Insulin, C-peptide, androgens, and beta-endorphin response to oral glucose in patients with polycystic ovary syndrome.

We examined the effects of an oral glucose load on plasma insulin, androgens, and beta-endorphin (beta EP) concentrations in patients carefully selected as having polycystic ovary syndrome (PCOS) and normal glucose tolerance. Our aim was to verify whether insulin resistance is a common feature of PCOS and to differentiate the metabolic abnormalities related to PCOS from those associated with obesity. Plasma immunoreactive insulin (IRI), C-peptide (C-PR), testosterone, androstenedione, dehydroepiandrosterone sulfate, ACTH, and beta EP responses to a 3-h oral glucose tolerance test (OGTT) were evaluated in 10 obese (OB-PCOS) and 10 nonobese (NO-PCOS) patients with PCOS and in 7 obese and 7 nonobese ovulatory controls. OB-PCOS and NO-PCOS did not differ significantly from weight-matched controls in the IRI response, but had a significantly higher C-PR response in terms of mean postglucose load levels and mean incremental areas. During OGTT, mean plasma levels of testosterone, androstenedione, and dehydroepiandrosterone sulfate declined in both PCOS groups as well as in controls, and no significant correlation between the plasma androgen and IRI or C-PR responses was found. The ACTH response in OB-PCOS and NO-PCOS was similar to that in controls, with a progressive decrease until 180 min. A similar decline in plasma beta EP was found in controls, whereas no change in plasma beta EP was observed in OB-PCOS and NO-PCOS. These findings indicate that independently of the presence of obesity, PCOS patients have enhanced insulin secretion in response to OGTT and show a peculiar pattern of changes in plasma beta EP.

Inhibition of heme oxygenase in the central nervous system potentiates endotoxin-induced vasopressin release in the rat.

Previous in vitro studies have shown that increases in endogenous carbon monoxide (CO) generation via activation of the enzyme heme oxygenase (HO) within the rat hypothalamus are associated with the reduced release of the neuropeptides, vasopressin (AVP) and oxytocin, while evidence concerning corticotrophin-releasing hormone (CRH) is controversial. The present study investigated whether there is also a functional relationship between the HO-CO pathway and AVP and corticosterone (Cort) in vivo. Male Wistar rats were challenged with bacterial lipopolysaccharide (LPS) at doses producing significant activation of the hypothalamo-pituitary-adrenal (HPA) axis. LPS was given alone or after pretreatment with the HO inhibitor Sn-protoporphyrin-9 (SnPP9). The latter was injected either intraperitoneally (i.p.) or by intracerebroventricular (i.c.v.) route. SnPP9 given i.p. failed to modify either basal or LPS-stimulated levels of AVP and Cort. On the contrary, i.c.v. SnPP9 strongly potentiated LPS-induced AVP release and significantly enhanced basal serum Cort levels, although it failed to potentiate stimulation by LPS. The LPS + i.c.v. SnPP9 also significantly reduced the hypothalamic stores of AVP compared to controls, correlating with increased circulating levels of AVP. Taken collectively, these data are in concordance with previous in vitro observations showing that the HO-CO pathway acts centrally to attenuate endotoxin-stimulated AVP release, while having less effects on the pituitary-adrenal axis.

Effect of estrogens on luteinizing hormone release in testicular feminization syndrome before and after gonadectomy.

The effect of exogenous estrogens on luteinizing hormone release was studied in three siblings with complete testicular feminization syndrome. Two subjects, 21 and 20 years old, were postpubertal. The third, 15 years old, was in the early pubertal stage. An estrogen provocation test was performed in which 20 mg of conjugated estrogens were administered intravenously and serum follicle-stimulating hormone and luteinizing hormone levels were assessed every 12 hours for 96 hours under basal conditions, on day 5 of an eight-day treatment with 0.2 mg/day ethinyl estradiol orally, and on day 5 of a subsequent eight-day treatment with 0.2 mg/day ethinyl estradiol and 120 mg/day cyproterone acetate orally. The first two tests were repeated one month after gonadectomy. During pregonadectomy treatments there was an overall luteinizing hormone fall. After gonadectomy, the two postpubertal subjects exhibited luteinizing hormone surges during ethinyl estradiol treatment -in one as a single peak and in the other as multiple peaks. A positive feedback effect was not induced in the youngest patient either before or after gonadectomy as in normal prepubertal and early pubertal females. The data suggest that testosterone or some other testicular factor inhibits estrogen induced positive feedback for luteinizing hormone. This inhibition mechanism acts independently of the testosterone cytosol receptor.

