bluuebunny/crossref_metadata_2025 huggingface dataset:
Involvement of protein kinase C in the stimulation of sodium-dependent phosphate transport by parathyroid hormone in osteoblast-like cells
Authors: Arao Makoto , Yamaguchi Toru , Sugimoto Toshitsugu , Fukase Masaaki , Chihara Kazuo
Published: December 2008

Arao M, Yamaguchi T, Sugimoto T, Fukase M, Chihara K. Involvement of protein kinase C in sodiumdependent phosphate transport by parathyroid hormone in osteoblast-like cells. Eur J Endocrinol 1994;131:646–51. ISSN 0804–4643

The rat osteosarcoma cell line UMR-106 has an osteoblast-like phenotype and possesses parathyroid hormone (PTH)-responsive dual signal transduction systems [adenosine 3′,5′-cyclic monophosphatedependent protein kinase (PKA) and calcium-protein kinase C (Ca-PKC)]. These cells transport inorganic phosphate (Pi) by a Na+-dependent carrier under stimulation by PTH. The present study aimed to clarify PTH-responsive signal transduction mechanisms in the regulation of Na+-dependent Pi transport by PTH in UMR-106 cells. Exposure of these cells to 10−7 mol/l PTH induced a significant increase in Pi uptake within 30 min of incubation and it became maximal after 2 h. Parathyroid hormone (10−9 –10−7 mol/l) stimulated Pi uptake dose dependently. Activation of PKC by 12-O-tetradecanoyl phorbol- 13-acetate (TPA) also increased Pi uptake in time- and dose-dependent manners similar to PTH In contrast, neither PKA activation by 10 mol/l forskolin or by 10−4 mol/l dibutyryladenosine 3′,5′-cyclic monophosphate nor calcium ionophore treatment with 10−7 mol/l A23187 or with 10−7 mol/l ionomycin during 3-h incubations affect Pi uptake, except its increase by 10−4 mol/l forskolin at a 3-h incubation. These agents had no influence on Pi uptake even in combined treatments with TPA. The PTH-induced increase in Pi uptake was abolished almost completely by pretreating cells with PKC inhibitors, 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine dihydrochloride (H-7) (50 μmol/l) or staurosporin (10 and 50 nmol/l), and by down-regulating PKC with a prolonged TPA treatment. These results indicate that the messenger system mediated by PKC, rather than by PKA or by cytosolic calcium, plays a crucial role in the regulation of Na+-dependent Pi transport by PTH within a few hours of exposure of the hormone in the osteoblast-like cells.

Toru Yamaguchi, Third Division, Department of Medicine, Kobe University School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650, Japan
Neuroendocrine regulation of growth hormone
Authors: Bertherat Jérôme , Bluet-Pajot Marie Thérèse , Epelbaum Jacques
Published: December 2008

Bertherat J, Bluet-Pajot MT, Epelbaum J. Neuroendocrine regulation of growth hormone. Eur J Endocrinol 1995;132:12–24. ISSN 0804–4643

This short review is focused on the neuroendocrine regulation of growth hormone (GH) pulsatile secretory pattern and GH gene expression. The neuronal network involved in the central control of GH includes extrahypothalamic neurons such as the noradrenergic and cholinergic systems, which regulate the two antagonistic neurohormonal systems: somatostatin (SRIH) and GH-releasing hormone (GHRH). Intrahypothalamic Proopiomelanocortin- and Galanin-containing interneurons also participate in the regulation of SRIH and GHRH neuronal activity, which also is dependent on sex steroids and GH and/or insulin-like growth factor I (IGF-I) feedback. cAMP (controlled mainly by GHRH and SRIH), thyroid and glucocorticoid hormones, IGF-I and activin are among the factors that regulate GH gene expression at the transcriptional level and may play a role in somatotroph differentiation and proliferation during ontogeny as well as physiological and pathological states such as acromegaly.

