Cytochrome P-450 cholesterol side-chain cleavage expression in human spermatozoa.
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Adult↗
Biomedical subjects
A Loganath
Publications and source records attributed to A Loganath.
A comparative study of progesterone synthesis by term human fetal amnion and chorion.
Activity of 3 beta-hydroxysteroid dehydrogenase-5, 4-en isomerase was investigated with [7n-3H] pregnenolone as substrate in the homogenates of amnion and chorion collected from women (n = 6, age 20-34 years) after spontaneous labour at term (37-40 weeks gestation) from uncomplicated pregnancies. Controls were heat-denatured homogenates instead of fresh homogenates. Reverse-isotope dilution analysis gave positive identification of [3H] progesterone in all incubations of viable tissues. This metabolite was not evident in the controls. The extent of enzymic conversion of chorion, 1.4-31.1% was consistently higher than that of the amnion, 0.66-1.7%. The results show that the human fetal membranes can be a source of progesterone during pregnancy. The metabolic capability may have physiological significance in the induction and progression of labour to parturition.
Amnion↗
A relationship between sperm count and intracellular progesterone, 17 alpha-hydroxyprogesterone, and cortisol concentrations in human spermatozoa.
In an attempt to determine whether human spermatozoa contain steroid hormones, in this study we have measured the immunoreactive levels of P, 17 alpha-OHP, and F in the extracts of sonicated specimens of sperms obtained as ejaculates from husbands of infertile couples. The results of this study demonstrate for the first time that human spermatozoa contain definite amounts of the measured steroids and suggests an association between steroid levels and sperm count. These steroids identified intracellularly in the haploid germ cells may play a role in the molecular events associated with fertilization.
17-alpha-Hydroxyprogesterone↗
Response of ovary in young women experiencing laparoscopy under general anaesthesia.
This study investigated whether changes in circulating levels of immunoreactive oestradiol-17 beta (E2), progesterone (P) and testosterone (T) occur in women at follicular (n = 18, age 25 to 39 years) and luteal (n = 17, 25 to 39 years) phases of the normal menstrual cycles, experiencing laparoscopy after intravenous sedation with general anaesthesia. The pre- and intra-operative follicular phase plasma steroid hormone concentrations were 153.5 +/- 84.3 vs 297.4 +/- 220.8 pg/ml for E2, 2.0 +/- 3.2 vs 3.3 +/- 3.8 ng/ml for P and 746.6 +/- 415.9 vs 1325.8 +/- 535.1 pg/ml for T, respectively. The corresponding luteal phase steroid levels were 259.7 +/- 120.2 vs 382.7 +/- 188.7 pg/ml, 7.0 +/- 4.8 vs 9.9 +/- 6.1 ng/ml and 819.4 +/- 355.7 vs 1703.5 +/- 1058.1 pg/ml. Using the Wilcoxon rank sum test, intra-operative hormone levels with the exception of P in the luteal phase were found to be significantly elevated (p < 0.05). The results suggest that laparoscopy under general anaesthesia evokes increased secretion of ovarian hormones, possibly via the activation of hypothalamo-pituitary-ovarian axis.
Adult↗
In vitro formation of testosterone via the delta 5-pathway in the human umbilical cord.
Homogenates of two groups of term umbilical cord (n = 6, 37-40 weeks; n = 6, 38-40 weeks) were separately incubated with [7n-3H]pregnenolone and [1,2,6,7-3H]dehydroepiandrosterone. Using the reverse-isotope dilution technique, [3H]dehydroepiandrosterone and [3H]testosterone formed from the respective substrates were isolated and characterized. The extent of enzymic conversions were 0.015-0.28% and 0.044-2.2%. These results provide evidence for the metabolic transformation of pregnenolone to testosterone via the delta 5-3 beta-hydroxy route.
Chromatography↗
The fetal membranes as a possible source of testosterone.
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Adult↗
Human umbilical cord as a possible source of progesterone.
Homogenates of human term umbilical cord were incubated with 7n-3H-pregnenolone. Using a reverse-isotope dilution technique, 3H-progesterone was isolated and characterized. The extent of enzymic conversion ranged from 2.5 to 55.4%. The results indicate that the cord can be a source of progesterone during human pregnancy.
Adult↗
Elevated peritoneal fluid luteinizing hormone and prolactin concentrations in infertile women with endometriosis.
