Describing enzymatic hydrolysis of phosphorylcholine and D-ephedrine-o-phosphate

Acid phosphatase in the lysosomal and microsomal fractions of human prostatic epithelium

Polyacrylamide gel electrophoresis of acid phosphatase from prostatic tissue reveals one more band than seminal plasma. It was attempted to ascertain which subcellular fraction was responsible for that intracellularly localized enzyme. Prostatic epithelium from patients with prostatic hyperplasia was homogenized, and a lysosomal and microsomal fraction were prepared by differential centrifugation. These two fractions were further centrifuged on an isopycnic Percoll gradient. The intracellularly localized form of acid phosphatase was associated with the lysosomal as well as with the microsomal fraction. In a fused rocket electrophoresis experiment these acid phosphatases cross-reacted with antiserum from seminal plasma. After neuraminidase treatment of the acid phosphatase of lysosomal and microsomal origin, only one activity band was found in polyacrylamide gels. It is concluded that only one acid phosphatase protein exists in prostatic epithelium; differences in electrophoretic mobility are caused mainly by different amounts of sialic acid residues, coupled to the same protein backbone.

Immunofluorescent localization of an androgen-dependent isoenzyme of prostatic acid phosphatase in rat ventral prostate

Isoenzymes of rat ventral prostate (RVP) acid phosphatase were isolated and partially purified by ultracentrifugation, Sephadex G-100 column chromatography, and isoelectric focusing. Antisera were raised to the isoenzymes of prostatic acid phosphatase by immunization of New Zealand white rabbits. Rabbit antisera reacting specifically to homologous but not heterologous isoenzymes of acid phosphatase were then reacted with a variety of tissues using indirect immunofluorescence. The tissues included prostate, spleen, bone marrow, liver, kidney, salivary gland complex, small intestine, and adrenal glands. An antiserum against a RVP acid phosphatase isoenzyme with a pI of 4.5 (A-PAP) localized acid phosphatase only in the supranuclear region of rat ventral prostate epithelial cells, and did not react with acid phosphatase in any of the other organs tested. A-PAP did not localize acid phosphatase in the ventral prostate from rats 14 days after castration. A-PAP did localize acid phosphatase in the ventral prostate from castrated animals that were treated with testosterone. These results indicate the A-PAP localized an androgen-dependent isoenzyme of acid phosphatase in RVP epithelial cells that may be secretory in nature. This antiserum should prove to be an ideal marker for studies involving hormonal regulation of prostatic epithelial function in vivo and in vitro.

The immunohistochemical detection of prostatic acid phosphatase: its possibilities and limitations in tumour histochemistry

The immunological specificity of the Amsterdam rabbit antiserum against human prostatic acid phosphatase was studied on paraffin sections of 200 prostatic carcinomas and 330 control tissues using an indirect peroxidase technique. Peripheral blood leucocyte smears were also investigated with a fluorescent technique. In a limited number of cases, the mixed aggregation immunocytochemical method was also applied as post-primary incubation procedure. The diaminobenzidine (DAB) final reaction product of the peroxidase technique, carried out under standard conditions, was quantified in some cases using the Leyden Television Analysis System (LEYTAS) with a built-in standard. A positive reaction was obtained in 96.5% of the prostatic carcinomas. Only 2.1% of the non-prostatic tumour cases (23 types) showed a positive reaction, namely six out of 10 insulomas and one out of 10 carcinoid tumours. The beta-cells of the normal islet of Langerhans and the leucocytes in the smears showed a positive reaction. The sensitivity of the peroxidase method, judged subjectively, is not only dependent on the circumstances of fixation, embedding and incubation but also on the degree of tumour differentiation. None of the three prostatic carcinomas studied reached the level of DAB staining intensity shown by the hyperplastic prostatic epithelium.

Comparative investigation of the mixed aggregation immunocytochemical technique and the indirect peroxidase technique for the detection of prostate specific acid phosphatase in paraffin or paraplast sections

The results obtained with the indirect peroxidase technique for the identification of prostate specific acid phosphatase in formalin fixed, paraffin or paraplast embedded autopsy material are compared with the results obtained with the mixed aggregation immuno-cytochemical technique. When using a monospecific antiserum the former technique is prefered. However, when a monospecific antiserum is not available, one has to balance the advantages of the mixed aggregation immuno-cytochemical technique against the disadvantages of having to prepare a monospecific antiserum, necessary for the indirect peroxidase technique. Both methods appeared positive in 20 prostatic carcinomas and in 36 metastases of prostatic carcinomas. In the epithelium of the seminal vesicles and in osteoclasts no acid phosphatase could be detected with the antiserum. A comparison of both techniques, as well as different types of preincubation to diminish nonspecific background staining are discussed.