Simultaneous determination of free testosterone and testosterone bound to non-sex-hormone-binding globulin by equilibrium dialysis.

We describe a procedure based on equilibrium dialysis that allows the simultaneous determination of free testosterone and testosterone bound to non-sex-hormone-binding globulin (non-SHBG) in plasma. After saturating SHBG with 5 alpha-dihydrotestosterone (DHT) according to a technique recently described, the percentage of free testosterone in the treated and the untreated samples is measured by equilibrium dialysis with use of a semiautomated instrument that allows rigorous standardization of the experimental conditions. The present method is simpler and faster than the previously described technique in which, after the saturation of SHBG with DHT, the unbound fractions were measured by centrifugal ultrafiltration dialysis. The method is also reproducible and suited for the analysis of a large number of samples. The technique has been applied to the determination of the fractional distribution of testosterone in plasma pools from normally menstruating, pregnant, and postmenopausal women and from normal men.

Evaluation of steroid laboratory tests and adrenal gland imaging with radiocholesterol in the aetiological diagnosis of Cushing's syndrome.

Basal values of the urinary excretion of 17-oxogenic steroids and serum levels of cortisol were not satisfactory in the differentiation of 'suspected' subjects from patients with true Cushing's syndrome. With an RIA method for serum cortisol determination, the overnight dexamethasone suppression test provided the most reliable single test in establishing adrenocortical hyperfunction. Thirty-five normal subjects, fifty-nine obese patients, thirteen 'suspected' patients, and thirteen patients with disease states other than Cushing's syndrome had suppressed values below 4.0 microgram/100 ml. None of the ten patients with Cushing's syndrome had a cortisol concentration less than 16.3 microgram/100 ml. Adrenal gland scintigraphy after radiocholesterol injection is a more valuable tool than the metyrapone test and the high-dose dexamethasone suppression test in the localization and differential diagnosis of adrenocortical lesions causing Cushing's syndrome. It obviates the need for angiographic procedure in the localization of adenomas. It is a reliable technique for identifying functioning adrenal remnants. We therefore propose a schedule for studying patients with suspected adrenocortical hyperfunction.

Prolactin secretion and dehydroepiandrosterone sulphate plasma levels in women with benign breast disease.

The purpose of the present investigation was to verify possible positive correlations between prolactin secretion and dehydroepiandrosterone sulphate levels in plasma of women with benign breast disease. Prolactin secretion was evaluated in terms of basal levels, maximum peak, percent increase above baseline levels, total integrated area, response area after TRH stimulation. No correlation was found between the parameters of prolactin secretion and dehydroepiandrosterone sulphate levels.

Successful treatment of ectopic Cushing's syndrome with the long-acting somatostatin analog octreotide.

We report on the efficacy of the long-acting somatostatin analog octreotide in a 43-yr old woman with ectopic ACTH syndrome. Plasma cortisol, ACTH, beta-endorphin (beta-END) and urinary free cortisol (UFC) were elevated (range 743-920 nmol/l, 29.2-49.7 pmol/l, 71.0-84.1 pmol/l, 2117-3119 nmol/day respectively). Ovine CRH (oCRH) and high dose dexamethasone did not affect cortisol and ACTH levels, while UFC significantly decreased after dexamethasone. Initially radiological investigation failed to localize the ACTH secreting tumor. Ketoconazole was not tolerated. Plasma cortisol significantly decreased both after single (100 micrograms sc) (baseline 531 nmol/l, nadir 218 nmol/l) and 3-day octreotide administration (from 810 to 448 nmol/l); plasma ACTH decreased slightly (from 30.4 to 21.3 pmol/l and from 32.4 to 22.5 pmol/l respectively); UFC decreased from 2616 to 711 nmol/day after the 3-day test. Long-term octreotide treatment (100 micrograms/8h per 54 weeks) led to clinical and biochemical improvement and recurrence followed drug withdrawal; no side effects were observed. Six months after octreotide administration a 2 cm lung mass was detected with CT and MR. Surgery was performed and a bronchial carcinoid was removed. Immunoreactive ACTH in the tumor has been demonstrated by histochemistry. Postoperatively a lasting remission of Cushing's syndrome was observed without further therapy.

Endocrine aspects of benign breast disease.

