PubMed Health⌕ Search

Biomedical subjects

J K Grant

Publications and source records attributed to J K Grant.

At least 19 recordsLinked to original sources
PubMed1982

Saturable binding of [3H]-promegestone in sheep liver cytosol is not to receptors for progesterone or glucocorticoids.

Saturable, high affinity binding of [3H]-promegestone has been observed in sheep liver cytosol. In two tissues specimens the Kd values were 5.9 and 6.3 nmol/l, and the concentrations of binding sites were 84.5 and 66.2 pmol/g wet tissue respectively. The synthetic steroids methyltrienolone and ORG 2058 were capable of some degree of competition. Progesterone was a weak competitor; cortisol, dexamethasone and testosterone were ineffective. Bound promegestone in liver cytosol was taken up by liver nuclei, but not by sheep uterine nuclei. These promegestone-binding sites are neither progesterone or glucocorticoid receptors.

Animals↗
PubMed1982

Effect of sodium molybdate on the interaction of androgens and progestins with binding proteins in human hyperplastic prostatic tissue.

A reliable measurement of steroid hormone receptors is essential for attempts to correlate receptor levels with response to endocrine therapy in prostatic carcinoma. Evidence that receptors in many tissues are stabilized by sodium molybdate prompted the examination of the effects of this salt on the measurement of steroid-binding sites in human prostatic tissue. The presence of molybdate (10 mmol/l) during tissue homogenization, cytosol or nuclear extract preparation and binding-site assay led to a threefold increase in the amount of high-affinity androgen binding detected in cytosol, and a slight increase in the number of cytosol progestin-binding sites. The apparent binding affinity for steroids was increased in both cases. No effect of molybdate was observed on androgen-binding sites in nuclear extracts.

Cell Extracts↗
PubMed1979

Diet, absorption, and hormone studies in relation to body weight in obstructive airways disease.

Sixteen male patients with stable chronic obstructive airways disease were separated into two groups of eight according to arterial carbon dioxide tensions. Hypercapnia was associated with lower arterial oxygen tensions, higher red cell volume, and increased weight, while normocapnic subjects were decidedly thin. The considerable difference in body weight between the two groups could not be explained by variation in caloric intake, and malabsorption was excluded as a cause of weight loss in the underweight subjects. Serum tri-iodothyronine, thyroxine, cortisol, and oestradiol concentrations were similar and normal in each group, but both groups had significantly low testosterone values as compared with controls, values in the hypercapnic being appreciably lower than in the normocapnic group. The adrenal androgen dehydroepiandrosterone was significantly high in the normocapnic group and low in the hypercapnic group compared with controls. Serum pituitary luteinising and follicle stimulating hormones were normal, but three hypercapnic individuals had high serum prolactin values. Early morning urinary aldosterone values were significantly higher in the hypercapnic than in the normocapnic group. Such hormone comparisons have not previously been made in subjects with chronic obstructive airways disease grouped according to arterial blood gas values, and it is concluded that major alterations in adrenal and testicular function may occur, possibly due to pituitary suppression from hypoxia. Such hormonal changes might in part account for the contrasting alterations in body habitus found in this condition.

Aged↗
PubMed1978

Androgen binding in cytosols and nuclei of human benign hyperplastic prostatic tissue.

Androgen binding sites have been detected in cytosols and nuclear extracts from human benign hyperplastic prostatic (BPH) tissue with exchange assays using [3H]methyltrienolone and [3H]5alpha-dihydrotestosterone respectively. The concentrations of binding sites and the equilibrium dissociation constants for the [3H]steroid-receptor interactions have been determined and the specificity of the binding has been examined. The observed properties of the binding sites are consistent with those characteristic of androgen receptors. The binding sites are present in nuclear extracts from all BPH tissue samples examined to date. The amount of binding detected in the nuclear fraction is higher than that found in the cytosol.

Binding, Competitive↗
PubMed1978

Comparative studies of pulsatile and nonpulsatile flow during cardiopulmonary bypass. II. The effects on adrenal secretion of cortisol.

Previous studies have indicated that a significant reduction in plasma cortisol levels occurs during nonpulsatile cardiopulmonary bypass as a result of adrenocorticol hypofunction. The Stöckert pulsatile pump system described in Part I has been employed in a comparative study of plasma cortisol levels in 20 patients subjected to pulsatile or nonpulsatile perfusion during open-heart surgery. The plasma cortisol response pattern in the nonpulsatile group was identical to the pattern previously described, with no significant rise in cortisol levels during the period of perfusion. In the pulsatile group, however, plasma cortisol levels rose significantly during perfusion, reaching a mean level at the end of perfusion which was highly significantly greater than that in the nonpulsatile group (p less than 0.001). Correction of the plasma cortisol values for the effect of hemodilution was performed and, again, corrected cortisol values indicated a highly significant increase in end-bypass levels in the pulsatile groups (p less than 0.001). These results clearly indicate that the reduction in cortisol secretion during nonpulsatile bypass may be prevented by the use of pulsatile perfusion.

Adrenal Glands↗
PubMed1977

Biochemical investigations of separated epithelium and stroma from benign hyperplastic prostatic tissue.

Using arginase and hydroxyproline as biochemical markers, the yields and homogeneity of separated epithelial and stromal tissues from surgically removed benign hyperplastic prostate glands have been assessed. On the basis of these markers, about 30% of epithelial and 95% of stromal tissues were recovered. Dehydroepiandrosterone sulphate sulphatase activity was found predominantly in the epithelium, whereas testosterone 5alpha-reductase activity was predominantly in the stroma.

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

Binding of methyltrienolone (R1881) to a progesterone receptor-like component of human prostatic cytosol.

The synthetic steroid methyltrienolone (R1881, 17beta-hydroxy-17alpha-methyl-estra-4,9,11-trien-3-one) binds with high affinity to protein in cytosols prepared from human hyperplastic prostate. R1881 also binds to the androgen receptor of rat prostate and the progesterone receptor of rabbit uterus. Other steroids compete with R1881 for unoccupied binding sites in the human prostatic cytosols in a manner similar to that observed with the rabbit uterine progesterone receptor, rather than the rat prostatic androgen receptor. The progesterone receptor-like binding sites are a feature of the prostatic stroma rather than the epithelium.

Animals↗
PubMed1976

Prostatic distribution of sex hormone-binding globulin and cortisol-binding globulin in benign hyperplasia.

Sex hormone-binding globulin-(SHBG) and cortisol-binding globulin-(CBG) like proteins have been demonstrated in prostatic tissue surgically removed from patients with benign prostatic hyperplasia. These proteins are not easily removed by superfusion of tissue slices. Epithelial tissue was separated from stroma and found not to contain the SHBG- or CBG-like proteins. Substantial amounts of these proteins, however, remained associated with the stroma. It is suggested that they may be constituents of interstitial fluid in this tissue compartment. The possible significance of this in benign prostatic hyperplasia is discussed.

Binding Sites↗