Search PubMed⌕ Search

Biomedical subjects

F H De Jong

Publications and source records attributed to F H De Jong.

At least 19 recordsLinked to original sources
PubMed2002

Enhanced serum oestrogen levels and highly steroidogenic, luteinized atretic follicles in the ovaries of the Djungarian hamster (Phodopus sungorus) kept under a short photoperiod from birth.

OBJECTIVE: In contrast to the elaborate information available on the effects of the photoperiod on the testes of hamsters, little is known about the influence on their ovaries. This study aimed to describe the ovarian follicular development and steroid hormone production in Djungarian hamsters kept from birth under a short daylight regime. DESIGN AND METHODS: Female Djungarian hamsters (Phodopus sungorus) were kept under two different light regimes: (i) 16 h light:8 h darkness (long daylight; LD) and (ii) 4 h light:20 h darkness (short daylight; SD). They were killed at 28, 56 and 80 days after birth; blood and ovaries were collected. Ovaries were either fixed in Bouin's solution or frozen. Fixed material was dehydrated, embedded in paraffin, serially sectioned at 5 microm and stained with haematoxylin and eosin, whereafter all healthy and atretic follicles were classified and counted. 3beta-Hydroxysteroid dehydrogenase (3beta-HSD) was histochemically demonstrated in 10 microm sections of frozen ovaries. Serum oestradiol-17beta and progesterone levels were determined by RIA. RESULTS: The numbers of healthy preantral and antral follicles were higher in LD than in SD hamsters. Antral follicles did not significantly differ in number during development in LD hamsters, but they were completely absent from 80-day-old SD animals. In LD animals the number of apoptotic preantral follicles dramatically increased with age. In SD animals the numbers of apoptotic antral follicles strongly decreased with age, whereas numerous non-apoptotic follicles with luteinized granulosa cells and a degenerated oocyte appeared, and in increasing numbers with age. During development, moderate 3beta-HSD activity was present in interstitial cells, theca cells of healthy follicles, and in both theca and granulosa cells of degenerating follicles. Strong enzyme activity was found in the hypertrophied granulosa cells of luteinized atretic follicles. Mean serum progesterone values varied from 2 to 6 nmol/l and were not different in LD and SD hamsters. Mean serum oestradiol levels varied from 132 to 542 and 325 to 2353 pmol/l in LD and SD hamsters respectively. The highest oestradiol levels were found in SD animals at day 28 of development. CONCLUSIONS: Folliculogenesis was dramatically disturbed in Djungarian hamsters raised under a short photoperiod. These animals developed high serum oestradiol levels and numerous luteinized atretic follicles with highly steroidogenic granulosa cells, which appear to be the source of the increased serum oestradiol levels.

3-Hydroxysteroid Dehydrogenases↗
PubMed2001

Increased serum inhibin B levels after varicocele treatment.

OBJECTIVE: Inhibin B is secreted by Sertoli cells in response to FSH and is the major feedback regulator of FSH secretion in man. The serum inhibin B level has emerged as a good marker of spermatogenesis and Sertoli cell function. Varicocele has been associated with infertility and disturbed spermatogenesis. We have studied the effect of varicocele treatment on serum inhibin B levels, with the aim of investigating the effect on spermatogenesis and the involvement of the Sertoli cell in varicocele pathophysiology. DESIGN AND PATIENTS: In a pre-post test design, the effect of varicocele surgery on inhibin B levels was studied in 30 infertile men. MEASUREMENTS: Endocrinology (inhibin B, FSH, LH, SHBG and testosterone) and semen analysis (sperm concentration, motility and morphology). RESULTS: In men receiving varicocele treatment, a significant increase in serum inhibin B levels was observed from 133.9 +/- 13.4 pretreatment to 167.8 +/- 16.1 ng/l after treatment (mean +/- SEM, P < 0.0001). No significant changes were observed in serum levels of FSH, LH and testosterone. The serum SHBG level decreased from 32.9 +/- 3.5 to 28.6 +/- 3.4 nmol/l (mean +/- SEM, P = 0.04) and the free androgen index was significantly increased from 66 +/- 5.9 pretreatment to 85 +/- 6.8 after treatment (P = 0.02, mean +/- SEM). Semen analysis showed a significant improvement in sperm concentration, from 6.5 +/- 1.9 pretreatment to 19.3 +/- 4.9 x 106/ml after treatment (P = 0.003, mean +/- SEM), and in sperm motility from the baseline level of 17 +/- 3 to 32 +/- 4% after treatment (P = 0.001, mean +/- SEM). CONCLUSIONS: Varicocele treatment can increase serum inhibin B levels, indicating improvement of spermatogenesis and Sertoli cell function. This finding suggests that the pathophysiology of varicocele involves impairment of Sertoli cell function or a different distribution of germ cell stages.

