Exercise training fails to prevent glucocorticoid-induced muscle alterations in young growing rats

The aim of this study was to determine the impact of chronic treatment for 8 weeks with hydrocortisone acetate (5 mg kg-1 day-1) on skeletal muscles, and to evaluate whether sprint training can prevent glucocorticoid-induced muscle atrophy better than endurance training. Biochemical, histological and contractile properties were employed to determine the influence of this steroid on skeletal musculature, and the results were compared to pair-weight animals to take into account the influence of corticoids on growth rate. It was found that hydrocortisone acetate treatment results in a stunted growth, adrenal atrophy and depressed plasma corticosterone levels. Mild corticoid-induced losses of muscle mass and protein content (9%-13%) were observed in fast-twitch skeletal muscles. It appeared that the impact of corticoids is strictly directed toward type IIb fibres, which displayed a 12%-18% reduction in cross-sectional areas. No alterations occurred in plantaris contractile speed or tensions properties. Neither endurance training (30 m/min; 90 min/day; 5 days/week) nor sprint training (60 m/min; 15 min/day; 5 days/week) for 8 weeks was able to counteract the effects of corticoids. These data suggest that increased contractile activity, as induced by treadmill running, is not sufficient to counteract the muscular effects of glucocorticoids when administered at a dose of 5 mg kg-1 day-1.

Case of (Y;1) familial translocation

A balanced reciprocal translocation t(1;Y) (q11;q11) was found in an infertile man with severe oligoasthenospermia. The same translocation was found in his father. The role of X-chromosome inactivation during meiosis in a male carrying a Y;autosome translocation is discussed.

Hypercortisolism in septic shock is not suppressible by dexamethasone infusion

OBJECTIVE

To explore the feedback regulation of glucocorticoids on corticotropin secretion in patients with septic and nonseptic circulatory shock.

DESIGN

Prospective study.

SETTING

An intensive care unit of a general hospital.

PATIENTS

Two groups of patients with septic shock (n = 11) or nonseptic shock (n = 7). A control group (n = 20) was also studied.

INTERVENTIONS

Intravenous dexamethasone (1 mg/hr for 4 hrs) suppression test.

MEASUREMENTS

Plasma concentrations of corticotropin-releasing factor, beta-lipotropin, and corticosteroid-binding globulin measured by radioimmunoassays, and plasma cortisol measured by radiocompetition assay; the ratio of cortisol to corticosteroid-binding globulin calculated as the free cortisol index.

MAIN RESULTS

In both groups of patients, the concentrations of plasma cortisol and beta-lipotropin, and the ratio of cortisol to corticosteroid-binding globulin, were higher than normal subjects (p < .001) and were not different between septic and nonseptic shock patients, whereas the plasma corticosteroid-binding globulin concentration was significantly (p < .001) lower in septic shock patients than in normal subjects (444 +/- 154 vs. 696 +/- 56 nmol/L [22.0 +/- 7.6 vs. 34.5 +/- 2.8 mg/L]), but not significantly lower in nonseptic shock patients (607 +/- 157 nmol/L [30.0 +/- 7.8 mg/L]). In contrast to the complete suppressive effect of dexamethasone infusion on cortisol and beta-lipotropin concentrations in normal subjects, dexamethasone did not suppress cortisol or lipotropin in either septic or nonseptic shock patients.

CONCLUSIONS

During circulatory shock, hypercortisolism is associated with high concentrations of lipotropin, and is not suppressible by intravenous dexamethasone infusion.

[Hyperandrogenism in hirsute and obese women. Effects of a low calorie diet]

To investigate the relationship between overweight and hyperandrogenism, a 1500 kcal/day diet was prescribed for 4 months to 23 hirsute and obese patients. This diet decreased body mass index from 29.9 +/- 4.9 to 27.2 +/- 4.4 kg/m2 (P < 0.008), but had no significant effect on fasting insulin levels (18.9 +/- 14.2 vs. 21.1 +/- 9.6 mlU/l). Weight lost increased significantly (P < 0.008) the plasma concentration of sex-hormone binding-globulin (SHBG) from 21.2 +/- 10.6 to 26.2 +/- 13.5 nmol/l and decreased significantly (P < 0.04) the SHBG-unbound testosterone concentration from 9.3 +/- 6.2 to 7.2 +/- 4.8 ng/dl, without changing the concentrations of the main androgens measured in this study. Moreover, during diet 5 patients in amenorrhea and 8 among 13 patients with irregular menstrual cycle recovered regular menses. We concluded that the control of excess body weight in hirsute women is effective but not sufficient to improve hyperandrogenism.