J Epelbaum, U159 INSERM, Centre Paul Broca, 2 ter rue d'Alésia, 75014 Paris, France
Quadriceps and hand-grip strength in adults with childhood-onset growth hormone deficiency
Authors: Sartorio Alessandro , Narici Marco , Conti Antonio , Monzani Marco , Faglia Giovanni
Published: December 2008

Sartorio A, Narici M, Conti A, Monzani M, Faglia G. Quadriceps and hand-grip strength in adults with childhood-onset growth hormone deficiency. Eur J Endocrinol 1995;132:37–41. ISSN 0804–4643

The effects of chronic growth hormone (GH) deficiency on muscle size and strength of postural (quadriceps) and non-postural (hand-grip) muscle groups, as well as on vertical jump capacity, were evaluated in six adults with childhood-onset GH deficiency. Data obtained were compared to those recorded in an age-, sex- and exercise-matched healthy control group. Thigh muscle plus bone cross-sectional area (CSAM+B) of the dominant quadriceps was significantly lower (p < 0.001) than in controls, while the CSAM+B/Body height)2 ratio was similar to that of controls. The maximum voluntary contraction (MVC) of the quadriceps of patients was significantly lower (p < 0.002) than in controls, while no differences existed in the quadriceps force expressed per unit area (MVC/CSA) between patients and controls. As far as hand-grip was concerned, the CSAM+B of the dominant forearm was significantly lower (p < 0.003) than in controls, while the CSAM+B/Body height)2 ratio was no different. The hand-grip MVC of patients was significantly lower (p < 0.004) than in controls, while no differences existed in the MVC/CSA ratio. It is noteworthy also that no difference existed in the hand-grip to quadriceps MVC ratio of the two groups. Furthermore, no differences were found in the vertical jump capacity, because both Δ Height and Δ Height/Body weight of patients were not significantly different from those of controls. In conclusion, our study suggests that GH deficiency seems to reduce the size and strength of postural and non-postural muscle groups to the same extent. However, these findings are likely to be attributed to a simple dimensional scaling, because their CSA/ (Body height)2, MVC/CSA and vertical jump capacity were comparable to those of controls.

Alessandro Sartorio, Laboratorio Sperimentale di Ricerche Endocrinologiche, Centro Auxologico Italiano, IRCCS, via Ariosto 13, 1-20145 Milan, Italy
Bone turnover and bone mineral density in young adult patients with panhypopituitarism before and after long-term growth hormone therapy
Authors: Balducci Rina , Toscano Vincenzo , Pasquino Anna M , Mangiantini Adele , Municchi Giovanna , Armenise Patrizia , Terracina Sandra , Prossomariti Giancarlo , Boscherini Brunetto
Published: December 2008

Balducci R, Toscano V, Pasquino AM, Mangiantini A, Municchi G, Armenise P, Terracina S, Prossomariti G, Boscherini B. Bone turnover and bone mineral density in young adult partients with panhypopituitarism before and after long-term growth hormone therapy. Eur J Endocrinol 1995;132:42–6. ISSN 0804–4643

We examined the effects of biosynthetic growth hormone (GH) on biochemical indices of bone turnover and on bone mineral density in a group of GH-deficient adults. Thirteen patients (eight males and five females) aged 24 ± 5 years (range 16–35) were studied before and 12 and 24 months after GH treatment (0.1 IU, kg− day−1, 6 days a week). Serum levels of insulin-like growth factor I (IGF-I), calcitonin, parathyroid hormone, alkaline phosphatase, intact osteocalcin, fasting urinary hydroxyproline/creatinine ratio and bone mineral density (BMD), measured at the lumbar spine by dualphoton absorptiometry, were evaluated. After 12 months of treatment, IGF-I, alkaline phosphatase, osteocalcin and the fasting urinary hydroxyproline/creatinine ratio increased significantly. However, after 24 months of therapy, serum levels of osteocalcin decreased to pretreatment values while IGF-I, fasting urinary hydroxyproline/creatinine ratio and alkaline phosphatase remained elevated significantly. No changes were found in parathyroid hormone and calcitonin plasma levels or in BMD either after 12 or 24 months of treatment. These data demonstrate that GH, at the dosage that we used, activates bone turnover during 24 months of therapy in adults with panhypopituitarism, even if a downward trend for osteocalcin became apparent at 24 months. However, this activation in bone turnover was not accompanied by an increase in BMD. We can hypothesize that GH, at the relatively high dosage used, may stimulate osteoclastic activity to a greater extent than osteoblastic activity. It is probable that the dose of GH replacement therapy in adults plays a key role