In this study, we compared (Mann-Whitney U-test) the peritoneal fluid FSH, LH and PRL levels, measured by RIA, at the follicular and luteal phases of the menstrual cycle in women with (n = 43; age 25-44 years) and with no evidence of endometriosis (n = 35; age 25-39 years) who were considered as controls. Both follicular and luteal phase FSH concentrations of women with endometriosis were not statistically different (n = 22 vs 18; 0.32-5.8 vs 0.50-8.2 IU/l, P = 0.247; n = 13 vs 14; 0.6-6.5 vs 0.66-6.7 IU/l, P = 0.604) compared to their respective controls. In contrast to FSH, the concentrations of LH at follicular (n = 19 vs 17; 3.1-34.2 vs 2.3-12.2 IU/l, P = 0.01) and luteal (n = 17 vs 15; 2.1-95.4 vs 1.3-17.9 IU/l, P = 0.02) phases of the test group was significantly elevated at both phases of the cycle. With respect to differences in PRL concentrations at follicular phase no significant change (n = 21 vs 16; 1030-5800 vs 1305-4650 mIU/l; P = 0.255) was observed. The greatest difference in luteal PRL concentrations (P = 0.007) was obtained between the women with endometriosis and controls (n = 17 vs 17; 1895-8600 vs 1041-5000 mIU/l). The results suggest that disordered synchronization of neuroendocrine mechanisms controlling LH and PRL may be the underlying abnormality causing infertility in our group of patients with endometriosis.
Adult↗
Cholesterol side-chain cleavage activity in the human umbilical cord in vitro.
With a view to establish whether cells of the human umbilical cord possess cholesterol side-chain cleavage activity, homogenates of term umbilical cord obtained following spontaneous vaginal delivery from uncomplicated pregnancies (n = 6; 38-40 weeks gestation) were incubated with 26-14C cholesterol. Controls were homogenates heating in a boiling water bath for 10 min. Proof of the existence of cholesterol C-20, 22-desmolase activity in the viable tissue was established by associating radioactivity due to the labelled carbon 26 of 26-14C cholesterol with the p-bromophenacyl ester of isocaproic acid by reverse-isotope dilution analysis. The desmolase efficiency expressed as specific activity of 14C isocaproic acid, dpm g-1 tissue varied from 110 to 351 with a mean of 202. The small but definite conversion indicates that the cholesterol side-chain cleavage reaction previously believed to be exclusive to the steroidogenic pathway operating in the adrenal, gonads and placenta does exist in the human term umbilical cord in vitro.
Adult↗
Upper genital tract fluid oestradiol-17 beta, progesterone and testosterone concentrations during the menstrual cycle.
This study was to obtain evidence whether a cyclical pattern in the concentrations of oestradiol-17 beta, progesterone and testosterone exists in the upper genital tract fluid of women with normal menstrual cycles. The steroid concentrations at proliferative and luteal phases were n = 20 vs 17, 54.5-190.0 vs 44.2-827.1 pg/ml; 0.27-3.3 vs 3.4-46.5 ng/ml and 41.9-734.8 vs 85.7-991.2 pg/ml, respectively. The results were analysed according to Mann-Whitney U test. Significantly higher concentrations of oestradiol-17 beta (p = 0.0036) and progesterone (p = 0.0001) were found. The results suggest the existence of a cyclical variation and point to the ovary as the main source of output of the steroids.
Adult↗
Evidence suggesting the trophoblastic origin of follicle-stimulating hormone, luteinizing hormone and prolactin in hydatidiform mole.
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Adult↗
Comparison of AFP and beta-hCG levels in infiltrating duct mammary carcinoma at different stages of malignancy.
In order to assess the likely clinical value of AFP and beta-hCG levels as markers of the extent of spread of infiltrating duct mammary carcinoma, we compared (Mann-Whitney U test) the immunoreactive tumour tissue concentrations of the respective antigens, measured by specific RIA, after mastectomy in Chinese women at stages I (n = 9), II (n = 13) and III (n = 7) with that of normal breast tissue (n = 11). Elevated concentrations of the oncofetal antigens were found at all stages of malignancy. The discovery of an hCG-like material in the extract of normal breast tissues indicates limited value of beta-hCG assay in mammary tumours. However, our findings generally suggest that measurement of the tumour tissue AFP levels warrant consideration as a useful biochemical marker for in-vitro evaluation of tumour spread at all stages of malignancy.
Adult↗
Biosynthesis of dehydroepiandrosterone by term human fetal chorion in vitro.
