bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of free follistatin levels in sera of normal subjects and patients with various diseases
Authors: Sakamoto Yukihiro , Shintani Yasumi , Harada Kazuyo , Abe Masahiro , Shitsukawa Keiji , Saito Shiro
Published: December 2008

Sakamoto Y. Shintani Y, Harada K, Abe M, Shitsukawa K, Saito S. Determination of free follistatin levels in sera of normal subjects and patients with various diseases. Eur J Endocrinol 1996:135:345–51. ISSN 0804–4643

We developed an assay system for measuring free follistatin by using an anti-follistatin mouse monoclonal antibody and [125I]activin A. The sensitivity of this assay was 0.5 μg/l and crossreactivities with inhibin. luteinizing hormone, follicle-stimulating hormone and growth hormone were all less than 0.5%. The dose-response curves of human sera and follicular fluid were parallel to the standard curve, and the follicular fluid contained a large amount of follistatin (6.4 ± 0.5 mg/l, mean ± SEM; N = 13). The within- and between-assay coefficients of variation calculated from the analysis of serum samples of four different concentrations were 3.3–7.8% and 3.9–11.0%, respectively. The recovery rates of free follistatin at five different doses were 86.4–102.4%. When activin A was added to the same sample, free follistatin recovery rate declined dose-dependently. Gel filtration analyses of human serum and follicular fluid resulted in a single peak corresponding to authentic follistatin. Using this assay, free follistatin concentrations in sera were measured in normal, pregnant and diseased subjects. The free follistatin level in serum of normal adults was 3.5 ± 0.2 μg/l (N = 60), which was significantly elevated in pregnant women (16.7 ± 1.3 μg/l, N = 56), and in patients with chronic liver disease (8.1 ± 1.1 μg/l, N = 20), chronic renal failure (6.7 ± 0.9 μg/l, N = 42), advanced solid cancer (8.5 ± 1.0 μg/l, N = 39) and hematological malignancies (6.8 ± 1.0 μg/l, N = 18). These data indicated that the free follistatin concentration in serum is detectable and varies during pregnancy and in various diseased states.

Yukihiro Sakamoto, First Department of Internal Medicine, School of Medicine, The University of Tokushima, 3-18-15 Kuramoto-cho, Tokushima 770, Japan
Interleukin 10 inhibits insulin release from and nitric oxide production in rat pancreatic islets
Authors: Laffranchi Renato , Spinas Giatgen A
Published: December 2008

Laffranchi R, Spinas GA. Interleukin 10 inhibits insulin release from and nitric oxide production in rat pancreatic islets. Eur J Endocrinol 1996;135:374–8. ISSN 0804–4643

Interleukin 10 was found to prevent cytokine-induced nitric oxide production in murine macrophages. Because, in rat islets, interleukin 1β induces β-cell dysfunction, mainly due to overproduction of nitric oxide, we studied if this effect could be counteracted by interleukin 10. Rat pancreatic islets were cultured for 24 h in the presence or absence of 0.02–20 ng/ml recombinant human interleukin 10. Interleukin 10 dose-dependently inhibited insulin secretion with maximal inhibition (27 ±4%, p < 0.05) at 2 ng/ml without impairment of islet cell viability. However, incubation of pancreatic islets with interleukin 10 resulted in a 61.5% decrease of nitric oxide production. Co-incubation of islets with interleukin 10 (2 ng/ml) and recombinant human interleukin 1β (0.15 ng/ml) resulted in a more pronounced suppression of basal insulin release than with interleukin 1β alone (55 ± 3.6% vs 44 ± 3.6% with interleukin 1β alone, p < 0.05) but did not reduce interleukin 1β-stimulated NO production or reverse the effect of interleukin 1β on cell viability. Thus, in pancreatic islets interleukin 10 is not capable of counteracting the interleukin 1β-induced β-cell dysfunction, but rather enhances the inhibitory effect of interleukin 1β by a different mechanism.

Renato Laffranchi, Division of Endocrinology and Metabolism, Department of Internal Medicine, University Hospital, Rämistrasse 100, CH-8091 Zürich, Switzerland
Effects of gonadotropin-releasing hormone on bioactivity of follicle-stimulating hormone (FSH) and microstructure of FSH, luteinizing hormone and sex hormone-binding globulin in a testosterone-based contraceptive trial: evaluation of responders and non-responders
Authors: Simoni Manuela , Peters Jörg , Behre Hermann M , Kliesch Sabine , Leifke Eckhard , Nieschlag Eberhard
Published: December 2008

Simoni M, Peters J, Behre HM, Kliesch S, Leifke E, Nieschlag E. Effects of gonadotropin-releasing hormone on bioactivity of follicle-stimulating hormone (FSH) and microstructure of FSH. luteinizing hormone and sex hormone-binding globulin in a testosterone-based contraceptive trial: evaluation of responders and non-responders. Eur J Endocrinol 1996;135:433–9. ISSN 0804–4643

Only a proportion of normal men participating in testosterone-based contraceptive trials develop azoospermia (responders). This study analyzed whether serum follicle-stimulating hormone (FSH), luteinizing hormone (LH) and sex hormone-binding globulin (SHBG) are qualitatively different between responders and non-responders. Determination of in vitro bioactive FSH after stimulation with gonadotropin-releasing hormone (GnRH) and analysis of molecular heterogeneity of serum FSH. LH and SHBG was carried out by chromatofocusing and concanavalin-A affinity chromatography in eight men who had participated in a previous contraceptive study with testosterone buciclate. Blood was withdrawn at 15-min intervals on two basal occasions and 30, 45 and 60 min after iv administration of GnRH (100 μg). Pools of sera were separated by chromatofocusing in the pH range 3–6 and by lectin chromatography on concanavalin A. Immunoreactive FSH, LH and SHBG were assayed in the eluates. Bioactive FSH was analyzed by the rat Sertoli cell bioassay. Serum bioactive FSH increased after GnRH stimulation, without significant differences between responders and non-responders. The chromatofocusing profiles of serum FSH showed a significant shift towards the less acidic region after GnRH. The isoform distribution was similar in responders and non-responders. No significant differences were found in the relative proportion of FSH, LH and SHBG retained by concanavalin A. It is concluded that the extent of suppression of sperm production by androgen administration cannot be foreseen either on the basis of the response of bioactive FSH to GnRH administration or from the glycosylation pattern of serum FSH, LH and SHBG.

