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1.
The adrenal glands lie on top of the kidneys. The adrenal medulla produces catecholamines and the adrenal cortex produces three types of steroid hormone (mineralocorticoids (aldosterone), glucocorticoids (cortisol) and androgens (dehydroepiandrosterone, DHEA)). All are synthesized from cholesterol. Cortisol secretion is controlled by adrenocorticotrophic hormone from the pituitary. It rises in response to stress and is essential for life. It stimulates gluconeogenesis, breaking down lean tissue, and is anti-inflammatory. Aldosterone secretion is controlled by angiotensin II and extracellular potassium concentrations, so is influenced by renal perfusion. It provides the fine tuning for sodium and potassium, and thus water, balance via its action on the distal renal tubule. DHEA is a weak androgen. In the male it is unimportant; in the female DHEA produced by the adrenal gland accounts for most of the androgen in the blood.  相似文献   

2.
The nonsteroidal androgen-receptor antagonist nilutamide has previously been shown to inhibit adrenal androgen steroidogenesis in patients with prostatic carcinoma treated in combination with an LHRH agonist. In order to understand better the mechanisms subserving this observation, we have studied the effects of nilutamide alone on the serum concentrations of androstenedione (A), dehydroepiandrosterone (DHEA), and DHEA-sulphate (DHEA-S) in 12 patients with prostatic cancer and compared them with those achieved in 21 patients treated with the agonist D-Trp-6-LHRH. In addition, the adrenocorticotropic hormone (ACTH)-stimulated adrenal response and the thyrotropin releasing hormone (TRH)-stimulated prolactin (PRL) response observed in the patients treated with nilutamide were compared with a control group of healthy age-matched controls. No significant variation in the basal concentrations of adrenal androgens occurred either within or between both treatment groups. In response to ACTH, a decreased 17-α hydroxyprogesterone (17-OHP) accumulation and an augmented A/17-OHP ratio were observed in the antiandrogen group (P < 0.05 for both), suggesting the partial removal of the 17,20 lyase block which was distinctive of the untreated controls, while no significant difference was found for other steroids. Basal PRL levels were not affected by the antiandrogen, but the response to TRH was increased. We conclude that no significant inhibition of adrenal androgen secretion occurs after nilutamide or LHRH agonist treatment. Rather, administration of the antiandrogen alone may partially remove the physiologic decrease in adrenal androgen secretion observed in the elderly. © 1994 Wiley-Liss, Inc.  相似文献   

3.
Objectives: To analyze the clinical effects of flutamide as a second‐line anti‐androgen for combined androgen blockade in patients with castration‐resistant prostate cancer (CRPC) initially treated with bicalutamide as a first‐line anti‐androgen. Methods: Our study population consisted of 16 patients with CRPC who were treated with flutamide (375 mg daily) as second‐line hormonal therapy. Dehydroepiandrosterone (DHEA), androstenedione, androstenediol, testosterone and dihydrotestosterone were measured to investigate the relationship between plasma androgens and outcome following treatment. Furthermore, adrenal androgen levels in a medium of adrenal cancer cell line were also measured. Results: Second‐line hormonal therapy using flutamide resulted in a reduction of the prostate‐specific antigen (PSA) level in 14 (87.5%) of 16 patients. A PSA decline greater than 50% was observed in 8 (50%) of the 16 patients. The duration of median responsiveness was 6.25 months. PSA elevation of baseline androstenediol level was a predictive factor of PSA responsiveness. The lower DHEA group improved the duration of responsiveness to flutamide. In vitro, 3 µmol/L flutamide suppressed DHEA, androstenedione and androstenediol synthesis compared with bicalutamide in a medium of adrenal cancer cell line. Conclusions: Our data show that flutamide suppresses the adrenal androgens in comparison with bicalutamide. The responsiveness and response duration of flutamide can be predicted in patients with a higher baseline androstenediol level and a lower DHEA level. Metabolites from adrenal androgens contribute to the progression of prostate cancer.  相似文献   