The purpose of this study was to determine the levels of dehydroepiandrosterone sulfate (DHAS) in the plasma of women with benign breast disease (BBD) and in normal subjects. Possible changes in DHAS plasma levels and in its adrenal secretion under adrenocorticotrophin hormone (ACTH) were also investigated in women with BBD before and after bromocriptine therapy. Our results demonstrate that plasma levels of DHAS in women with BBD overlap with those found in controls. Prolactin (PRL) suppression in women with BBD receiving bromocriptine treatment was associated with a significant (p less than 0.02) decrease of baseline DHAS plasma levels and of stimulated ACTH response curve (p less than 0.02). These data suggest a possible relationship between PRL and DHAS secretion in women with BBD.

Hormonal profile in benign breast disease. Endocrine status of cyclical mastalgia patients.

Plasma levels of prolactin, before and after TRH stimulation, progesterone, estradiol, sex-hormone-binding-globulin, androstenedione, testosterone and dehydroepiandrosterone-sulphate were determined in a group of women with benign breast disease and in control group, in order to correlate a possible hormonal disorder to breast pathology. The hormonal pattern in the patients with benign breast disease was characterized by an increased responsiveness of lactotrophes to TRH stimulation and by higher levels of sex hormone binding globulin, probably sustained by an underlying hyperestrogenism.

Dehydroepiandrosterone sulphate plasma levels in normal women and patients with benign breast disease.

Dehydroepiandrosterone sulphate plasma levels were measured in patients with benign breast disease and in healthy women. In addition the adrenal secretion of dehydroepiandrosterone sulphate was assessed by means of an ACTH stimulation test in some patients and control subjects. The results obtained demonstrate that dehydroepiandrosterone sulphate plasma levels of patients with benign breast disease overlap those found in controls and that the adrenal response to ACTH of patients with breast pathology does not differ from that of healthy women.

[Endogenous opiate modulators of insulin secretion in the obese]. / Les opioïdes endogènes modulateurs de la sécrétion d'insuline chez les obèses.

The effects of endogenous opiates on insulin response to oral glucose load were studied in obese subjects and in lean healthy volunteers. None of these having a family diabetes. After 3 days on an 1,800 cal./m2, 40% carbohydrate diet all subjects underwent two standard 75 g oral glucose tolerance tests (OGTT), one of which was accompanied by an i. v. administration of 10 mg of, an antagonist of opiates, the naloxone. In one group of obese impaired oral glucose tolerance test occurred. All obese, but not the lean healthy volunteers, showed: 1) increased basal plasma insulin levels, 2) higher insulin response to OGTT, 3) a decrease in insulin response to OGTT after naloxone administration, with significant differences at 60 min (p less than 0.01) and 90 min (p less than 0.025). In none of the subjects significant differences were observed in blood glucose levels after OGTT plus naloxone administration. These data suggest that increased endogenous opiates may affect insulin response to glucose in obese with impaired or normal oral glucose tolerance test. At present there seems to be no satisfactory explanation for unchanged blood glucose levels during OGTT with and without naloxone despite a decrease in insulin secretion in the obese patients.

Bromocriptine for treatment of benign breast disease. A double-blind clinical trial versus placebo.

Over the last few years bromocriptine has been used for treatment of mastodynia and benign breast disease, but with contradictory results. This double-blind clinical trial was performed to determine the efficacy of this prolactin inhibitor as compared with placebo. Subjective discomfort, clinical examination of the breast lesions, echomammography and breast thermography were evaluated before, during and after 3 months of treatment and in a further follow-up. Plasma levels of estradiol, progesterone and prolactin were measured over the same time. Significant reduction of mastodynia and significant improvement of the breast lesions were observed in the group given bromocriptine, though echomammography and breast thermography did not reveal any significant differences between the two groups. Plasma prolactin levels were significantly reduced by bromocriptine administration.

Effects of ovary suppression by a long-acting GnRH-agonist on circulating GH, insulin-like growth factor I and insulin levels in women with polycystic ovary syndrome.