E Nieschlag, Institute of Reproductive Medicine of the University, Domagkstr. 11, D-48129 Münster, Germany
Presence and localization of endothelin receptor in the rat ovary and its regulation by pituitary gonadotropins
Authors: Otani Hisako , Yamoto Mareo , Fujinaga Hiroyuki , Nakano Ryosuke
Published: December 2008

Otani H, Yamoto M. Fujinaga H, Nakano R. Presence and localization of endothelin receptor in the rat ovary and its regulation by pituitary gonadotropins. Eur J Endocrinol 1996:135:449–54. ISSN 0804–4643

In the present study we examined the regulation of receptors for endothelin 1 (ET-1) in rat granulosa cells. We examined the localization and regulation of ET receptors in immature rat ovary and the effects of ET-1 on steroidogenesis in cultured rat granulosa cells. The ovaries used in autoradiography were derived from pregnant mare serum gonadotropin and human chorionic gonadotropin-treated immature rats. Granulosa cells were obtained from diethylstilbestrol-treated immature rats and incubated with 125I-ET-1. Granulosa cells were cultured with ET-1 in the presence or absence of ovine follicle-stimulating hormone. The concentrations of sex steroid hormones in conditioned media were measured by radioimmunoassay. The binding site for ET-1 was localized in the granulosa cells, but not in thecal and luteal cells. Follicle-stimulating hormone (FSH) induced a dose-dependent increase in specific binding for ET-1 to cultured rat granulosa cells. In contrast. luteinizing hormone (LH) induced a dose-dependent decrease in specific binding for ET-1 to cultured rat granulosa cells. Conversely, treatment with prolactin and several sex steroid hormones had no effects on the specific binding of ET-1. Treatment with ET-1 inhibited FSH-stimulated accumulation of progesterone and estradiol in cultured rat granulosa cells. The results indicate that both FSH and LH influence the expression of ET-1 receptor, and that ET-1 may play a regulatory role in the ontogeny of the granulosa cell.

Ryosuke Nakano, Department of Obstetrics and Gynecology. Wakayama Medical College, 27 Shichibancho, Wakayama, 640, Japan
Rhythmicity of luteinizing hormone secretion expressed in vitro
Authors: Lewy Hadas , Naor Zvi , Ashkenazi Israel E
Published: December 2008

Lewy H, Naor Z, Ashkenazi IE. Rhythmicity of luteinizing hormone secretion expressed in vitro. Eur J Endocrinol 1996;135:455–63. ISSN 0804–4643

In the present study we explored the possibility that the pituitary functions as an autonomous clock and is capable of generating rhythms of luteinizing hormone (LH) release independently of hypothalamic control. Pituitaries from estrous or diestrous day 1 female mice were perifused separately with Medium-199. Effluent samples were collected at 10-min intervals and assayed for LH levels. Fourier analysis and curve-fit analysis served to elucidate the presence of prominent periods whose significance was then determined by best-fit cosinor. The latter method was used to determine additional parameters for the significant rhythm. All perifused pituitaries exhibited LH release patterns that were composed of significantly long ultradian rhythms (approximately 16 and 8 h, p < 0.001). Continuous stimulation with gonadotropin-releasing hormone (GnRH) or estradiol did not alter the periods of the observed rhythms but affected other rhythm parameters. Gonadotropin-releasing hormone increased the mesor of the rhythm and estradiol increased the amplitude. The results indicate that pituitary gonadotropes are capable of producing rhythms of LH release for a long duration in vitro, in the absence of hypothalamic control. Both GnRH and estradiol affect different rhythm parameters but do not change the periods of these rhythms.

Israel E Ashkenazi, Department of Human Genetics, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
Primary culture of human thyrocytes in Transwell bicameral chamber: thyrotropin promotes polarization and epithelial barrier function
Authors: Nilsson Mikael , Husmark Johanna , Nilsson Bengt , Tisell Lars-Erik , Ericson Lars E
Published: December 2008

Nilsson M, Husmark J, Nilsson B, Tisell L-E, Ericson LE. Primary culture of human thyrocytes in Transwell bicameral chamber: thyrotropin promotes polarization and epithelial barrier function. Eur J Endocrinol 1996;135:469–80. ISSN 0804–4643