Adult↗
PubMed2000

Decrease of free thyroxine levels after controlled ovarian hyperstimulation.

Controlled ovarian hyperstimulation could lead to opposing effects on thyroid function. Therefore, in a prospective study of 65 women undergoing controlled ovarian hyperstimulation, thyroid hormones, T4-binding globulin, TPO antibodies, gonadotropins, estradiol, and PRL were measured before and after controlled ovarian hyperstimulation. After ovarian stimulation (mean +/- SE of mean): free T4 decreased, 14.4 +/- 0.2 vs. 12.9 +/- 0.2 pmol/L (P < 0.0001); thyroid-stimulating hormone increased, 2.3 +/- 0.3 vs. 3.0 +/- 0.4 mU/L (P < 0.0001); T4-binding globulin increased, 25.2 +/- 0.7 vs. 33.9 +/- 0.9 mg/L (P < 0.0001); total T4 increased, 98.1 +/- 2.3 vs. 114.6 +/- 2.5 nmol/L (P < 0.0001); total T3 increased, 2.0 +/- 0.04 vs. 2.3 +/- 0.07 nmol/L (P < 0.0001); TPO antibodies decreased, 370 +/- 233 U/mL vs. 355 +/- 224 U/mL (P < 0.0001); LH decreased, 8.1 +/- 1.1 vs. 0.4 +/-0.1 U/L (P < 0.0001); FSH did not change, 6.5 +/- 0.6 vs. 7.9 +/- 0.9 U/L (P = 0.08); human CG increased, <2 +/- 0.0 vs. 195 +/- 16 U/L (P < 0.0001); estradiol increased, 359.3 +/- 25.9 pmol/L vs. 3491.8 +/-298.3 pmol/L (P < 0.0001); and PRL increased, 0.23 +/- 0.02 vs. 0.95 +/- 0.06 U/L (P < 0.0001). Because low maternal free T4 and elevated maternal thyroid-stimulating hormone levels during early gestation have been reported to be associated with impaired psychomotor development in the offspring, our findings indicate the need for additional studies in the children of women who where exposed to high levels of estrogens around the time of conception.

Adult↗
PubMed1998

A polymorphism in the glucocorticoid receptor gene may be associated with and increased sensitivity to glucocorticoids in vivo.

We investigated whether a polymorphism at nucleotide position 1220, resulting in an asparagine-to-serine change at codon 363 in the glucocorticoid receptor (GR) gene is associated with an altered sensitivity to glucocorticoids. In a group of 216 elderly persons, 13 heterozygotes for the N363S polymorphism were identified by PCR/single strand conformation polymorphism analysis. In 2 dexamethasone (DEX) suppression tests (DSTs), using 1 and 0.25 mg DEX, the circulating cortisol and insulin concentrations were compared between N363S carriers and controls. In the 1-mg DST, there were no differences between N363S carriers and controls, with respect to adrenal suppression, but there was a significantly higher (P < 0.05) insulin response in N363S carriers. In the 0.25-mg DST, a significantly larger (P < 0.05) cortisol suppression and higher (P < 0.05) insulin response were seen in N363S carriers. Comparison of blood pressure, body mass index (BMI), and bone mineral density (BMD) between the N363S carriers and controls showed that N363S carriers had a higher (P < 0.05) BMI but normal blood pressure. There was an obvious trend towards lower age-, BMI-, and sex-adjusted BMD in the lumbar spine in N363S carriers. GR characteristics measured in 41 controls and 9 N363S carriers in peripheral mononuclear leucocytes showed no differences between N363S carriers and controls, with respect to GR number and ligand binding affinity. However, there was a trend towards greater sensitivity to DEX in the carriers' lymphocytes, in a mitogen-induced cell proliferation assay. In transfection assays, the capacity of the codon 363 variant to activate mouse mammary tumor virus promotor-mediated transcription in COS-1 cells was unaltered, when compared with the wild-type GR. We conclude that in 6.0% of our study population, a polymorphism in codon 363 of the GR gene was found. Individuals carrying this polymorphism seemed healthy at clinical examination but had a higher sensitivity to exogenously administered glucocorticoids, with respect to both cortisol suppression and insulin response. Life-long exposure to the mutated allele may be accompanied by an increased BMI and a lowered BMD in the lumbar spine but does not affect blood pressure.

