Prostate gland fructose was measured enzymatically in normal and castrate mice. Regardless of protein precipitation procedure, castration resulted in a loss of prostatic fructose.
Prostate gland fructose levels were higher, using the resorcinol method, only when tricholoroacetic acid (TCA) was used to precipitate tissue proteins. Similar procedures employing supernatants obtained from barium hydroxide-zinc sulphate precipitated organs were comparable to enzymatically measured fructose.
The use of radio-active fructose and fructose-1,6-diphosphate established that heavy metal precipitation resulted in over 90% of the labelled fructose residing in the supernatant and a similar amount of phosphate ester found in the precipitate. The use of TCA to precipitate prostate gland proteins revealed that both fructose and fructose-1,6-diphosphate were predominantly found in the supernatant (93 and 95% respectively). Very little radio-activity was found in the precipitate fraction, indicating that TCA was unable to separate free hexose adequately from phosphate esters.