4.
Bone metastasis is a complication of prostate cancer in up to 90% of men afflicted with advanced disease. Therapies that reduce androgen exposure remain at the forefront of treatment. However, most prostate cancers transition to a state whereby reducing testicular androgen action becomes ineffective. A common mechanism of this transition is intratumoral production of testosterone (T) using the adrenal androgen precursor dehydroepiandrosterone (DHEA) through enzymatic conversion by 3β- and 17β-hydroxysteroid dehydrogenases (3βHSD and 17βHSD). Given the ability of prostate cancer to form blastic metastases in bone, we hypothesized that osteoblasts might be a source of androgen synthesis. RNA expression analyses of murine osteoblasts and human bone confirmed that at least one 3βHSD and 17βHSD enzyme isoform was expressed, suggesting that osteoblasts are capable of generating androgens from adrenal DHEA. Murine osteoblasts were treated with 100 nM and 1 μM DHEA or vehicle control. Conditioned media from these osteoblasts were assayed for intermediate and active androgens by liquid chromatography–tandem mass spectrometry. As DHEA was consumed, the androgen intermediates androstenediol and androstenedione were generated and subsequently converted to T. Conditioned media of DHEA-treated osteoblasts increased androgen receptor (AR) signaling, prostate-specific antigen (PSA) production, and cell numbers of the androgen-sensitive prostate cancer cell lines C4-2B and LNCaP. DHEA did not induce AR signaling in osteoblasts despite AR expression in this cell type. We describe an unreported function of osteoblasts as a source of T that is especially relevant during androgen-responsive metastatic prostate cancer invasion into bone. © 2021 American Society for Bone and Mineral Research (ASBMR). This article has been contributed to by US Government employees and their work is in the public domain in the USA.  相似文献   

5.
Summary Adrenal androgens are discussed as a reason for tumor progression after androgen ablation therapy. Because of the difference in the secretion of androgens by the adrenals of humans and rats, there is no reliable tumor model to study the role of adrenal androgens in tumor progression. Therefore, the main adrenal androgens were administered to rats in order to mimic human endocrine conditions. Application of dehydroepiandrosteron-sulfate (DHEA-S) alone or a mixture of androstendione (A), 11-hydroxyandrostendione (OHA), dehydroepiandrosterone (DHEA), and its sulfate (DHEA-S) to castrated rats caused only a slight increase of prostate and seminal vesicle weights. Contrary to these findings, growth of the R3327 prostatic carcinoma in castrated rats was greatly stimulated by these adrenal androgens up to the level of the intact control. Thus, in spite of androgen ablation, tumor progression could be induced by exogenous adrenal androgens.  相似文献   

6.
Adrenal steroids in human prostatic cancer cell lines   总被引:5,自引:0,他引:5  
  相似文献   

7.
Delayed puberty in males with chronic renal failure   总被引:1,自引:0,他引:1  
The effects of chronic renal failure on the pituitary-testicular axis of 31 males, aged 11.7 to 20.0 yr (mean, 16.0 yr) were studied. Nine patients not on hemodialysis (group I) had serum creatinines between 2.5 and 8.0 mg/dl, 10 patients were on hemodialysis (group II) and 12 patients had received a renal transplant (group III). The Tanner stage of pubertal development was delayed relative to chronologic age. Testosterone (T), delta 4-androstenedione (delta 4), and urinary 17-keto steroids were normal when related to pubertal stage in groups I and II; and dehydroepiandrosterone (DHEA) and DHEA sulfate (DS) were in the low normal range. In group III, adrenal androgens (delta 4, DHEA, DS) were decreased as a consequence of prednisone therapy whereas T was normal. Luteinizing hormone levels were normal in all. Follicle-stimulating hormone levels were normal in all. Follicle-stimulating hormone (FSH) was significantly increased in groups I and II. In group III, FSH was normal in 6 of 9 patients with serum creatinine concentrations < 2 mg/dl. FSH levels were uniformly elevated in Tanner I-V patients with creatinines > 2 mg/dl. The data shows that FSH is elevated in patients with chronic renal failure even in prepuberty and early adolescence. This may reflect damage to germinal epithelium prior to the advent of spermatogenesis, whereas Leydig cell function appears to remain intact.  相似文献   

8.
In this study evolution of plasma androgen levels in patients with advanced prostatic carcinoma, treated by either subtotal bilateral orchiectomy or estrogens, was studied in order to determine whether subcapsular orchiectomy results in complete elimination of testicular testosterone secretion and whether in subsequent months there occurs any reactivation of eventually remaining Leydig or increased adrenal androgen secretion. This study, performed on 40 patients having undergone bilateral subcapsular orchiectomy for prostatic carcinoma, shows that this intervention results in testosterone levels in the female range and that during the year following subcapsular orchiectomy there is no evidence for reactivation of Leydig cells or for increased adrenal androgen secretion as evaluated from plasma testosterone, androstenedione, and dehydroepiandrosterone sulphate levels. In patients treated with estrogens we found no evidence for stimulation of adrenal androgen secretion, whereas in neither group of patients with prostatic carcinoma we found evidence for increased androgen levels at the time of recurrence of the carcinoma.  相似文献   