Glucocorticoid receptors in lymphocytes in anorexia nervosa

OBJECTIVE

The aim was to explore the down-regulation of the glucocorticoid receptors during hypercortisolaemia in anorexia nervosa.

DESIGN

Urine and plasma samples were obtained for cortisol determination and blood lymphocytes were isolated for receptor binding studies.

PATIENTS

Sixteen anorexic patients, aged 16-27 years, with a mean +/- SEM body mass index of 14.2 +/- 2.0 (ranging from 11.1 to 17.4), and 15 normal women were studied. Six patients were reinvestigated after a significant weight gain.

MEASUREMENTS

The binding capacity and affinity of the glucocorticoid receptors were measured with dexamethasone as ligand on lymphocytes.

RESULTS

In patients, both total and free plasma cortisol concentrations were higher than in the normal women, as was their urinary free cortisol; the number of glucocorticoid receptors per cell (Ro) and the binding affinity (Kd) for dexamethasone were, however, not significantly different (Ro: 7687 +/- 1750 vs 7347 +/- 1285 sites/cell; Kd: 7.7 +/- 2.4 vs 7.4 +/- 1.7 nM at 24 degrees C). After weight gain (14 +/- 2 to 16 +/- 2 kg/m2), receptor numbers were 8421 +/- 2126 (pre) and 9011 +/- 500 (post) sites/cell, which are not significantly different (P greater than 0.2); the Kd was unchanged (9.3 +/- 2.6 vs 9.2 +/- 2.4 nM). CONCLUSIONS Hypercortisolaemia does not down-regulate the lymphocyte glucocorticoid receptors in anorexia nervosa and a post-receptor defect might be involved in peripheral tissue resistance to the effects of glucocorticoid hormones in undernutrition.

Pathophysiology of sex hormone binding globulin (SHBG): relation to insulin

In humans, the plasma level of sex hormone binding globulin (SHBG) is regulated by several hormones. We have now accumulated evidence that SHBG is also intimately related to nutritional state. However, we do not yet know what specific signal, if any, may be the regulator of SHBG. There is a strong and negative correlation between fasting insulin level and SHBG in obese as in hyperandrogenic women. Under such circumstances, a high fasting insulin level, normal glycemia and a low SHBG level suggest insulin resistance in terms of glucose disposal but not in terms of SHBG inhibition. This is a rather complex situation. It is too early to judge the importance of IGF-I in the regulation of SHBG. But it may turn out that IGF-I is the main regulator of SHBG and that, by interaction with the IGF-I receptors, insulin carries on its inhibitory activity on SHBG.

[Treatment of hirsutism with spironolactone and progestagen combination]

The antiandrogenic activity of spironolactone was used for treating hirsutism in 76 women, 29 of whom also had acne. Midcycle vaginal bleeding was observed in 21 patients under spironolactone 75 mg per day. This side-effect disappeared after a progestagen administered 10 days each month was added to the treatment. With this combination, spironolactone was well tolerated and effective in treating acne within the first months of administration, but in 61 percent of the patients at least 6 months were required to improve hirsutism.

Rapid escape of cortisol from suppression in response to i.v. dexamethasone in anorexia nervosa

The suppressive effect of dexamethasone (Dex) on plasma cortisol and beta-lipotrophin (beta LPH) was investigated in patients with anorexia nervosa. Dex was given either orally, 1 mg at 2400 h, with blood sampling at 0800 h on the days before and after Dex, or by i.v. infusion starting at 1100 h (1 mg/h) for 4 h with sampling at 0800, 1100, 1500, 2000 and 2400 h and at 0800 h the following day. The plasma cortisol and beta LPH levels during oral or i.v. Dex administration were compared between patients and normally menstruating women of normal weight. The results showed that Dex administration depressed cortisol significantly (P less than 0.0001) during oral or i.v. infusion in most patients, without, however, suppressing it entirely as is the case in normal women. Moreover, during i.v. Dex infusion, the concentrations of cortisol escaped suppression and were higher than in normal women (less than 50 nmol/l) by 0800 h on the day following infusion. In the patients who were reinvestigated after re-feeding and weight gain (n = 9), a normal suppression of cortisol in response to i.v. Dex infusion was observed in only five cases and a slight failure to suppress, although concentrations were lower than before refeeding, was still evident in four. We concluded that, in anorexia nervosa, cortisol concentration rapidly escapes suppression by Dex administration, and that this escape is not related to the degree of starvation.