Aged↗
PubMed1998

Serum inhibin B as a marker of spermatogenesis.

Inhibin B is produced by Sertoli cells, provides negative feedback on FSH secretion, and may prove to be an important marker for the functioning of seminiferous tubules. The purpose of the present study was to examine the relationship between the spermatogenic function of the testis of subfertile men and the plasma concentrations of inhibin B and FSH. These parameters were estimated in a group of 218 subfertile men. Serum inhibin B levels were closely correlated with the serum FSH levels (r = -0.78, P < 0.001), confirming the role of inhibin B as feedback signal for FSH production. The spermatogenic function of the testis was evaluated by determining testicular volume and total sperm count. Inhibin B levels were significantly correlated with the total sperm count and testicular volume (r = 0.54 and r = 0.63, respectively; P < 0.001). Testicular biopsies were obtained in 22 of these men. Inhibin B was significantly correlated with the biopsy score (r = 0.76, P < 0.001). Receiver operating characteristic analysis revealed a diagnostic accuracy of 95% for differentiating competent from impaired spermatogenesis for inhibin B, whereas for FSH, a value of 80% was found. We conclude that inhibin B is the best available endocrine marker of spermatogenesis in subfertile men.

Adult↗
PubMed1995

Endocrine activity of the postmenopausal ovary: the effects of pituitary down-regulation and oophorectomy.

The endocrine activity of the postmenopausal ovary and the effect of pituitary down-regulation were studied in a group of 35 postmenopausal women. All women underwent oophorectomy with or without hysterectomy. Fifteen women received a single dose of a depot GnRH agonist (GnRHa) 2 weeks before operation, whereas 20 women formed the control group. Peripheral venous levels of LH, FSH, estrone, 17 beta-estradiol, testosterone (T), androstenedione (A), sex hormone-binding globulin, and dehydroepiandrosterone sulfate were measured 2 weeks before, during, and 6 weeks after surgery. Ovarian venous blood was sampled during surgery. In the GnRHa and control groups, ovarian venous levels of A and T were significantly higher, and those of dehydroepiandrosterone sulfate and sex hormone-binding globulin significantly lower, compared to the peripheral levels. A significant decrease in T was found in the peripheral and ovarian vein samples during pituitary down-regulation with GnRHa. Six weeks after operation, peripheral T levels were significantly lower than those during surgery in the group that was down-regulated at the time of oophorectomy. We conclude that the postmenopausal ovary produces significant amounts of A and T, although only T contributes significantly to its peripheral serum levels. T production by the postmenopausal ovary is in part stimulated by the high levels of circulating gonadotropins, although pituitary down-regulation does not completely abolish androgenic activity.

Aged↗
PubMed1992

The effect of hypothyroidism on Sertoli cell proliferation and differentiation and hormone levels during testicular development in the rat.

In this study we show that 6-propyl-2-thiouracil (PTU) treatment of Wistar rats from birth up to day 26 p.p. retards the morphological differentiation of Sertoli cells, and prolongs the proliferation of these cells up to day 30. Sertoli cell numbers per testis, determined at day 36, were increased by 84% compared to controls. PTU treatment increased serum thyroid-stimulating hormone (TSH) levels and reduced serum levels of thyroxine (T4) from 5 days onwards, indicative of severe hypothyroidism. Follicle-stimulating hormone (FSH) levels were reduced from day 5 to 9, normal at day 12 and 16, and reduced again from day 20 to 36. Inhibin levels were decreased from day 9 to 20 and increased at 36 days of age. The increase in the number of Sertoli cells per testis in PTU treated rats, as has been reported in the present study, is likely to be responsible for the increased testis size observed by other groups (1) in these animals, when adult.

Aging↗
PubMed1991

Ovulation rate, follicle population and FSH levels in cyclic rats after administration of an inhibin-neutralizing antiserum.