Our aim was to investigate the effect of GnRH-agonist (GnRH-a) induced suppression of plasma sex steroids on serum GH, insulin like growth factor-I (IGF-I) and insulin levels after an oral glucose load (OGTT) in women with polycystic ovary syndrome (PCOS). Serum insulin, GH and IGF-I levels during a 75-g 4-h OGTT were measured in 3 nonobese and 7 obese hyperandrogenic women with PCOS and normal glucose tolerance before and after 10 weeks of treatment with the GnRH-a triptorelin (3,75 mg im every 28 days). Basal estrogen and androgen levels were also measured at time 0 of the first and the second OGTT. After the therapy serum estrogens and androgens were significantly suppressed. Body weight remained unchanged. Basal GH significantly increased after the treatment while fasting IGF-I and insulin levels decreased from (mean +/- SE) 349.3 +/- 31.8 to 278.7 +/- 33.2 ng/mL and from 22.4 +/- 4.1 to 18.8 +/- 4.4 microU/mL, respectively. The insulin response to OGTT (area under curve) was also reduced (from 16,017 +/- 2598 to 11,736 +/- 2317 microU/mL/240 min). Our results suggest that the GnRH-a induced suppression of ovary secretion may modify the serum GH and IGF-I levels and the insulin response to an OGTT in women with PCOS.

Endocrine status in patients with mammary gland diseases: correlation between steroid hormones and sex steroid binding globulin.

We have studied 131 women affected by benign or malignant breast disease, in order to explore their endocrine status. We evaluated basal concentrations of the following hormones: FSH, LH, PRL, estrone (E1), estradiol (E2), testosterone (T), androstenedione (A), DHEAS and SHBG. Basal hormone levels in these patients were not significantly different from those in normal age-matched subjects. However, in premenopausal women, 31% of patients with benign disease and 34.4% with malignant lumps exhibited an elevated FSH/LH ratio (greater than 1) and lower T levels, compared to those having a normal FSH/LH ratio. The difference in T levels was not coupled with the expected specular variations in SHBG levels. Moreover, in none of the group considered, T concentrations or E2/T were significantly correlated with SHBG levels. These data seem to suggest an altered regulation of SHBG in these patients, in whom the modulation of SHBG by circulating sexual steroids appears to be different when compared with normal subjects.

Calcium antagonists and hormone release. V. Effects of a calcium-antagonist (verapamil) on pituitary hormone release in hypersecretory states.

Twenty-five patients with various syndromes of pituitary hyperfunction, of tumoral and nontumoral origin, were infused with verapamil (VE), a Ca2+-channel blocker (5 mg/h X 3 h) to assess the calcium dependence of the augmented hormone secretion. In 5 hypogonadal women with elevated gonadotropin secretion, VE produced a marked inhibition of LH (54.6%) and FSH (49.4%) release, comparable to that observed in normal subjects who were infused with VE. In 5 patients with latent or mild hypothyroidism, TSH levels decreased during the VE infusion, and the magnitude of the decrease was directly correlated with the basal levels (r = 0.986, p less than 0.01). In patients harboring a pituitary tumor, differential effects of VE infusion were observed: it induced an inhibition (28.5%) of ACTH secretion in patients with Cushing's disease; in acromegalic patients, no alterations in HGH levels were noted; on the contrary, in prolactinoma patients, a clear PRL increment (47.2%) was present. These experiments confirm that the need for extracellular Ca2+ varies from hormone to hormone and that VE infusion can modify the secretion of pituitary hormone in a hypersecretory state, as well as those hormones which are unaffected by VE infusion in basal condition.

Endocrine evaluation of patients with benign lumps of the breast.

We studied 39 women with benign breast disease in order to evaluate their endocrine status. Two groups of women were distinguished: premenopausal (n = 22) and postmenopausal (n = 17). We determined basal concentrations of the following: follicle-stimulating (FSH) hormones, luteinizing hormone (LH), prolactin (PRL), estrone (E1), estradiol (E2), testosterone (T), androstenedione (A), dehydroepiandrosterone sulfate (DHEAS). We also assayed sex hormone-binding globulin (SHBG) and calculated the free androgen index (FAI). The samples in premenopausal subjects were collected in the follicular phase. There was no significant difference between the groups considered and normal control subjects for any of the hormones tested; there was no significant correlation between T concentration or E2/T ratios and SHBG levels; the FAI was not significantly different compared to normal subjects. In conclusion, even if basal steroid, gonadotropin, and SHBG levels do not indicate an unequivocal alteration, it is not possible to exclude subtle alterations in transport and local metabolism of steroids. The balance between steroids and SHBG seems to indicate small dysregulations, which could be of some importance.

Inhibitory action on GHRH-induced GH secretion of chronic tamoxifen treatment in breast cancer.