9.
The physiological role of dehydroepiandrosterone (DHEA) and DHEA sulphate (DHEAS) is poorly understood. It depends in a large part on their transformation into testosterone and estradiol. The capacity of DHEA as a neurosteroid, the recent discovery of putative specific DHEA receptors on endothelial and vascular smooth muscle cells, the steady decrease of DHEA production from the 40s on, together with certain human epidemiologic data as well as various beneficial effects of DHA supplementation in rodents have suggested the possibility that this steroid is involved in cognitive and memory, metabolic and vascular, immune and sexual functions and in their aging. However, epidemiologic studies are conflicting, and no well-designed clinical trials have definitely substantiated the role of DHEA in these functions in humans, or the utility and safety of DHEA supplementation. However, beneficial effects seem plausible in women with several conditions according to the results of double-blind placebo-controlled trials: the dose of 30 to 50 mg seems beneficial to the mood, sense of well being and sexual desire and activity of women with adrenal insufficiency. The only long-term trial of supplementation devoted to women over 60 reported significant increases in bone mineral density and, in the 70–79-year-old subgroup, in sexual desire, arousal, activity and satisfaction. The dose of 200 mg also proved to decrease disease activity in systemic lupus erythematosus. Lastly, high DHEA doses have improved mood in various groups of patients of any age and gender with depressive symptoms. The use of DHEA therapy may also be discussed in women of any age when a trial of androgen supplementation seems justified because of the existence of an inhibited sexual desire or a sexual arousal disorder associated with documented androgen deficiency. The rather weak conversion of DHEA into testosterone protects from the risk of overdosing associated with testosterone preparations. However, it must be realized that DHEA is also converted into estradiol, which may be a risk factor for breast or endometrial cancer in postmenopausal women. Unlike women, no consistent beneficial effect has been found for men in the placebo-controlled trials. The present data do not exclude a role of DHEA in other conditions, but this remains to be properly established. This paper includes practical considerations on dosage to be used, contraindications and follow-up.  相似文献   

10.
Reactive oxygen species (ROS) can play an important role in the pathogenesis of ischemia-reperfusion (I/R) injury. Dehydroepiandrosterone (DHEA) is one of the hormones secreted from adrenal glands, and in some studies it has been shown that DHEA has antioxidant properties. This experimental study was designed to determine the effect of DHEA on I/R-induced oxidative stress in rabbit kidney. Twenty-one rabbits were divided into three groups. Rabbits were subjected to 60 min of left renal pedicle occlusion followed by 24 h of reperfusion. DHEA (50 mg/kg) (I/R + DHEA group) or equal volume of vehicle (I/R group) was administered 3 h prior to ischemia. The control group received only laparotomy without I/R, DHEA or vehicle. At the end of the reperfusion periods, rabbits were decapitated. Renal tissues were taken for determination of malondialdehyde (MDA) levels as an indicator of lipid peroxidation and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) activities as antioxidant enzymes. In the I/R group, while renal SOD and CAT activities were significantly lower, MDA levels were significantly higher than in the I/R + DHEA group and controls. In the I/R + DHEA group, enzyme activities and MDA levels were similar to the controls. There was no significant difference in terms of renal GPX activity among the groups. DHEA may have a beneficial effect on renal tissue against oxidative damage due to I/R by preventing decreases in some antioxidant enzyme activities.  相似文献   

11.
Based on the analysis of a RX-ray study and a selective blood test for the activity of the plasma renin, aldesterone, hydrocortisone and adrenocorticotropic hormone (ACTH) in 57 patients with arterial hypertension--14 persons without renal failure, 14 ones regularly treated by hemodialysis, 29 patients with left orthostatic varicocele--the authors demonstrated the impact of the renal arterio- and phlebography on the hormone levels studied. Arteriography resulted in an increase in the absolute value of the renal vein renin mean 2.1-fold, aldosterone, 3.3-fold and hydrocortisone, 1.7-fold. A 2.2-fold increase in the renin activity and a 2.6-fold increase in the levels of aldosterone and hydrocortisone noted in all the patients were the result of retrograde renal phlebography. No correlations were established between the changes in hormone levels and the central mechanism of the secretion regulation (ACTH). Radiopaque investigations of the patients with arterial hypertension gave 22 per cent of false positive results with regard to the site of renin secretion and 18 per cent of those with regard to the participation of the studied kidney in renin secretion. The authors supposed a possible regulation of adrenal mineralocorticoid performance by a retrograde blood flow appeared through the adrenal central veins that was induced by phlebography--related elevation of blood pressure in the renal vein.  相似文献   