Ovulation rate, follicle growth, serum FSH and oestradiol concentrations were studied after a single intraperitoneal injection of inhibin antiserum in 5-day-cyclic rats. Control rats received (non-immune) serum from castrated sheep or saline. Rats were injected at 10.00 h on dioestrus-1 (D1), i.e. the day following the day of oestrus, or at 17.00 h on dioestrus-2 (D2). The ovaries were excised at necropsy 48 h after injection, or at first or second oestrus after injection. After routine histology fresh corpora lutea were counted and/or differential follicle counts were made. Results from rats injected with either (non-immune) serum from castrated sheep or with saline were not different and were therefore combined to form the control group. The activity of inhibin-neutralizing antibodies in the circulation of antiserum-treated rats was reduced by approximately 39% between 8 h and second oestrus after injection, as determined by the binding of purified bioactive radioiodinated 31 kDa bovine inhibin. Rats were injected on D1 and killed at first oestrus. The number of fresh corpora lutea was significantly higher in antiserum-treated rats than in controls (13.9 +/- 0.4 vs 11.8 +/- 0.4; P less than 0.05). Other rats injected on D1 were killed either 48 h or at the second oestrus after injection. Blood was collected 8, 16, 24 and 48 h and at first and second oestrus after injection.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Treatment of breast cancer with different antiprogestins: preclinical and clinical studies.

UNLABELLED: Treatment with antiprogestins is a new treatment modality for breast cancer. Previously, in rats with DMBA-induced mammary tumors we observed significant growth inhibitory effects of chronic treatment with the antiprogestin mifepristone (RU486). In addition, in 11 postmenopausal breast cancer patients, we observed one objective response, six instances of short-term stable disease, and four instances of progressive disease. Side-effects appeared mainly due to antiglucocorticoid properties of the drug. Increased plasma estradiol levels were observed which probably resulted from ovarian (rat) and adrenal (patients) steroidogenesis. Combined treatment with an antiestrogen in the rat model caused additive growth inhibitory effects. Tumor inhibition after single treatment with mifepristone or tamoxifen was 90 and 75%, respectively. In contrast, when combined, tumor remission similar to that caused by LHRH-agonist treatment (50%) was observed. Even higher tumor remission was found after combined treatment with mifepristone plus LHRH-agonist (75%). In first studies in the rat model we observed significant tumor growth inhibitory effects with two new antiprogestins of seemingly greater potency which cause less unfavorable endocrine side-effects. IN CONCLUSION: combined treatment (antiprogestin plus antiestrogen or LHRH-agonist) may be of value in endocrine therapy of breast cancer.

Adult↗
PubMed1990

Inhibin immunoreactivity in gonadal and non-gonadal tumors.

Inhibin immunoreactivity was estimated in a number of gonadal and non-gonadal tumors. Dog Sertoli cell tumors and human granulosa cell and Leydig cell tumors contained high concentrations of inhibin-like material. Levels, comparable with those in normal testes and ovaries were detected in human testicular non-seminomas and in ovarian cystadenomas, thecomas and adenofibromas. No activity was found in human testicular Sertoli/Leydig cell tumors and seminomas and in ovarian adenocarcinomas, teratomas and a dysgerminoma. Furthermore, human adrenal cortical tissue (tumor and hyperplastic adrenal) contained inhibin immunoreactivity. No activity was found in human tumors of the stomach, gut, liver, kidney, pancreas and mammary gland or in meningiomas. It is concluded that inhibin is not a good marker for specific gonadal tumors. Inhibin might have intratumor actions as a growth or differentiation factor.

Animals↗
PubMed1990

Effects of low testosterone levels and of adrenal androgens on growth of prostate tumor models in nude mice.

Two transplantable, androgen dependent prostate tumor models of human origin, PC-82 and PC-EW, were used to study the effect of low androgen levels and adrenal androgens on prostate tumor cell proliferation. Tumor load of the PC-82 and PC-EW tumors could be maintained constant when plasma testosterone levels were 0.8 and 0.9 nmol/l, respectively, corresponding with an intratissue 5 alpha-dihydrotestosterone level of 3-4 pmol/g tissue. This critical androgen level for prostate tumor growth stimulation amounted to 2-3 times the castration level and proved to be similar for both tumor models. Relatively high levels of androstenedione resulted in physiological levels of plasma testosterone causing androgen concentrations in PC-82 tumor tissue exceeding the critical level for tumor growth. These results indicate that submaximal suppression of androgens can stop tumor growth in these prostate tumor models.

Animals↗
PubMed1990

Bioactive and immunoreactive FSH in serum of normal and oligospermic men.

