Inactivation of Acid Phosphatase in Human Prostatic Homogenates in vitro : Role of Calcium

Abstract

IN the course of metabolic experiments carried out on homogenates prepared from fresh human adenomatous prostates, we have observed that incubation of such homogenates at 37° C. and pH 7 in tris buffer containing calcium chloride (0.02 M) resulted in a rapid loss of phosphatase activity averaging 44 per cent after 3 hr. in 32 experiments. When adenosine triphosphate (0.015 M) was added at the beginning of the incubation period, the loss of activity was reduced to an average value of 5 per cent under the same experimental conditions. Addition of adenosine triphosphate during or at the end of the incubation period resulted in complete regeneration of the acid phosphatase activity on further incubation (Fig. 1). We have observed also that adenosine triphosphate could be replaced by sodium diphosphate or ethylenediamine tetraacetic acid (versene) with identical results.