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Adult↗
alpha-Fetoprotein levels in fullterm and very low birthweight infants.
Plasma alpha-fetoprotein (alpha-FP) levels were determined in fullterm and very low birthweight (VLBW) infants in the first week of life and serially in a cohort of VLBW infants for the first 24 weeks after delivery. A rapid decline in alpha-FP levels was observed in both the fullterm and VLBW infants initially. Beyond 2 weeks of age, there was a gradual, linear decline until 6 weeks, followed by a more rapid period of decline from 6 to 16 weeks. The decline in the ensuing weeks demonstrated an asymptotic pattern. The half-life of alpha-FP was 7.5 days in the first week of life in both fullterm and preterm infants, 28.7 days from 2 to 6 weeks of life and 11.9 days from 6 to 16 weeks of life in VLBW infants.
Female↗
A comparative study of peritoneal fluid concentrations of oestradiol-17 beta, progesterone, and testosterone in controls and in patients with endometriosis.
To ascertain whether a cyclical variation exists in the steroid hormone concentration of the peritoneal fluid between controls and patients with endometriosis, we set out to measure the concentration of oestradiol--17 beta (E2), progesterone (P4), and testosterone (T) by specific radioimmunoassay in the peritoneal fluid of these 2 groups. Forty six patients (mean age, 30.1 +/- 6 years) with pelvic endometriosis and 32 control patients (mean age, 32.2 + 3.8 years) without endometriosis were studied. The significance of differences between groups was determined by the Mann-Whitney mu test. In the control group a significant rise in peritoneal fluid E2 (P = 0.017) and P4 (P = 0.048) levels was observed in the luteal phase compared to the follicular phase, but no such difference was noted in women with endometriosis. It is suggested that peritoneal fluid steroid hormone assays are not helpful in the evaluation of ovarian function in endometriosis.
Adult↗
Histopathology of the testes from male transsexuals on oestrogen therapy.
This study was conducted to determine whether the histopathology of the testis of the male transsexual would throw light on the pathogenesis of male transsexualism. Histological sections of testicular tissues obtained at sex reassignment surgery from phenotypic male transsexuals (n = 10, age 21-33 years) with XY sex chromosome constitution were studied by light microscopy. The patients were diagnosed on clinical and psychiatric evidence and had been on oestrogen therapy for 6-13 years. The significant histological findings in the ten subjects were: (i) Focal or normal spermatogenic activity associated with normal Leydig cell population in three cases, and (ii) Total absence of spermatogenic activity associated with reduced Leydig cell population in seven cases. We suggest that the observed histological features are due to refractoriness to oestrogen, and the iatrogenic effects of oestrogen superimposed on normal or altered hypoathalamo-pituitary function.
Adult↗
Elevated intravesicular fluid thyroid-stimulating hormone concentration in hydatidiform mole.
In an attempt to explain hyperthyroidism in hydatidiform mole, concentrations of immunoreactive thyroid-stimulating hormone (TSH) together with human-chorionic gonadotrophin (beta-hCG) were measured in the serous fluid obtained from 43 patients aged 15-45 years and with amenorrhea 11-31 weeks. Elevated concentrations of these two hormones were found in all samples. It is probable that hyperthyroidism could stem from TSH immunologically similar to pituitary TSH and distinct from hCG and luteinizing hormone (LH) that we have identified in hydatid vesicles.
Adolescent↗
Steroidogenic expression of delta 5-3 beta-hydroxy pathway of androgen biosynthesis by human breast carcinoma.
In order to determine whether human mammary tumours could contribute to cholesterol and dehydroepiandrosterone biosynthesis in breast cancer patients, incubations of homogenates of infiltrating ductal carcinoma were carried out separately with 2-14C acetate (patient, n = 6; 21-80 years) and 7n-3H pregnenolone (patient, n = 5, 36-74 years) as substrates. With the aid of the reverse-isotope dilution technique, 14C cholesterol and 3H dehydroepiandrosterone were characterized; these two gave maximum yields of 2.38 X 10(-4)% and 9.42 X 10(-2)% respectively. These results indicate that there exists a potential for the synthesis of cholesterol and dehydroepiandrosterone in vivo. It is suggested that the biosynthetic pathway involved in the synthesis of the latter is; acetyl CoA----cholesterol----pregnenolone----17 alpha-hydroxypregnenolone----dehydroepiandrosterone.
17-alpha-Hydroxypregnenolone↗