In men suffering from idiopathic oligospermia and azoospermia the hypothesis was tested that decreased spermatozoa production could be due in part to inadequate hormonal stimulation of spermatogenesis. In 53 healthy male subjects with normal spermatozoa production (n = 10), varying degrees of oligospermia (n = 40), and azoospermia (n = 3), serum immunoreactive LH, testosterone (T), and oestradiol (E2), and immunoreactive and bioactive FSH concentrations were determined. FSH bioactivity was estimated using the rat granulosa cell aromatase bioassay. Mean LH, T, and E2 levels were similar in the control group (spermatozoa concentration greater than 40 x 10(6)/ml) compared with men exhibiting mild (10-20 x 10(6)/ml), moderate (5-10 x 10(6)/ml), or severe oligospermia (1-5 x 10(6)/ml), and in the azoospermia group. An inverse correlation was found between immunoreactive FSH levels and spermatozoa concentration (P less than 0.05), with elevated levels (twofold increase) of FSH in the combined severe oligospermia and azoospermia (P less than 0.01) groups. Moreover, augmented (P less than 0.01) bioactive FSH levels were also observed in this group of patients. The mean bioactive to immunoreactive FSH ratio was also negatively correlated with sperm counts (P less than 0.005). In addition, T/LH ratios were inversely correlated with immunoreactive (P less than 0.05) and bioactive (P less than 0.05) FSH, which may indicate that altered Leydig cell function is involved in the augmented secretion of FSH. The data presented in this study indicate that immunoreactive FSH, as measured in oligospermia and azoospermia, does not exhibit decreased bioactivity.

Estradiol↗
PubMed1990

Prolonged treatment with the GnRH analogue buserelin does not affect alpha-subunit production by the pituitary gonadotroph.

Seven patients with metastatic prostatic cancer were treated with biodegradable implants of the GnRH analogue buserelin and six were treated with buserelin intranasally. After 4-24 weeks of treatment mean serum testosterone concentrations were significantly lower in the patients treated with implants than in those treated intranasally (0.7 vs 1.7 nmol/l respectively; P less than 0.01). Also, serum LH concentrations were significantly lower in the group treated with implants. Serum alpha-subunit concentrations were significantly higher than pretreatment values during buserelin treatment. However, the sum of the concentrations of alpha-subunit present either as free alpha-subunit or as a part of LH did not differ significantly from pre-treatment values after 8 weeks or more of buserelin treatment. During buserelin treatment serum LH concentrations measured by radioimmunoassay (RIA) were higher than those measured by immunoradiometric assay (IRMA). Cross-reactivity of alpha-subunit in the LH RIA accounted for many, but not all, of the observed discrepancies. We conclude that: (1) the principal long-term effect of prolonged buserelin administration on the pituitary gonadotroph is the suppression of LH beta production, while alpha-subunit production is not affected; (2) the serum concentrations of bioactive LH are better reflected by LH concentrations measured by IRMA than by those measured by RIA. (3) Subcutaneous application of biodegradable buserelin implants is more effective in suppressing serum LH and testosterone concentrations than intranasal buserelin application.

Buserelin↗
PubMed1990

Increase in plasma prorenin during the menstrual cycle of a bilaterally nephrectomized woman.

To investigate the origin of the prorenin peak that occurs during the normal menstrual cycle, plasma levels of prorenin, renin, oestradiol, progesterone, LH and FSH were measured serially in a nephrectomized woman having regular haemodialysis. The prorenin peak coincided with the LH surge and preceded the rise of progesterone, whereas renin was below the detection limit during the whole cycle. These findings indicate that the rise in prorenin during the menstrual cycle is not of renal origin but is probably due to increased production by the ovary and supports the increasing evidence for the existence of a local renin-angiotensin system in the ovary.

Adult↗
PubMed1989

Sex hormone binding globulin in postmenopausal women: a predictor of osteoporosis superior to endogenous oestrogens.

To quantify the role of endogenous oestrogen activity in osteoporosis we measured relative metacarpal cortical area (RCA), body mass, serum oestrone, oestradiol, androstenedione, and sex hormone binding globulin (SHBG) in 746 postmenopausal women aged 53 to 76 years, sampled from the general population. The occurrence of fractures and the rate of loss of RCA (delta-RCA) were determined over the previous 9 years. Both RCA and delta-RCA were significantly related to body mass, serum oestrone, oestradiol, and SHBG. The influence of the first three variables appeared to be bone preserving, whereas the latter appeared to be bone wasting. Serum oestradiol, SHBG and body mass proved to have an independent relationship with RCA in multivariate regression analysis. The relationship to delta-RCA was statistically independent for serum SHBG only. Serum androstenedione was unrelated to either RCA or delta-RCA. In the total study population, body mass, serum oestrone, oestradiol and SHBG were not related to the occurrence of fractures over the previous 9 years. In the subgroup of 249 elderly women, aged 65-76 years, SHBG levels were significantly higher for women with type I osteoporotic fractures (vertebral and forearm fractures) as compared to controls. The results suggest a bone wasting influence of SHBG in postmenopausal women, possibly resulting in an increased risk of type I osteoporotic fractures in elderly women.