[Hyperandrogenism in premenopausal women]

Androgens are a family of steroids hormones secreted by the adrenal glands and the ovaries in women. The adrenal secretion of androgens becomes significant around the age of 7, at the onset of adrenal activity, and increases until ovarian puberty. The excess of adrenal androgens, of which the main products are dehydroepiandrosterone and its ester sulfate (DHEAS), is unrelated to a classic deficiency of steroid biosynthesis. Blocking with small doses of dexamethasone (0.5 then 0.25 mg at night), demonstrates that the DHEAS may be blocked and rules out a tumor of the adrenal cortex. This treatment, which presents tolerance problems, is effective on acne, but ineffective on hirsutism which requires the use of antiandrogens. In addition to this idiopathic adrenal hyperandrogenism, the late manifestations of a congenital deficiency in 21-hydroxylase in a clinical picture varying from a mere obesity to moderate hirsutism, but may evolve to a syndrome of polycystic ovaries, is easy to diagnose with a basic 17-hydroxyprogesterone assay. In this case, adrenal blocking by dexamethasone often gives a spectacular clinical result. Isolated ovarian hyperandrogenism, is found in the various clinical forms of the polycystic ovaries syndrome. Usually, this syndrome is suggested by the anovulation, cause of sterility, hirsutism and overweight. Ovarian ultrasonography is often difficult to explain, particularly because of the non-univocal macroscopic appearance of the ovaries. Therefore, a great deal of emphasis is placed on the hormonal exploration which shows an elevated concentration of serum testosterone (T) and mostly of delta-4 androstenedione (A), combined with an elevated luteinizing hormone (LH) which should be determined on several successive samples.(ABSTRACT TRUNCATED AT 250 WORDS)

Decreased immunoreactivity and binding activity of corticosteroid-binding globulin in serum in septic shock

To investigate the mechanism(s) responsible for the depletion of corticosteroid-binding globulin (CBG) activity in serum in septic shock, we developed a radioimmunoassay (RIA) for human CBG, using a monospecific antiserum to human CBG raised in rabbits. CBG was purified from pooled human serum by precipitation with ammonium sulfate and successive affinity chromatography treatments on corticosterone-Sepharose and concanavalin A-Sepharose. Final purification was achieved by HPLC on a diethylaminoethyl-PW (polymer matrix) ion-exchange column. Typical standard curves established for the CBG immunoassay showed parallelism for pure CBG and serial dilutions of sera from patients with septic or nonseptic shock and from healthy controls. Measurements of CBG by RIA showed a significantly (P less than 0.001) lower CBG concentration in patients with septic shock (22.9 +/- 5.9 mg/L, mean +/- SD; n = 23) than in controls (39.9 +/- 6.5 mg/L, n = 21) or in patients with nonseptic shock (33.3 +/- 6.5 mg/L, n = 12). The correlation between the concentrations determined by RIA and the CBG binding capacity was significant (r = 0.619, P less than 0.001, n = 33). The electrophoretic mobility of CBG was similar in sera from septic shock patients and normal subjects (Rf = 0.52-0.56). This suggests that the depletion of the corticosteroid-binding activity in serum during septic shock is associated with a decreased amount of CBG.

Radioimmunoassay of testosterone not bound to sex-steroid-binding protein in plasma

To measure the concentration of testosterone (T) that is not bound to sex-steroid-binding protein (SBP) in plasma, we quantified by radioimmunoassay the T in the supernates of plasma samples after precipitation with 50%-saturated ammonium sulfate. The concentrations of non-SBP-bound T. directly measured with this assay, correlated significantly (P less than 0.001) with those deduced from measurement of the percentage of non-SBP-bound T determined with [3H]T as tracer or from mathematical models according to the law of mass action. It also correlated significantly with the ratio of T to SBP and with the concentration of nonbound T. As determined with this assay, the mean concentration of non-SBP-bound T in normal men was higher in young (4.67, SD 2.68 nmol/L; n = 30) than in older (greater than 40 years) subjects (2.48, SD 1.61 nmol/L; n = 35; P less than 0.001) and lower than normal in hyperthyroid (1.61, SD 0.91 nmol/L; P less than 0.01) or infertile men (3.28, SD 1.70 nmol/L; P less than 0.01). In women, non-SBP-bound T was higher in hirsute patients (0.24, SD 0.11 nmol/L; P less than 0.01) and was lower during pregnancy (0.09, SD 0.05 nmol/L; P less than 0.05) than in normal women during the follicular phase (0.16, SD 0.07 nmol/L). We conclude that this direct measurement of non-SBP-bound T in plasma is suitable for routine use and represents a reliable index of androgenicity in human pathology, particularly when alterations of the binding capacity of SBP modify the concentrations of total T.