12.
The adrenal glands produce glucocorticoids (approximately 25 mg cortisol/day), mineralocorticoids (approximately 100 micrograms aldosterone/day) and androgens (e.g. dehydroepiandrosterone = DHEA approximately 10 mg/day) in their cortex and catecholamines in their medulla. Excessive cortisol production leads to Cushing's syndrome. In approximately 2/3 of the cases this is due to ACTH oversecretion most often from a pituitary adenoma and can be cured by removal of this adenoma. Cushing's syndrome caused by an adrenal adenoma, carcinoma or bilateral nodular adrenal hyperplasia is treated by adrenal surgery. Nelson's syndrome consists of hyperpigmentation of the skin and an often aggressively growing pituitary adenoma which secretes excessive amounts of ACTH. Treatment is surgical. Conn's syndrome (primary hyperaldosteronism) is due to aldosterone hypersecretion most often from an adrenal adenoma (therapy: unilateral adrenalectomy), more seldom from bilaterally hyperplastic adrenals (therapy: spironolactone). Excessive adrenal androgen secretion is found in the adrenogenital syndrome in which defective cortisol biosynthesis leads to ACTH oversecretion and ACTH-stimulated overproduction of cortisol precursors, some of which are androgens. Treatment consists of glucocorticoids which suppress the ACTH oversecretion. Pheochromocytomas produce excessive amounts of catecholamines and cause hypertension which can be persistent as well as episodic. Therapy consists of adrenalectomy. Malignant tumors of the adrenals have a poor prognosis. Incidentally found adrenal masses ("incidentalomas") are observed at regular intervals if they are small and should be surgically removed if they have a tendency to grow or are large (greater than or equal to 5 cm phi).  相似文献   

13.
This study investigated the association between depressive symptoms in elderly Chinese men and the total testosterone, dehydroepiandrosterone (DHEA), DHEA sulphate (DHEAS), oestradiol and sex hormone-binding globulin (SHBG) levels, and the free androgen index. Cross-sectional data from 1147 community-dwelling elderly men, aged 65 and older, were used. Depressive symptoms were measured using the Chinese Geriatric Depression Scale (GDS). Total testosterone, free testosterone, DHEA, DHEAS, total oestradiol, the free androgen index and SHBG levels were assessed. DHEA was significantly associated with GDS score, and there was a trend towards DHEAS association, but this was not significant (β=-0.110, P=0.015; β=-0.074, P=0.055). However, no association was seen between depressive symptoms and total testosterone levels, free testosterone levels, oestradiol levels or SHBG levels. In terms of the presence of clinically relevant depressive symptoms, there were no statistically significant differences between patients in the lowest quartile of sex steroid hormone levels and those in other quartiles of sex steroid hormone levels. Similarly to Western studies, our study shows that DHEA and DHEAS levels are associated with depressive symptoms.  相似文献   

14.
The mechanisms responsible for renal potassium (K) conservation during dietary potassium deficiency are poorly understood. This study was undertaken to investigate the time course of potassium conservation as well as the roles of distal sodium (Na) delivery, the distal delivery or sodium plus a nonpermeable anion, mineralocorticoid hormone, renal tissue potassium content, and Na-K-ATPase activity in renal potassium conservation. After 72 hours of a low-potassium diet, basal potassium excretion was negligible. After 24 hours, and even more so after 72 hours of potassium restriction, the kaliuretic response to increasing distal delivery of sodium or sodium plus a nonpermeable anion was impaired. After 24 hours of a low-potassium diet, plasma aldosterone levels fell from 180 +/- 25 to 32 +/- 9 pg/ml (P less than 0.001). Mineralocorticoid hormone given in the first 24 hours of a low-potassium diet resulted in a greater potassium loss (1564 +/- 125 muEq) than it did in controls on the same diet not receiving mineralocorticoid hormone (1032 +/- 83 muEq, P less than 0.005). In contrast, after 72 hours of diet, large doses of mineralocorticoid hormone failed to cause a kaliuresis in either anesthetized or conscious rats. After both 24 and 72 hours, outer medullary Na-K-ATPase was increased. At 72 hours, cortical, medullary, and papillary tissue potassium concentrations were significantly depressed. Acute administration of potassium repleted tissue potassium levels and restored basal and saline-stimulated potassium excretion to normal. Although potassium excretion was markedly depressed after 24 hours of the low-potassium diet, 42K microinjection studies of the distal nephron did not suggest any increase in potassium reabsorption. Following 72 hours of diet, potassium reabsorption increased significantly from 26 +/- 2% to 41 +/- 2% (P less than 0.001). We conclude that renal potassium conservation is at first primarily related to a decrease in potassium secretion, which is most likely mediated by falling levels of mineralocorticoid hormone. After 72 hours of the potassium-deficient diet, however, potassium conservation becomes independent of mineralocorticoid hormone, distal delivery of sodium, and Na-K-ATPase. The decreased tissue potassium content appears to be the primary mediator of both the increase in potassium reabsorption by the distal nephron and of renal potassium conservation at this time.  相似文献   

