fraction of lower molecular size. After hydrolysis and amino-acid analysis, this was found to be a polypeptide consisting of 8 known amino-acids. This polypeptide is probably of enzymatic significance.