Decreased immunoreactivity and binding activity of corticosteroid-binding globulin in serum in septic shock

To investigate the mechanism(s) responsible for the depletion of corticosteroid-binding globulin (CBG) activity in serum in septic shock, we developed a radioimmunoassay (RIA) for human CBG, using a monospecific antiserum to human CBG raised in rabbits. CBG was purified from pooled human serum by precipitation with ammonium sulfate and successive affinity chromatography treatments on corticosterone-Sepharose and concanavalin A-Sepharose. Final purification was achieved by HPLC on a diethylaminoethyl-PW (polymer matrix) ion-exchange column. Typical standard curves established for the CBG immunoassay showed parallelism for pure CBG and serial dilutions of sera from patients with septic or nonseptic shock and from healthy controls. Measurements of CBG by RIA showed a significantly (P less than 0.001) lower CBG concentration in patients with septic shock (22.9 +/- 5.9 mg/L, mean +/- SD; n = 23) than in controls (39.9 +/- 6.5 mg/L, n = 21) or in patients with nonseptic shock (33.3 +/- 6.5 mg/L, n = 12). The correlation between the concentrations determined by RIA and the CBG binding capacity was significant (r = 0.619, P less than 0.001, n = 33). The electrophoretic mobility of CBG was similar in sera from septic shock patients and normal subjects (Rf = 0.52-0.56). This suggests that the depletion of the corticosteroid-binding activity in serum during septic shock is associated with a decreased amount of CBG.

Radioimmunoassay of testosterone not bound to sex-steroid-binding protein in plasma

To measure the concentration of testosterone (T) that is not bound to sex-steroid-binding protein (SBP) in plasma, we quantified by radioimmunoassay the T in the supernates of plasma samples after precipitation with 50%-saturated ammonium sulfate. The concentrations of non-SBP-bound T. directly measured with this assay, correlated significantly (P less than 0.001) with those deduced from measurement of the percentage of non-SBP-bound T determined with [3H]T as tracer or from mathematical models according to the law of mass action. It also correlated significantly with the ratio of T to SBP and with the concentration of nonbound T. As determined with this assay, the mean concentration of non-SBP-bound T in normal men was higher in young (4.67, SD 2.68 nmol/L; n = 30) than in older (greater than 40 years) subjects (2.48, SD 1.61 nmol/L; n = 35; P less than 0.001) and lower than normal in hyperthyroid (1.61, SD 0.91 nmol/L; P less than 0.01) or infertile men (3.28, SD 1.70 nmol/L; P less than 0.01). In women, non-SBP-bound T was higher in hirsute patients (0.24, SD 0.11 nmol/L; P less than 0.01) and was lower during pregnancy (0.09, SD 0.05 nmol/L; P less than 0.05) than in normal women during the follicular phase (0.16, SD 0.07 nmol/L). We conclude that this direct measurement of non-SBP-bound T in plasma is suitable for routine use and represents a reliable index of androgenicity in human pathology, particularly when alterations of the binding capacity of SBP modify the concentrations of total T.

[Available anti-androgens for treating skin hyperandrogenism]

Several antiandrogens compounds are available in the treatment of acne and hirsutism in women. Cyproterone acetate is the most effective antiandrogen. Its use must prevent the occurrence of amenorrhea with the prescription of an appropriate estrogen. Spironolactone, less effective, is better tolerated on a long-term basis, if precaution is taken to combine it sequentially with a progesterone or a norprogesterone, in order to avoid the occurrence of short cycles. This is the treatment of choice of moderate hirsutism or acne, in young patients. The association of spironolactone with an estroprogestative without nortestosterone is easy to use and well tolerated, and gives good results on acne and hirsutism.