Epithelial properties of thyrocytes are difficult to maintain in conventional cell culture systems. We used bicameral chambers (Transwell™) in attempts to establish a functional epithelium of thyrocytes of human origin. Thyroid follicle segments were isolated by collagenase digestion of paradenomatous tissue obtained at surgery for follicular adenoma and of tissue from glands with Graves' disease. After careful separation from connective tissue and single cells by centrifugation, the follicles were plated at high density on the collagen-coated filter of the chambers and cultured in Eagle's essential medium (EMEM) containing 10% fetal calf serum (FCS) or Coon's modified Hams medium enriched with five or six factors (5H, 6H); the latter media contained 5% FCS without (5H) or with (6H) thyrotropin (TSH). The follicles were converted into a confluent cell layer, which had similar DNA content irrespective of type of medium, after 4–6 days. Cells grown in EMEM or 5H established a transepithelial electrical resistance (R) of 200–500Ω·cm2 and was impermeable to [3H]inulin, indicating the formation of epithelial junctions. Addition of 6H to confluent cells initially cultured in EMEM or 5H caused a further increase of R, maximally to 1500 Ω·cm2, along with a rise of the transepithelial potential difference; 6H promoted the monolayer formation of cells, increased the number of apical microvilli and reinforced the junctional distribution of actin, cadherin and ZO-1; 6H also enhanced the polarized secretion of [3H]leucine-labeled thyroglobulin into the apical medium. Cells from Graves' thyroid tissue established an epithelium on the filter with similar characteristics to that of normal thyrocytes; some platings contained in addition large numbers of HLA-DR positive cells with a dendritic shape. HLA-DR expression was generally absent in EMEM- or 5H-grown thyrocytes, but appeared in limited areas of the cell layer after 6H and was expressed by all epithelial cells after interferon-gamma stimulation for 48 h. We conclude that human thyrocytes form a tight and polarized epithelium when cultured on permeable filters. The polarized structure and function of the cells are positively regulated by TSH. The culture system may be useful in studies addressing the role of the epithelial phenotype (cell polarity and tight barrier) in normal thyroid function as well as in pathological processes in the thyroid, such as autoimmunity, cell transformation and tumor progression.

Mikael Nilsson, Institute of Anatomy and Cell Biology, Göteborg University, Medicinaregatan 3, S-413 90 Göteborg, Sweden
l-Arginine is unlikely to exert neuroendocrine effects in humans via the generation of nitric oxide
Authors: Korbonits Márta , Trainer Peter J , Fanciulli Giuseppe , Oliva Osvaldo , Pala Alessandra , Dettori Alessandra , Besser Michael , Delitala Giuseppe , Grossman Ashley B
Published: December 2008

Korbonits M, Trainer PJ, Fanciulli G, Oliva O, Pala A, Dettori A, Besser GM, Delitala G, Grossman AB. l-Arginine is unlikely to exert neuroendocrine effects in humans via the generation of nitric oxide. Eur J Endocrinol 1996;135:543–7. ISSN 0804–4643

There is now considerable evidence that nitric oxide is an important neuroregulatory agent, but there has been very little investigation of its possible role in neuroendocrine mechanisms in humans. We have investigated the effects of two nitric oxide precursors, l-arginine and molsidomine, under basal conditions on the pituitary hormones growth hormone (GH), prolactin, luteinizing hormone, folliclestimulating hormone, thyrotrophin, adrenocorticotrophin (ACTH) and vasopressin, and also on serum cortisol; we have also studied the effect of l-arginine on circulating prolactin, ACTH and cortisol in normal human subjects under hypoglycaemic stress. l-Arginine stimulated both GH and prolactin release under basal conditions but had no effect on the other hormones studied, while the nitric oxide donor molsidomine showed no effect on any hormone studied. l-Arginine potentiated the hypoglycaemia-stimulated release of ACTH but did not influence the rise in GH. The current studies suggest that the effects of l-arginine on the stimulation of GH and prolactin release are unlikely to be mediated via the generation of nitric oxide.

A Grossman, Department of Endocrinology, St Bartholomew's Hospital, West Smithfield, London EC1A 7BE, UK
Follow-up of bone mineral density in 27 cases of anorexia nervosa
Authors: Maugars Yves M , Berthelot Jean-Marie M , Forestier Romain , Mammar Nadia , Lalande Sylvia , Venisse Jean-Luc , Prost Alain M
Published: December 2008

Maugars YM, Berthelot J-MM, Forestier R, Mammar N, Lalande S, Venisse J-L, Prost AM. Follow-up of bone mineral density in 27 cases of anorexia nervosa. Eur J Endocrinol 1996;135:591–7. ISSN 0804–4643

Cortical and trabecular bone loss can lead to osteoporosis in chronic forms of anorexia nervosa (AN). As there is some debate about the reversibility of this condition, we performed a longitudinal follow-up study of 27 cases in which clinical, biological, X-ray and lumbar and femoral neck dual photon absorptiometry examinations were conducted every 6 months for up to 30 months. Three groups were distinguished: G1, untreated amenorrheic AN (N = 14, total follow-up 126 months); G2, effectively treated AN (N = 11, total follow-up 192 months), with two subgroups: fluoride (N = 5) and estrogen (N = 6); and G3, remitting AN with normalization of the gonadic function (N = 2, total follow-up 36 months). Results were adjusted for each patient to a 6-month variation. Semestrial variations in lumbar bone mineral density (BMD) were −2.1 ± 1.3%, +2.8 ± 1.5% and −0.3 ± 1.3% (mean ± sem), respectively for G1, G2 and G3; those for femoral neck BMD semestrial variations were −5.9 ± 2.1%, −3.8 ± 1.2% and −1.0 ± 0.6%. Femoral neck and lumbar BMD variations for G1 were mainly correlated positively with bone-forming markers (serum osteocalcin, alkaline phosphatase) and negatively with initial lumbar BMD. Estrogen alone increased lumbar BMD by +1.4 ± 2.3% every 6 months but did not stabilize femoral neck BMD (−3.5 ± 1.4%). Fluoride increased lumbar BMD by 4.8 ± 1.8%. Both lumbar and femoral neck BMD were stabilized in the remission group (−0.3 ± 1.3% and −1.0 ± 0.6%), despite half of the follow-up time with amenorrhea. In conclusion, untreated AN is associated with a marked trabecular and cortical bone loss (4–10% per year), which can lead to osteoporotic fractures. In prevention of bone loss, the efficacy of estrogen is difficult to investigate in AN, even with a well-controlled trial. Our study could provide argument that, when the observance of this preventive treatment is assessed, lumbar BMD can be stabilized in chronic forms of AN.