Androstenedione↗
PubMed1989

Endocrine and antitumor effects of combined treatment with an antiprogestin and antiestrogen or luteinizing hormone-releasing hormone agonist in female rats bearing mammary tumors.

Rats bearing mammary tumors induced with dimethylbenzanthracene were treated with the antiprogestin mifepristone (RU486; 10 mg/kg.day, sc), the antiestrogen tamoxifen (400 micrograms/kg.day, sc), LHRH agonists administered by either sc injections (buserelin; 40 micrograms/kg.day) or implant (buserelin or zoladex), or combinations of mifepristone and tamoxifen or LHRH agonists. Single treatment with mifepristone or tamoxifen caused a significant inhibition of tumor growth (90% and 75%, respectively), but no tumor remission. In contrast, single treatment with LHRH agonists caused remission of mammary tumor growth by 50% (injection) or 70% (implant), respectively. Combined treatment with mifepristone and tamoxifen caused additive tumor growth inhibitory effects resulting in the same extent of tumor remission as that observed after treatment with LHRH agonist injections alone. Combination of mifepristone with either manner of LHRH agonist administration resulted in the highest tumor remission (approximately 75%). Significant reductions in cytosolic steroid (estrogen and progesterone) receptor contents of mammary tumors were noted after various treatment modalities. The most pronounced decrements were observed after combined treatment with mifepristone and tamoxifen (residual estrogen receptor; 10%; residual progesterone receptor, 0%). On the other hand, suppression of pituitary-ovarian function was most pronounced after treatment with LHRH agonist implants alone or in combination with mifepristone. It is concluded that combination treatment with an antiprogestin and an antiestrogen or an LHRH agonist may be of great value in the endocrine therapy of breast cancer.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1989

The new aromatase inhibitor CGS-16949A suppresses aldosterone and cortisol production by human adrenal cells in vitro.

CGS-16949A is a new orally active nonsteroidal aromatase inhibitor which is more than 100-fold more potent than aminoglutethimide. This compound is an imidazole derivative, and therefore, its possible effect on cytochrome P-450-dependent enzyme activities in the adrenal gland was evaluated. In vitro investigations with dispersed normal and hyperplastic human adrenocortical cells showed that CGS-16949A at 10(-7)-10(-6) M is a potent 11 beta-hydroxylase inhibitor, which inhibits ACTH-stimulated cortisol release to a similar extent as an equimolar concentration of metyrapone (IC50 for both compounds, 10(-7)-5 X 10(-7) M). Etomidate was a more potent 11 beta-hydroxylase inhibitor (IC50, approximately 10(-8) M), while 10(-7)-10(-6) M ketoconazole caused (via 17 alpha-hydroxylase inhibition) a similar inhibition of cortisol release as 10(-7) M CGS-16949A (IC50, 10(-7)-5 X 10(-7) M). The 11 beta-hydroxylase inhibition by CGS-16949A was accompanied by a dose-dependent increase in the release of precursor steroids by the adrenocortical cells in vitro, including deoxycortisol, 17-hydroxyprogesterone, and androstenedione. Aldosterone release was suppressed 50% by 10(-9) M CGS-16949A, while the IC50 for cortisol in the same cells was 10(-7) M. Aldosterone release by the dispersed adenoma cells obtained from a patient with primary aldosteronism was also significantly suppressed by CGS-16949A. We concluded that 1) the new nonsteroidal aromatase inhibitor CGS 16949A is an inhibitor of 11 beta-hydroxylase which is equipotent to metyrapone. At present it is unclear whether the compound at the dose that causes complete aromatase inhibition in vivo also affects stress-induced cortisol release in man. 2) CGS-16949A exerts a very potent inhibitory effect on normal aldosterone release (IC50, 10(-9) M) and on tumorous aldosterone secretion. CGS-16949A might, therefore, be a drug that can be used in the treatment of primary hyperaldosteronism.

Adrenal Cortex↗