[Mechanism of action and peripheral metabolism of androgens in women]

Androgens are steroids with 19 carbon atoms located in the biosynthesis chain between progestives and estrogens. The main androgen is testosterone which is mostly the peripheral interconversion product of delta-4-androstenedione whose origin is mixed, from the ovary and the cortex of the adrenals. Dehydroepi-androsterone essentially comes from the adrenals and is accumulated in the form of a sulfate, the DHEAS, which is one the most concentrated circulating steroid. Although DHEAS only has a slight androgenic activity, the possibility of conversion into testosterone in certain target tissues, especially the skin, makes DHEAS a potential androgen to consider in testing and treating hyperandrogenic conditions. The circulating testosterone is, for the most part, bound to proteins and especially a protein having a strong affinity for testosterone and estradiol, the testosterone estradiol binding-protein (TeBG) or sex steroid binding-protein (SBP). The SBP originating from the liver is under the influence of numerous hormonal and non-hormonal parameters. Androgens decrease the binding ability of SBP, SBP modifies the metabolic clearance of the hormones it binds. Thus, measurement of the free testosterone fraction, not protein-bound, is a better index of the production of testosterone than the measurement of its total concentration. In addition, the fraction which is not bound to the SBP of testosterone is considered as the biologically active fraction, and has a good diagnostic value in the determination of a hyperandrogenic condition. In several target organs, testosterone, under the effect of 5 alpha-reductase, an enzyme whose activity is induced by androgens, is transformed in dihydrotestosterone of DHT which has more binding affinity for androgen receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

Hyperthyroidism due to selective pituitary resistance to thyroid hormones in a 15-month-old boy: efficacy of D-thyroxine therapy

A 15-month-old boy had clinical features of hyperthyroidism. In spite of elevated serum thyroid hormone levels (mean serum T4, 230 nmol/L; T3, 4.2 nmol/L), serum TSH levels ranged between 3.3-5.6 mU/L and rose to 35.4 mU/L after TRH stimulation. There was no abnormal serum thyroid hormone binding or any evidence of a pituitary tumor. The boy was treated with carbimazole for 6 months and became euthyroid. However, his thyroid size enlarged, and serum TSH rose to 45 mU/L. In an attempt to suppress TSH secretion, 3,5,3'-triiodothyroacetic acid was added to carbimazole in daily doses from 0.7-1.4 mg. This combined therapy failed to suppress TSH secretion (serum TSH, 10.2 mU/L) and led to recurrence of symptoms of hyperthyroidism. A trial using highly purified dextrothyroxine (contamination by L-T4, 0.05%) as sole therapy then was carried out. Serum TSH levels promptly declined to normal, both basally and after TRH stimulation (basal, 2.4 mU/L; peak, 13.8 mU/L). During a 24-month follow-up period, the boy remained euthyroid. Serum TSH levels remained in the normal range, as did his serum L-T4 levels (93 nmol/L). Complete remission was achieved using a 5-mg daily dose of D-T4. Temporary discontinuation of D-T4 led to prompt relapse of hyperthyroidism. Our patient's TSH hypersecretion appears to be due to selective pituitary resistance to thyroid hormones. Purified D-T4 effectively inhibited TSH secretion in this patient, without inducing significant side-effects, even when the daily dose was high. The cause of partial pituitary unresponsiveness to thyroid hormones is not known. We suggest that transport of thyroid hormones into the thyrotroph cells could be deficient in our patient.

Lasting remissions in patients treated for Graves' hyperthyroidism with propranolol alone: a pattern of spontaneous evolution of the disease

Twenty-six patients with Graves' hyperthyroidism treated only with propranolol for 1-21 months have been followed up to 5 years. The patients were evaluated before treatment, at 15, 30, and 90 days during treatment, and then at 90-day intervals during propranolol treatment by clinical examination and measurement of serum free T3, free T4, rT3, TSH, and sex hormone-binding globulin concentrations and serum anti-thyroglobulin, antithyroid microsomal, antithyroid peroxidase, and thyroid-stimulating autoantibodies. Eighteen patients who had no biochemical improvement during propranolol therapy or relapsed after initial improvement were treated conventionally. In contrast, eight patients had a biochemical remission, which has lasted 30-48 months after propranolol withdrawal. The biochemical values before and during treatment did not differ among the two groups of patients, except for the initial serum free T3 levels which were significantly higher in the patients who had no remission. Serum TSH levels returned to normal only in patients who had a long-lasting remission. While thyroid autoantibodies decreased or disappeared during follow-up, the evolution of thyroid-stimulating autoantibody values was grossly related to the clinical outcome. Long-lasting remissions may occur in patients with hyperthyroidism due to Graves' disease not given ablative or antithyroid drug therapy. Since propranolol is devoid of antithyroid and immunosuppressive actions, these remissions are probably spontaneous. Although they tended to occur in patients with less severe disease, no biological parameter was found that predicted the outcome.

