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Biomedical subjects

J Shimazaki

Publications and source records attributed to J Shimazaki.

At least 469 records · Page 26Linked to original sources
PubMed1979

Properties of androphilic proteins in cytosols of human benign prostatic hypertrophy.

Androphilic proteins in the cytosol from the human benign prostatic hypertrophy are separated into two fractions by Sephadex chromatography; void volume fraction and IgG fraction which was eluted near the site of hIgG. In the present study, properties of these two androphilic proteins were compared. Association constants of these proteins were in the order of 10(9) M-1. However, the binding capacity of the former was smaller than that of the latter. These two androphilic proteins well bound to nuclei, and the high-affinity and saturable binding to nuclei was observed in the 3H-dihydrotestosterone-IgG fraction complex, while binding of 3H-dihydrotestosterone-void volume fraction complex to nuclei was low affinity and unsaturable. The binding of the complexes to chromatin seems to be of low affinity and nonsaturable. These androphilic proteins did not bind to calf thymus DNA. Salt extractability of the bound void volume fraction after incubation with nuclei was not different from that of the bound IgG fraction. It was observed that the chromatographic behavior of the androphilic protein in IgG fraction was changed after incubation with nuclei.

Cytosol↗
PubMed1978

Inhibition by various steroids on dihydrotestosterone binding to androphilic protein in human benign prostatic hypertrophy.

The effect of various steroidal compounds on the binding of the androphilic protein to dihydrotestosterone in the cytosol of tissues of human benign prostatic hypertrophy was examined. Androgens, as well as estrogens and gestagens showed an inhibitory effect on the binding. Non-steroidal anti-androgens were revealed to be weak inhibitors on the binding. Two androphilic proteins were observed in Sephadex G-200 chromatography in fractions eluted at the void volume and in fractions appearing at the site of IgG, and the rate of inhibition on the binding of both fractions by various steroids was compared. The rate of inhibition by various compounds was generally higher in the IgG fraction than in the void volume fraction. When the ligand and inhibitors were incubated with the cytosol prior to fractionation by Sephadex chromatography, rate of inhibition was lower than that obtained when the ligand and inhibitors were reacted with fractions after chromatography. Implications of the difference observed in these two experiments are not clear at this moment. The results obtained by the protamine precipitation experiment were almost the same as those by the experiment using the extract of the unfractionated acetone-dried cytosol, therefore, the protamine procedure does not seem to precipitate the tissue specific androphilic protein specifically.

Androgens↗
PubMed1977

Effect of hypolipidemia on testosterone-stimulated prostatic growth in castrated rats.

Hypolipidemia caused by Simfibrate feeding for 3 weeks reduced responses of weight and nucleic acid contents to testosterone administration in the ventral and dorsolateral prostates of castrated rats. However, the effect of testosterone on the contents of citrate, fructose, zinc and the activity of testosterone 5alpha-reductase in the glands of castrated animals was not modified by Simfibrate feeding.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1977

Androphilic proteins in cytosols of human benign prostatic hypertrophy.

To examine the properties of androphilic proteins in human benign prostatic hypertrophy, the binding capacity and affinity of the proteins were determined after acetone-treatment, ammonium sulfate precipitation and chromatographies of DEAE and Sephadex G-200. Androphilic proteins in the extract of acetone-dried cytosol from the hypertrophic human prostate was precipitated at 30-50% saturation of ammonium sulfate. The binding of this fraction to dihydrotestosterone and testosterone was high affinity, but the binidng to estradiol-17 beta was the one of non-specific. Androphilic proteins in the 30-50% fraction were eluted from DEAE-cellulose column by buffer containing 0.05 M KCL. On Sephadex G-200 chromatography of 30-50% fraction, the androphilic proteins were observed in three peaks; one was eluted in the void volume and other two were eluted at the sites of IgG and albumin. The amount and ratio of proteins eluted in the void volume and the site of IgG from Sephadex G-200 column were variable in individual tissue samples. The chromatographic behavior of the 30-50% fraction in Sephadex G-200 was not changed significantly by introducing 0.4 M KCl in the system. Polyacrylamide gel electrophoresis was applied for further separation of the proteins.

Ammonium Sulfate↗
PubMed1977

Dihydrotestosterone-binding protein in cytosols of normal and hypertrophic human prostates, and influence of estrogens and anti-androgens on the binding.

Dihydrotestosterone-binding protein was observed in cytosols of the normal and hypertrophic human prostates. Association constant for dihydrotestosterone of cytosol of the normal prostate differed slightly from that of the hypertrophic prostate. However, maximum binding capacity was almost identical in these tissues. No distinct correlation was detected between proportion of glandular constituent and binding characteristics (Ka and maximum binding capacity) in the hypertrophic prostates. Influence of some steroids on the binding with dihydrotesterone was examined. Testosterone, estradiol-17beta, estriol, cyproterone acetate and SK & F 7690 inhibited the binding competitively. However, Sch 13521 did not exhibit any influence on the binding.

Binding, Competitive↗
PubMed1977

Effect of estracyt on the rat prostate.

Two types of experiments were performed to elucidate the estrogenic effect of estracyt on the ventral and immature rats that had received injections of testosterone; then changes in weight of accessory rats and changes in weight of the total body, the ventral and the dorsolateral prostates, and adrenal gland, and changes in activities of testosterone 5alpha-reductase, alkaline phosphatase, and arginase of both lobes of the prostates were examined. In the second experiment, estracyt was injected into castrates rats and immature rats that had received injections of testosterone; then changes in weight of accessory sex organs were determined. Because similar changes were induced by treatment of animals with estradiol-17beta, it was concluded that the effect of estracyt on the prostates was most likely attributable to the estrogenic effect of the drug.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