Yves Maugars, CHU de Nantes, Service de Rhumatologie, 44035 Nantes, Cédex 01, France
Spironolactone therapy in hypertrichosis
Authors: Darendeliler F , Baş F , Balaban S , Bundak R , Demirkol D , Saka N , Günöz H
Published: December 2008

Darendeliler F, Baş F, Balaban S, Bundak R, Demirkol D, Saka N, Günöz H. Spironolactone therapy in hypertrichosis. Eur J Endocrinol 1996;135:604–8. ISSN 0804–4643

Although regarded as a benign condition, simple hypertrichosis may be very disturbing to a child cosmetically. An abnormality in androgen metabolism has been implied in the etiology of simple hypertrichosis recently. This study was undertaken to investigate the effect of spironolactone therapy for its antiandrogenic property in 12 prepubertal girls with hypertrichosis with no underlying etiology. The girls, with a mean age of 6.9 (1.2) years, had normal height and bone age. Basal hormone levels and adrenocorticotropin stimulation test results were in the normal ranges. Pelvic and adrenal ultrasound did not reveal pathology. Total and medullary hair width were measured from hair taken from preauricular, anterior midthigh, distal and proximal forearm areas. Spironolactone was started at an oral dose of 25 and increased to 100 mg·m−2·day−1 twice daily for 1 year. Total hair width decreased significantly in the preauricular and anterior midthigh regions up to 6–9 months of treatment. Medullary hair width, which was affected by therapy to a greater extent, decreased significantly in all regions up to 6 months. Both total and medullary hair width showed a tendency to increase afterwards. No side effects were encountered. Spironolactone may be used in the treatment of simple hypertrichosis; however, more data are needed to clarify the efficacy and safety of anti-androgen therapy in hypertrichosis.

Feyza Darendeliler, Istanbul Tip Fakültesi, Çocuk Kliniǧi, Çapa 34390, Istanbul, Turkey
Serum leptin and weight reduction in female obesity
Authors: Geldszus R , Mayr B , Horn R , Geisthövel F , von zur Mühlen A , Brabant G
Published: December 2008

Geldszus R, Mayr B, Horn R, Geisthövel F, von zur Mühlen A, Brabant G. Serum leptin and weight reduction in female obesity. Eur J Endocrinol 1996;135:659–62. ISSN 0804–4643

Leptin, an adipocyte-derived hormone, induces a decrease in food intake and increases energy expenditure via hypothalamic interactions. In animal models obesity can be caused by leptin deficiency or by a dysfunction of the hypothalamic leptin receptor. Using a radioimmunoassay for the determination of leptin in human serum, we measured serum leptin levels in 227 otherwise healthy normal weight (N = 78; body mass index = 16.1–27.7 kg/m2) or obese women (N = 149; body mass index = 27.8–56.7 kg/m2). Fifty-three subjects were followed over a period of 12 weeks under weight reduction (800 kcal/day) and a subgroup of 33 for another 13 weeks after termination of the diet. Body mass index and serum leptin concentrations were measured longitudinally and compared to female controls not under diet. Under baseline conditions, log serum leptin levels were positively related to body mass index with a best fit using a non-linear regression (p < 0.001), indicating an attenuated increase in serum leptin levels with high body mass index. No subgroup with low serum leptin levels could be identified. Weight reduction induced a rapid decrease in serum leptin levels within the first 3 weeks to levels significantly lower than in body mass index-matched controls under normal diet (p < 0.001). This pattern was consistent after 6 and 12 weeks. Serum leptin levels increased again after the end of the diet but remained significantly lower than in the controls despite unrestricted calorie intake over 7 weeks. The rapid and persistent decrease in serum leptin to lower levels than expected from matched controls may explain the pertinent difficulties of obese subjects to cope with weight reduction.

G Brabant, Abt. Klinische Endokrinologie Medizinische Hochschule Hannover, Konstanty-Gutschowstr. 8, D-30623 Hannover, Germany
Free and total insulin-like growth factors and insulin-like growth factor binding proteins during 14 days of growth hormone administration in healthy adults
Authors: Skjæbæk Christian , Frystyk Jan , Møller Jens , Christiansen Jens Sandahl , Ørskov Hans
Published: December 2008

Skjærbæk C, Frystyk J, Møller J, Christiansen JS, Ørskov H. Free and total insulin-like growth factors and insulin-like growth factor binding proteins during 14 days of growth hormone administration in healthy adults. Eur J Endocrinol 1996;135:672–7. ISSN 0804–4643

The objective was to investigate the effect of growth hormone (GH) administration on circulating levels of free insulin-like growth factors (IGFs) in healthy adults. Eight healthy male subjects were given placebo and two doses of GH (3 and 61U/m2 per day) for 14 days in a double-blind crossover study. Fasting blood samples were obtained every second day. Free IGF-I and IGF-II were determined by ultrafiltration of serum. Total IGF-I and IGF-II were measured after acid–ethanol extraction. In addition, GH, insulin, IGF binding protein 1 (IGFBP-1) and IGFBP-3 were measured. Serum-free and total IGF-I increased in a dose-dependent manner during the 14 days of GH administration. After 14 days, serum-free IGF-I values were 610 ± 100 ng/l (mean±sem) (placebo), 2760 ± 190 ng/l (3IU/m2) and 3720 ± 240 ng/l(6 IU/m2) (p = 0.0001 for 3 and 6 IU/m2 vs placebo; p = 0.004 for 3 IU/m2 vs 6 IU/m2). Total IGF-I values were 190 ± 10 μg/l (placebo), 525 ± 10 (3 IU/m2), and 655 ± 40 μg/l (6 IU/m2) (p < 0.0001 for 3 and 6IU/m2 vs placebo; p = 0.04 for 3 IU/m2 vs 6 IU/m2). There were no differences in the levels of free or total IGF-II during the three study periods. Insulin-like growth factor binding protein 1 was decreased during GH administration (p = 0.04 for placebo vs 3IU/m2; p = 0.006 for placebo vs 6 IU/m2). In conclusion, fasting serum free IGF-I increased dose dependently during GH administration and free IGF-I increased relatively more than total IGF-I. This may partly be due to the decrease in IGFBP-1.