OBJECTIVE: Previous in vitro and in vivo studies on animal models have demonstrated that tamoxifen (TAM) inhibits GH secretion. Studies in humans are conflicting. The aim of this study was to evaluate the effect of chronic TAM treatment on GH secretory dynamics in the presence of negligible endogenous oestrogens, in postmenopausal women with breast cancer. PATIENTS: Ten female patients were studied over a 6-12-month period after surgical therapy, before medical therapy, and during chronic treatment with TAM (20 mg/day p.o.). MEASUREMENTS: In all subjects we performed a standard GHRH-test (50 mg i.v. as a bolus) and compared the single time points, the peak response and the areas under the curves (AUC), before and during treatment. In basal samples, we evaluated the circulating levels of IGF-1, IGF-BP3 and their ratio, SHBG, FSH, LH, Oestradiol (E2) and PRL. GH was assayed by Immunoradiometric assay (IRMA). Insulin-like growth factor type I (IGF-I), Insulin-like growth factor-binding protein-3 (IGF-BP3), FSH, LH and PRL were measured by Radioimmunoassay (RIA). SHBG was measured by a noncompetitive liquid phase immunoradiometric assay, while E2 was measured directly in plasma by a liquid phase technique. RESULTS: TAM chronic treatment significantly reduced GH response to GHRH at single time point evaluations, GH peak response (mean decrease: 59.8 +/- 7.3%) and GH-AUC (mean decrease 53.8 +/- 8.9%). TAM also significantly reduced plasma IGF-1 levels. No significant variations were found in IGF-BP3 levels or in the IGF-1/IGF-BP3 ratio. A significant inverse correlation between SHBG and IGF-1 circulating levels was noticed during TAM treatment. CONCLUSIONS: Our data show that long-term tamoxifen treatment blocks the response of GH to exogenous GHRH and reduces IGF-1 levels, possibly by a central mechanism other than the demonstrated peripheral action. The results of this study, keeping in mind the demonstrated mitogenic role of IGF-1 in cancer proliferation, can contribute to clarify the mechanism by which TAM exerts its antiproliferative effect.

Hypothalamic derangement in traumatized patients: growth hormone (GH) and prolactin response to thyrotrophin-releasing hormone and GH-releasing hormone.

OBJECTIVE: To study the impact of severe head injury on both basal pituitary hormone secretion and the response to exogenous synthetic hypothalamic releasing factors (TRH and GHRH) in order to evaluate sequential changes in the central control of hypophyseal secretion in the days following head injury. DESIGN: Prospective clinical study PATIENTS: 21 comatose male patients with head injuries, each intubated and ventilated, intensively monitored and having no previous endocrine problems. MEASUREMENTS: AND RESULTS The GH and PRL responses to TRH (200 microg iv), and the GH and PRL responses to GHRH (50 microg iv) were evaluated, respectively, on the days 1 and 16 and on days 2, 7and 15 after admission. Daily blood samples were also collected for GH, PRL, TSH, T3 and T4 evaluation. In the basal samples taken on days 2, 7 and 15, IGF-I and cortisol were also determined. Nitrogen balance was assessed daily. On the day 1, TRH increased GH levels from 9.8 +/- 2.2 to 22.4 +/- 6.5 mU/l but failed to induce GH release on day 16. The PRL response to TRH was normal. The GH peak response to GHRH was normal on the day 2 (35.7 +/- 13.9 mU/l), but was increased on days 7 and 15 (68.3 +/- 10.7 mU/l on day 7; 73.8 +/- 9.2 mU/l on day 15, P < 0.01 vs. day 2). We found a significant PRL response to GHRH during the whole period of observation. In the daily evaluation, nitrogen balance was negative in all patients from the day 1 to 5. On average, all patients reached a positive nitrogen balance on the day 8. Compared to the day 2, a statistical increase in IGF-I concentration was observed on days 7 and 15. CONCLUSIONS: The evaluation of pituitary dynamics in the acute phase of a severe injury demonstrates an alteration of GH and PRL secretion, which correlate with the aminergic and/or peptidergic derangements. Taken together, our data suggest augmented tone of both GHRH and somatostatin in the very acute phase, while an imbalance of releasing factors is hypothesized in the following days. The metabolic consequences of this neuroendocrine pattern could be advantageous in the rapid recovery from the cascade of events produced by the trauma, as documented by the increase in IGF-1 levels and the positive nitrogen balance.