The Occurrence of Intravenously Injected Radioactive Zinc in the Prostate and Prostatic Fluid of Dogs

Abstract
Prostatic fistulas were created in healthy mongrels. For prostatic stimulation pilocarpine sulfate (5 mg) was administered intravenously. Zn65 was given intravenously. Zn65 appeared in dog prostatic fluid in a highly predictable manner on repeated stimulation with pilocarpine sulfate. Radioactivity was nearly always greater in the first portion of dog prostatic fluid collected than in the second. Biopsy of various canine organs seven days after the injection of radioactive zinc revealed the radioactivity in the prostate to be much greater than that found in other tissues sampled. In the few experiments performed, estradiol produced a rapid drop in volume and both concentration and total amount of radioactivity in dog prostatic fluid. During the study periods, prostatic fluid was never obtained isotope-free, whether under the influence of estradiol or not. From the above evidence, it would appear that the presence of zinc in the prostatic fluid of dogs is associated with an integral function of the canine prostate.