Christian Skjærbæk, Institute of Experimental Clinical Research, Medical Research Laboratories, Aarhus Kommune Hospital, Norrebrogade 44, DK-8000 Aarhus C, Denmark
High plasma levels of endothelin-1 in untreated Addison's disease
Authors: Letizia Claudio , Centanni Marco , Scuro Luigi , Canettieri Gianluca , Cerci Sabrina , De Ciocchis Anita , D'Ambrosio Cecilia , Scavo Domenico
Published: December 2008

Letizia C, Centanni M, Scuro L, Canettieri G, Cerci S, De Ciocchis A, D'Ambrosio C, Scavo D. High plasma levels of endothelin 1 in untreated Addison's disease. Eur J Endocrinol 1996;135:696–9. ISSN 0804–4643

The aim of this study has been to investigate the plasma endothelin-1 (ET-1) levels in adult patients with proven Addison's disease (AD). Plasma ET-1 levels were measured in 29 subjects (17 males and 12 females, aged between 20 and 54 years): 15 of them were patients with AD and 14 were sex- and age-matched normal subjects, used as a control group. All patients with AD have been studied under basal conditions and nine of them also after 2 weeks on oral corticosteroid therapy (individual cortisol dosage ranging from 25 to 37.5 mg/day and 0.1 mg/day 9α-fluorohydrocortisone). Extracted plasma ET-1 was determined by a specific radioimmunoassay using rabbit endothelin antisera. Mean ET-1 values in the patients with AD were three times higher than in normal subjects (21.09 ± 4.38 pg/ml vs 6.72 ± 1.74 pg/ml; p < 0.0001). Plasma ET-1 levels assayed in the patients with AD after 2 weeks of corticosteroid therapy were significantly decreased (14.47 ± 3.7 pg/ml vs 22.8 ± 5.2 pg/ml; −37%; p < 0.001) compared to values in untreated patients. However, the plasma ET-1 values obtained following corticosteroid therapy were still significantly higher (p < 0.001) than those detected in the control subjects. These results clearly indicate that patients with untreated AD have increased circulating ET-1 levels that may be reduced by short-term corticosteroid therapy.

Claudio Letizia, Policlinico Umberto I, II Clinica Medica, 00185 Roma, Italy
Effects of UK-14,304, noradrenaline, and propranolol on insulin release from transplanted mouse islets
Authors: Shi Chun-Liang , Sehlin Janove , Täljedal Inge-Bert
Published: December 2008

Shi C-L, Sehlin J, Täljedal, I-B. Effects of UK-14,304, noradrenaline, and propranolol on insulin release from transplanted mouse islets. Eur J Endocrinol 1996;135:724–8. ISSN 0804-4643

To elucidate the adrenergic responsiveness of transplanted pancreatic islets, normal BALB/c mice received 150 syngeneic islets under the left kidney capsule. After 12–40 weeks, the grafts were removed and compared with untransplanted islets by an in vitro perifusion technique. Noradrenaline (NA), 3 μmol/l, completely inhibited glucose-stimulated insulin release from untransplanted islets but not from grafts, whether or not the β adrenergic blocker, L-propranolol, was present. UK-14,304, an α2-specific adrenergic agonist, inhibited glucose-induced insulin secretion from untransplanted islets by 80–92% at 0.1 or 1 μmol/l, and by 35–56% at 5–10 nmol/l, Insulin secretion from islet grafts was also markedly inhibited by 0.1 or 1 μmol/l, but not by 5 or 10 nmol/l, UK-14,304. It is suggested that the diminished adrenergic inhibition of insulin release from islet grafts reflects an altered function of the α2 adrenoceptors on the β-cells.

Chun-Liang Shi, Department of Histology and Cell Biology, Umeå University, S-901 87 Umeå, Sweden
Proinflammatory cytokines interleukin 1β and tumor necrosis factor α inhibit growth hormone stimulation of insulin-like growth factor I synthesis and growth hormone receptor mRNA levels in cultured rat liver cells
Authors: Wolf Matthias , Böhm Sebastian , Brand Marcus , Kreymann Georg
Published: December 2008

Wolf M, Böhm S, Brand M, Kreymann G. Proinflammatory cytokines interleukin 1β and tumor necrosis factor α inhibit growth hormone stimulation of insulin-like growth factor I synthesis and growth hormone receptor mRNA levels in cultured rat liver cells. Eur J Endocrinol 1996;135:729–37. ISSN 0804–4643

Low levels of insulin-like growth factor I (IGF-I) in critical illness are observed despite increased or normal levels of growth hormone (GH). The mechanisms for this apparent GH resistance have not been elucidated. As many of the acute inflammatory responses in critical illness are mediated by the proinflammatory cytokines interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α), the present studies evaluated IL-1β and TNF-α effects on steady-state and GH-stimulated IGF-I synthesis and GH receptor mRNA levels. In rat hepatocytes in primary culture, IGF-I released into culture medium was determined by radioimmunoassay, and quantitative competitive polymerase chain reaction was used to measure IGF-I mRNA and GH receptor mRNA concentrations. Growth hormone increased GH receptor mRNA, IGF-I mRNA and IGF-I protein secreted into the culture medium. In cells not stimulated with GH, modest inhibitory effects of IL-1β on GH receptor mRNA, IGF-I mRNA and IGF-I protein levels were seen. However, the stimulatory effects of GH were inhibited in a dose-dependent manner both by IL-1β and TNF-α, and at higher cytokine concentrations no stimulatory effects of GH were observed. Both IL-1β and TNF-α in submaximal dose had additive inhibitory effects on IGF-I protein concentrations but these effects did not result in irreversible damage to cells, as indicated by restoration of IGF-I and GH receptor mRNA levels to normal after withdrawal of cytokines. In conclusion, we demonstrated that in rat hepatocytes in primary culture IL-1β and TNF-α inhibited GH-stimulated IGF-I synthesis. Diminished GH receptor mRNA concentrations in response to IL-1β and TNF-α indicate that low IGF-I levels during severe illness, despite high circulating GH levels, may at least partially be a consequence of suppression of hepatic GH receptor synthesis by IL-1β and TNF-α.