15.
Cheng S  Qian L  Sui Y  He R 《中华外科杂志》1998,36(4):227-229
目的探讨肾上腺性性征异常的诊断、鉴别诊断和治疗,特别是分泌性激素的肾上腺肿瘤的良恶性鉴别诊断和各种先天性肾上腺增生疾病的治疗原则。方法报告1986年~1996年8例先天性肾上腺皮质增生和5例分泌性激素的肾上腺肿瘤的诊治经验。结果先天性肾上腺皮质增生中有3例17α羟化酶缺乏症,肿瘤患者包括2例女性男性化、3例男性女性化肾上腺肿瘤。分泌性激素肾上腺肿瘤均经手术切除。结论分泌性激素的肾上腺皮质肿瘤的重量、直径、DHEA、尿17酮和血性激素水平、CT表现和肿瘤的浸润及转移可作为判断肿瘤良恶性的参考指标。对大体积肾上腺肿瘤首选改良肋缘下切口。先天性肾上腺皮质增生应根据疾病类型而选用不同皮质激素进行治疗,对于17α羟化酶缺乏的病例,儿童期至青春期不宜应用性激素治疗。  相似文献   

16.
Young women with anorexia nervosa (AN) have reduced secretion of dehydroepiandrosterone (DHEA) and estrogen contributing to skeletal deficits. In this randomized, placebo‐controlled trial, we investigated the effects of oral DHEA + combined oral contraceptive (COC) versus placebo on changes in bone geometry in young women with AN. Eighty women with AN, aged 13 to 27 years, received a random, double‐blinded assignment to micronized DHEA (50 mg/day) + COC (20 µg ethinyl estradiol/0.1 mg levonorgestrel) or placebo for 18 months. Measurements of areal bone mineral density (aBMD) at the total hip were obtained by dual‐energy X‐ray absorptiometry at 0, 6, 12, and 18 months. We used the Hip Structural Analysis (HSA) program to determine BMD, cross‐sectional area (CSA), and section modulus at the femoral neck and shaft. Each measurement was expressed as a percentage of the age‐, height‐, and lean mass‐specific mean from an independent sample of healthy adolescent females. Over the 18 months, DHEA + COC led to stabilization in femoral shaft BMD (0.0 ± 0.5% of normal mean for age, height, and lean mass/year) compared with decreases in the placebo group (?1.1 ± 0.5% per year, p = 0.03). Similarly, CSA, section modulus, and cortical thickness improved with treatment. In young women with AN, adrenal and gonadal hormone replacement improved bone health and increased cross‐sectional geometry. Our results indicate that this combination treatment has a beneficial impact on surrogate measures of bone strength, and not only bone density, in young women with AN. © 2014 American Society for Bone and Mineral Research.  相似文献   