Sex steroid-binding protein in nonendocrine diseases

In humans, sex steroid-binding protein (SBP) is a protein from the liver which binds with high affinity sex steroid hormones. The plasma concentration of SBP is regulated in part by hormonal factors. It has been shown that estrogens and/or thyroid hormones increase the production of SBP by hepatoma cell lines. It is therefore assumed that the increase in SBP levels in patients given oral estrogens or thyroid hormones is the consequence of a direct stimulation of the liver production of SBP by these hormones. The effects of androgen, progestagen and glucocorticoid hormones are unclear or still a matter of controversy. Moreover, the regulation of the metabolic clearance rate of SBP and the influence of nonhormonal factors on the production of SBP are still speculative. Changes in SBP have been described in a few nonendocrine diseases. A slight hormonal dysfunction may be either the primary or the sole cause of the changes in SBP occurring in these diseases. As an example, elevated SBP levels have been reported in men with liver cirrhosis together with testicular hypofunction and increased estrogen levels. It is therefore difficult to demonstrate that the increase in SBP is due to the liver dysfunction rather than to the endocrinological side effects of cirrhosis. The aim of this review is to present some aspects of the nonhormonal regulation of SBP. There is accumulating evidence in the literature for a relation between SBP levels and body weight and fat distribution, energy balance, diet and physical activity, and lipid metabolism. Therefore, it is tempting to propose that SBP is an index which reflects the status of endocrine, metabolic and nutritional functions. Measurement of SBP may be considered of interest in the light of previous epidemiological studies and the preventive approach to diseases such as hormone dependent tumors, cardiovascular diseases and osteoporosis.

Effects of human chorionic gonadotropin, androgens, adrenocorticotropin hormone, dexamethasone and hyperprolactinemia on plasma sex steroid-binding protein

This presentation reports the effects of androgens, glucocorticoids and some pituitary hormones on plasma sex steroid-binding protein (SBP). The latter was measured by a solid phase method after desteroidation of the plasma. An hCG test (1500 I.U. every other day X 7) was given to 60 boys. In the children with a normal testosterone (T) rise, plasma SBP decreased (% of basal values) either significantly (38.3 +/- 9.3%, group A; n = 29), or moderately (13.4 +/- 4.4%, group B; n = 9) or did not change (-1.6 +/- 6.4%, group C; n = 10). In the 3 infants tested at an age when SBP normally rise sharply, hCG partially prevented this rise. The administration of either fluoxymesterone (10 mg/m2 for 10 days) or depot-T (4 I.M. injections of 100 mg/m2 every 2 weeks) induced a significant drop (about 2-fold) in plasma SBP in a control group of infants or children, but did not change SBP in 3 infants with the androgen insensitivity syndrome. A single injection of 0.25 mg of ACTH did not significantly alter SBP levels. In contrast, at the end of a 3-day ACTH test (0.5 mg/m2 12 hourly X 6) SBP levels had significantly decreased (mean 35% fall) with no age or sex differences, and with no correlation with the cortisol levels reached. However, the lowering effect of ACTH on SBP levels is likely mediated by glucocorticoids, since its effect was reproduced by high doses (8 mg/day for 3 days) of dexamethasone given at once or after 3 days of treatment at lower dose (20 micrograms/kg BW). It would appear that the depressive effect of ACTH and/or dexamethasone is observed for a threshold dose of glucocorticoids (greater than 5-fold physiological levels) and a certain time (greater than or equal to 3 days) of exposure. The mechanism by which androgens and glucocorticoids lower SBP levels in vivo is not yet understood. From recent experiments, showing that both stimulate the secretion of SBP in hepatoma cells in vitro, it would appear that both hormones may alter SBP metabolism. In a selected population of hyperprolactinemic women, with normal weight and no hirsutism, plasma SBP levels were found in the normal female range. The discrepancy with previous studies in the literature may be explained by differences in the degree of hyperprolactinemia and/or associated hyperandrogenim. This study further documents the multifactorial and intricated hormonal influences involved in the regulation of plasma SBP in vivo.