Matthias Wolf, Medizinische Kern- und Poliklinik, Universitäts-Krankenhaus Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
Effect of vitamin D treatment in hypoparathyroid patients: a study on calcium, phosphate and magnesium homeostasis
Authors: Mortensen Lene , Hyldstrup Lars , Charles Peder
Published: December 2008

Aim: This study was undertaken to examine the effects of long-term vitamin D treatment on calcium, phosphate and magnesium homeostasis at organ level in hypoparathyroid patients.

Methods: Fifteen vitamin D-treated hypoparathyroid patients were studied, eight of the patients in a combined 47Ca kinetic and calcium, phosphate and magnesium balance study. Results were compared with a matched control group of 12 normal individuals.

Results: All the patients had normal serum levels of calcium, phosphate and magnesium. Absolute intestinal calcium absorption was increased (P <00001). Urinary calcium excretion was normal, but active tubular calcium reabsorption (TmCa/glomerular filtration rate) was low (P<0·001). Bone resorption rates and bone mineralization rates were very low (P <0001 and P <0·05). Twenty-four-hour urinary hydroxyproline excretion and serum cross-linked carboxyterminal telopeptide of type I were in the upper normal range. Serum alkaline phosphatase was normal, but serum carboxyterminal propeptide of human type I procollagen and serum osteocalcin were significantly reduced (P <0·05). Calcium balance was positive and significantly different from controls (P <0·001). All parameters from phosphate homeostasis were normal. Intestinal magnesium absorption was low though not significantly different from normal (P = 0·06). Urinary excretion of magnesium was not significantly higher than normal, but renal magnesium reabsorption was reduced (P <0·001). Magnesium balance was low, though the difference was not significant (P <0·06).

Conclusion: Long-term vitamin D treatment in hypoparathyroid patients resulted in a positive calcium balance. Bone turnover was very low. Results of bone markers and resorption rate were conflicting. Vitamin D treatment apparently normalized the abnormalities previously found in phosphate homeostasis of hypoparathyroid patients. Magnesium homeostasis was disturbed, with a more negative balance compared with normal subjects, implying a state of magnesium deficiency in these patients.

European Journal of Endocrinology 136 52–60
Lipoprotein(a) increase associated with thyroid autoimmunity
Authors: Lotz Helga , Salabè Giovanni B
Published: December 2008

Conflicting results have been reported regarding serum lipoprotein(a) (Lp(a)) concentrations in patients with hypothyroidism. We addressed the question whether thyroid autoimmunity could be associated with elevated Lp(a) values independent of the thyroid status. Lp(a) was measured by ELISA in 30 males, 29 premenopausal and 30 postmenopausal females positive for thyroid peroxidase- and/or thyroglobulin-antibody (T-Abs) and normolipidemic, screened out respectively from 428 male donors, 162 premenopausal donors and 108 postmenopausal females; they were compared with 65 males, 72 premenopausal and 48 postmenopausal females, negative for thyroid antibodies, normolipidemic and matched for age. T-Abs-positive male donors showed serum Lp(a) concentrations significantly increased compared with males without T-Abs (mean 19·7 ± 15·9 vs 12·7 ± 17·5 mg/dl; median 17·0 vs 4·0 mg/dl; Mann Whitney U test: P = 0·0000). In premenopausal females no difference could be found between T-Abs-positive and T-Abs-negative subjects (mean 13·2 ± 16·1 vs 12·3 ± 13·9 mg/dl; median 5·2 vs 8·7 mg/dl), suggesting an Lp(a) lowering effect of estrogens. The study was, therefore, extended to postmenopausal females. Significantly elevated Lp(a) levels were found in 30 postmenopausal females with T-Abs when compared with 48 postmenopausal females without T-Abs (40·0 ± 34·2 mg/dl vs 20·7 ± 19·3 mg/dl; median 32·0 vs 18·0 mg/dl; Mann Whitney U test: P = 0·0002). Finally, 21 postmenopausal, normolipidemic, autoimmune hypothyroid patients on l-thyroxine and euthyroid compared with 48 postmenopausal females without T-Abs also showed increased serum levels of Lp(a) (mean 27·0 ± 16·8 mg/dl vs 20·7 ± 19·3 mg/dl, median 25·0 vs 18 mg/dl; Mann Whitney U test: P = 0·0024). Thyrotropin levels in all subjects and patients were within the normal range. In conclusion, our results in males and postmenopausal females with T-Abs and euthyroid show an association between thyroid autoimmunity and increased levels of Lp(a), while the results obtained in premenopausal females suggest that estrogens might interfere with the Lp(a) increase related to thyroid autoimmunity.

European Journal of Endocrinology 136 87–91
Biologically active human islet amyloid polypeptide/amylin in transgenic mice
Authors: van Hulst Karen L , Born Walter , Muff Roman , Oosterwijk Cor , Blankenstein Marinus A , Lips Cornelis JM , Fischer Jan A , Höppener Jo WM
Published: December 2008

Objective: Human islet amyloid polypeptide (hIAPP), also named amylin, is a pancreatic β cell protein implicated in the pathogenesis of pancreatic islet amyloid formation and type 2 diabetes mellitus. To study the (patho)physiological roles of hIAPP, we have generated transgenic mice that overexpress hIAPP mRNA, in relation to endogenous mouse IAPP (mIAPP) mRNA, in pancreatic β cells. The biological activity of human and mouse IAPP derived from pancreatic extracts was determined.