17.
Dehydroepiandrosterone (DHEA) is the main adrenal androgen, which mostly exists in a sulfated version (DHEAS). Both DHEA and DHEAS are metabolic intermediates in the biosynthesis of the male sex hormone testosterone. In men, testosterone is involved in the regulation of fertility, libido, and muscle mass and is valuable for the assessment of gonadal, adrenal, and pituitary function and for the diagnosis of hypogonadism. The objective of the present study was to calculate age-specific reference ranges for serum DHEAS and serum testosterone using 1) linear regression and the mean +/- 1.96 standard deviation concept and 2) quantile regression. From the cross-sectional Study of Health in Pomerania a total of 1078 men aged 20-79 years were included in the analyses. Serum DHEAS and testosterone levels were quantified using IMMULITE 2500 immunoassays. Linear and quantile regression were performed to calculate age-specific reference ranges. Both statistical methods generated different results: The reference ranges based on linear regression identified 17 men (1.6%) with DHEAS levels and 45 men (4.2%) with serum testosterone levels outside the reference range. Using quantile regression, 54 men (5.0%) and 50 men (4.6%) with serum DHEAS and testosterone levels outside the range were detected, respectively. The present study established age-specific reference ranges for serum DHEAS and testosterone levels for men. Quantile regression should be preferred to calculate reference ranges; a better concordance with original data is possible because no distribution assumption is required and the robustness against outliers is given.  相似文献   

18.

OBJECTIVE

To characterize the changes in androgen levels in the prostate after castration, as androgens are critical in the progression of prostate cancer after castration, but the time at which the androgen remaining in the prostatic cancer tissue after castration exerts its effects is poorly understood.

MATERIALS AND METHODS

The ventral prostate (VP) in adult male spontaneously hypertensive rats was excised at 2, 4 and 8 h, 1, 2, 4 and 7 days, and 2, 4 and 8 weeks after castration. The dihydrotestosterone (DHT), testosterone, dehydroepiandrosterone (DHEA) and androstenedione (4‐dione) levels in the VP were measured simultaneously using gas chromatography/tandem mass spectrometry.

RESULTS

Within 2 days of castration, the DHT and testosterone levels in the VP decreased sharply, while there were no significant changes in the DHEA or 4‐dione levels. From 2 days to 2 weeks after castration (2–7 days for 4‐dione), there was a sharp peak in tissue androgen levels in the VP (P < 0.05 for all androgens); during the subsequent 6 weeks after castration, all of the tissue DHT, testosterone, DHEA and 4‐dione levels gradually increased with time.

CONCLUSIONS

These data show the changes which occur in androgen levels in rat VP after castration and support the concept that the adrenal glands compensate for the loss of testicular androgen.  相似文献   

19.
Profound and diffuse alterations in the production of gonadal and adrenal androgens as well as growth hormone are associated with aging. To convey this concept more appropriately, partial endocrine deficiency in the aging male (PEDAM) was introduced as a term for the phenomenon of hormonal alterations in the aging male.Hormones responsible for some of the manifestations associated with male aging are testosterone, growth hormone,dehydroepiansdrosterone (DHEA), melatonin, thyroid hormones and leptin. Of these, testosterone has been widely investigated and its beneficial and adverse effects on male bodily systems are relatively well established. However, a serious body of confusion and misunderstandings surrounding the diagnosis, treatment and monitoring of men suspected of having androgen deficiency has been raised. Therefore, it is timely to provide practical criteria for diagnosis and treatment to avoid misconception about the use of testosterone in the aging male. To provide an understanding and information of the issues, the following headings are summarized: (1) Important clinical consideration on testosterone supplementation in the aging male; (2) Asian practical recommendations on testosterone supplementation in the aging male.  相似文献   

20.
It is not known whether local androgen metabolism is involved in the mechanisms underlying the dehydroepiandrosterone (DHEA) administration-induced improvement of bone mineral density (BMD) in an estrogen-deficiency state. The aim of the present study was to clarify whether DHEA administration would improve local androgen metabolism and BMD in cancellous site of tibia of ovariectomized (OVX) rats. Twenty-two female rats, 6 weeks old, were randomized into three groups: sham-operated rats, OVX control rats, and OVX rats that received DHEA treatment. DHEA was administered intraperitoneally at 20 mg/kg body weight for 8 weeks. The concentrations of free testosterone and dihydrotestosterone (DHT) in cancellous site of tibia did not change as a result of ovariectomy, while the DHT concentration increased following DHEA administration. We revealed that DHEA administration improved the reduction of 17β- and 3β-hydroxysteroid dehydrogenases and clearly reversed the reduction of 5α-reductase types 1 and 2 and androgen receptor in the cancellous site of tibia of OVX rats. DHEA administration suppressed estrogen deficiency relative to the decrease in the cancellous BMD, which was positively associated with local DHT concentration. These findings indicate that DHEA administration enhances local bioactive androgen metabolism in the cancellous tibia of young OVX rats, suggesting that local DHT may play a part in the DHEA administration-induced improvement of cancellous BMD.  相似文献   

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