Methods: Pancreatic and plasma extracts of transgenic and control mice were analyzed by reversedphase high-performance liquid chromatography (HPLC) and radioimmunoassay, yielding a separation of hIAPP from mIAPP. Biological activity of immunoreactive human and mouse IAPP components derived from pancreatic extracts was assessed by calcitonin receptor-mediated stimulation of cyclic AMP accumulation in T47D human breast carcinoma cells.

Results: The predominant immunoreactive human and mouse IAPP gene products had the retention times on HPLC analysis of the corresponding synthetic peptides. The ratio of bioactive over immunoreactive hIAPP and mIAPP was 0·93 ±0·18 and 1·19 ±0·56 respectively. In extracts of two plasma pools from 4 transgenic animals, hIAPP was 4·6- to 7-fold more abundant than mIAPP.

Conclusion; This study has shown that correctly processed hIAPP produced in transgenic mouse pancreatic β cells exhibits full biological activity. The results validate these transgenic mice for the study of (patho)physiological roles of hIAPP in vivo.

European Journal of Endocrinology 136 107–113
Abnormal carotid arterial wall dynamics in symptom-free hypopituitary adults
Authors: Markussis Viron , Beshyah Salem A , Fisher Charles , Parker Kim H , Nicolaides Andrew N , Johnston Desmond G
Published: December 2008

Objective: Although vascular mortality is increased in hypopituitary adults on routine replacement, there are limited data on the atherosclerotic process during life in these patients. Measurement of arterial stiffness may provide an index of early vascular changes that predispose to the development of major vascular accidents.

Design: Thirty-four hypopituitary adults on conventional replacement therapy and 39 age- and sex-matched controls were studied. They had no history or clinical evidence of macrovascular disease. The common carotid artery distensibility coefficient (DC), compliance coefficient (CC) and arterial stiffness index (beta index) were calculated from high-resolution ultrasonic imaging of the two common carotid arteries and from the brachial blood pressure.

Results: There was no difference between patients and controls in carotid diastolic diameter (mean ± s.e.m.) (5·55 ± 0·16 vs 5·45 ± 0·08 mm) and pulse pressure (6·66 ± 0·30 vs 6·58 ± 0·24 kPa). The increase in diameter during systole was significantly lower in the hypopituitary patients (0·39 ± 0·02 vs 0·50 ±0·03 mm, P < 0·001). The DC was significantly lower in patients than in controls (24·2 ± 2·29 vs 30·1 ± 2·01 10−3kPa−1, P < 0·05). The carotid CC was also significantly lower in patients than in controls (5·7 ± 0·49 vs 7·0 ± 0·45 10−7m2kPa−1, P < 0·05). The beta index was higher in the patient group (8·4 ± 1·3 vs 5·9 ± 0·37, P < 0·05). When men and women were considered separately, the differences between patients and controls were statistically significant in women but not in men and were more marked in the older women subgroup.

Conclusions: Asymptomatic hypopituitary adults (especially women) on conventional replacement therapy have increased stiffness of the common carotid arteries. These findings provide additional evidence for a process leading to premature atherosclerosis in this group of patients.

European Journal of Endocrinology 136 157–164
Population-based reference values for IGF-I and IGF-binding protein-1: relations with metabolic and anthropometric variables
Authors: Nyström Fredrik H , Öhman Peter K , Ekman Bertil Å , Österlund Maria K , Karlberg Bengt E , Arnqvist Hans J
Published: December 2008

Population-based reference values for IGF-I and IGF-binding protein-1 (IGFBP-1) have been established. One hundred and one women and the same number of men, 20–70 years old, were randomly selected from the population registry in the community of Linköping. Participation rate was 67%. Venous blood was drawn in the fasting state. Serum IGF-I was measured by RIA after acid-ethanol extraction and IGFBP-1 was determined by ELISA. IGF-I levels did not differ between genders and the decline with age was similar in men and women (men: Y=366–3·28×age (years), r =−0·61, P<0·0001; women: Y=386–3·49×age, r =−0·57, P<0·0001, P=0·4 for difference in slope). There were negative correlations between IGF-I and plasma lipids and blood pressure in both genders, but none was independent of age. Serum angiotensin-converting enzyme activity correlated positively with IGF-I in men independently from age (r =0·21, P=0·01). The distribution of IGFBP-1 was positively skewed and it was higher in women than in men (5·9±4·8 μg/l and 4·0±3·3 μg/l respectively; Mann–Whitney, P=0·002). In men and in the women not taking oestrogen, IGFBP-1 correlated positively with age (Spearman rank correlation (Spearman): men: r=0·32, P=0·002; women: r=0·24, P=0·03). C-peptide correlated negatively (Spearman: men: r =−0·38, P=0·002; women: r =−0·49, P<0·000) and sex hormone binding globulin positively with IGFBP-1 (Spearman: men: r=0·50, P<0·0001; women: r =0·55, P<0·0001).

IGF-I declined with age while IGFBP-1, which is considered to modulate the free bioactive fraction of IGF-I, increased. This suggests that IGF-I activity might be even lower in elderly subjects than is accounted for by the low total IGF-I.

European Journal of Endocrinology 136 165–172
Increased circulating leptin concentrations in insulin-resistant first-degree relatives of patients with non-insulin-dependent diabetes mellitus: relationship to body composition and insulin sensitivity but not to family history of non-insulin-dependent diabetes mellitus
Authors: Nyholm Birgit , Fisker Sanne , Lund Sten , Møller Niels , Schmitz Ole
Published: December 2008

Objective: To explore a possible association between serum concentration of leptin, insulin sensitivity and non-insulin-dependent diabetes mellitus (NIDDM).

Design: Forty first-degree relatives of NIDDM patients and 35 control subjects matched for age, gender and body mass index underwent a hyperinsulinaemic (insulin infusion rate 0·6 mU/kg per min) euglycaemic clamp combined with indirect calorimetry. Serum leptin was measured in fasting blood samples obtained before the clamp.

Results: All subjects had a normal oral glucose tolerance test. Insulin-stimulated glucose uptake (M) was decreased in the relatives compared with the control subjects (4·58 ± 0·27 versus 606 ± 0·25 mg/kg per min, P < 0·001). Conversely, serum leptin was increased in the relatives (9·6·/÷ 1·1 versus 6·1·/÷ 1·2 ng/ml (geometric mean·/÷ antilog s.e.m.). P < 0·05). A positive correlation was observed between circulating levels of leptin and percentage body fat (P < 0·001) and inverse correlations were found between leptin, M (P < 0·01), maximal aerobic capacity (VO2 max) (P < 0·01), and energy expenditure (P ≤ 0·01) in both groups. In multiple linear regression analysis, percentage body fat, gender and M significantly determined the level of leptin (r2 = 0·71, P < 0·001) whereas family history of NIDDM and VO2 max did not.

Conclusion: Serum leptin is increased in insulin-resistant offspring of NIDDM patients. The association between leptin, anthropometric measures and insulin sensitivity is, however, comparable with that of a control group. The increased concentrations of serum leptin in the relatives appear to be associated with the insulin resistance, but not with a family history of NIDDM.

European Journal of Endocrinology 136 173–179
Thyroid volume and urinary iodine in European schoolchildren: standardization of values for assessment of iodine deficiency
Authors: Delange F , Benker G , Caron Ph , Eber O , Ott W , Peter F , Podoba J , Simescu M , Szybinsky Z , Vertongen F , Vitti P , Wiersinga W , Zamrazil V
Published: December 2008

Up to 1992, most European countries used to be moderately to severely iodine deficient. The present study aimed at evaluating possible changes in the status of iodine nutrition in 12 European countries during the past few years. Thyroid volume was measured by ultrasonography in 7599 schoolchildren aged 7–15 years in one to fifteen sites in The Netherlands, Belgium, Luxemburg, France, Germany, Austria, Italy, Poland, the Czech and Slovak Republics, Hungary and Romania. The concentrations of urinary iodine were measured in 5709 of them. A mobile unit (ThyroMobil van) equipped with a sonographic device and facilities for the collection of urine samples visited all sites in the 12 countries. All ultrasounds and all urinary iodine assays were performed by the same investigators. The status of iodine nutrition in schoolchildren has markedly improved in many European countries and is presently normal in The Netherlands, France and Slovakia. It remains unchanged in other countries such as Belgium. There is an inverse relationship between urinary iodine and thyroid volume in schoolchildren in Europe. Goiter occurs as soon as the urinary iodine is below a critical threshold of 10 μg/dl. Its prevalence is up to 10 to 40% in some remote European areas. This work produced updated recommendations for the normal volume of the thyroid measured by ultrasonography as a function of age, sex and body surface area in iodine-replete schoolchildren in Europe. This study proposes a method for a standardized evaluation of iodine nutrition on a continental basis, which could be used in other continents.

European Journal of Endocrinology 136 180–187
Non-classical 21-hydroxylase deficiency in infancy and childhood: the effect of time of initiation of therapy on puberty and final height
Authors: Weintrob Naomi , Dickerman Zvi , Sprecher Elliot , Galatzer Avinoam , Pertzelan Atalia
Published: December 2008

Objective: To review the characteristics of children with non-classical 21-hydroxylase deficiency (NC-21-OHD) diagnosed during infancy and childhood, and to evaluate the relationship of pubertal and bone age maturation at initiation of glucocorticoid therapy with the course of puberty and final height.

Design: We retrospectively compared the course of puberty, growth pattern and final height in two groups of patients: group A (two males, six females), hydrocortisone (HC) treatment 7·5–15 mg/m2 per 24 h, initiated ≥1 year before onset of true puberty and group B (seven females), treatment started with the first signs of true puberty present.

Participants: Thirteen girls and two boys with NC-21-OHD diagnosed at age range 0·5–10·6 years were followed-up for 9·0 ± 3·8 years (mean±s.d.). Therapy with HC was initiated because of signs of hyperandrogenism, accelerated growth and bone maturation, or true precocious puberty. The HC dose was adjusted according to linear growth and basal plasma androgen levels.

Results: Puberty and peak height velocity developed significantly earlier in the girls of group B: gonadarche at 7·9 ± 1·4 years and peak height velocity at 9·2 ± 1·4 years vs 10·2 ± 0·4 years (P = 0·002) and 11·5 ± 0·7 years (P = 0·006) in group A. Menarche, however, occurred only slightly earlier in group B (12·0 ± 1·1 vs 12·8 ±0·5 years, P = 0·068). All eight children in group A achieved a final height within the range of their mean parental height standard deviation scores (SDS) in comparison with only 1/7 in group B (P = 0·0014). Seven of eight patients who started therapy before a bone age of 9 years achieved a final height within the parental height SDS range, compared with 2/7 who started therapy later (P = 0·041). The final height SDS was significantly better for group A (0·05 ± 0·19, mean ± s.e.m.) than group B (−1·63 ± 0·23, P = 0·0007), even when adjusted for a significant effect of the mean parental height SDS (A, −0·63 ± 0·28; B, −0·89 ± 0·31, P = 0·0245, ANCOVA).

Conclusion: Every child with signs of excess androgen activity or early puberty should be studied for the possibility of NC-21-OHD. Screening programs for populations with a high frequency of the gene for NC-21-OHD would facilitate early diagnosis and treatment. Pubertal stage and bone age at the introduction of therapy dictate height prognosis. Initiation of therapy before puberty with careful follow-up and HC dose adjustment can assure the achievement of genetic adult height.

European Journal of Endocrinology 136 188–195