R Balducci, Dipartimento di Sanita Pubblica, Universita "Tor Vergata", Via di Tor Vergata 38, 00173 Roma, Italy
Abnormal calcitonin basal levels and pentagastrin response in patients with chronic renal failure on maintenance hemodialysis
Authors: Niccoli Patricia , Brunet Philippe , Roubicek Christa , Roux François , Baudin Eric , Lejeune Pierre-Jean , Berland Yvon , Conte-Devolx Bernard
Published: December 2008

Niccoli P, Brunet P, Roubicek C, Roux F, Baudin E, Lejeune P-J, Berland Y, Conte-Devolx B. Abnormal calcitonin basal levels and pentagastrin response in patients with chronic renal failure on maintenance hemodialysis. Eur J Endocrinol 1995;132:75–81. ISSN 0804–4643

Hypercalcitoninemia has been reported in renal failure. Using a specific monomeric calcitonin (CT) immunoassay, we measured CT levels in 154 hemodialyzed patients. The relationship between CT and serum intact parathyroid hormone (PTH), gastrin, alkaline phosphatases, phosphate and calcium was studied. The pentagastrin test was performed in 26 patients exhibiting basal hypercalcitoninemia. Basal CT levels over 5.7 pmol/l (20 ng/l) were found in 25.3% of the patients and values higher than 26 pmol/l (90 ng/l) in 7.8%. Although CT is cleared by hemodialysis, post-dialysis CT levels either were unchanged or increased as compared with pre-dialysis values. This suggests that hypercalcitoninemia is not related to a decreased renal clearance, and that hemodialysis induces a specific regulatory pathway. None of the parameters studied were found to explain high CT levels. Of the patients with hypercalcitoninemia, 11.5% exhibited abnormal CT response to pentagastrin but no relationship between CT and phosphate, calcium and PTH levels was evidenced. Our findings confirm high CT monomer levels in renal failure. As there was no correlation with parameters classically involved in CT regulation, its physiological significance remains unclear. Abnormal CT response to pentagastrin raises the problem of its specificity as a tumoral marker with regard to medullary thyroid carcinoma.

B Conte-Devolx, Service d'Endocrinologie et Maladies Métaboliques, Hôpital de la Conception, 147 Bd Baille, Marseille 13385 cedex 05, France
Immunohistochemical localization of inhibin α- and βA-subunits in the ovary of immature female rats
Authors: Kobayashi Mitsuko , Yamoto Mareo , Minami Sawako , Imai Miyako , Nakano Ryosuke
Published: December 2008

Kobayashi M, Yamoto M, Minami S, Imai M, Nakano R. Immunohistochemical localization of inhibin α- and βA-subunits in the ovary of immature female rats. Eur J Endocrinol 1995;132:97–102. ISSN 0804–4643.

Immunohistochemical localization of inhibin α- and βA-subunits was examined in the ovaries of immature female rats. The granulosa cells in various sized ovarian follicles obtained from rats that were 10–24 days old exhibited positive staining for inhibin α- and βA-subunits. The relative intensities of immunostaining for α- and βA-subunits increased during follicular growth and maturation. Ova and internal thecal cells did not show any immunostaining for inhibin α- and/or βA-subunits. These results suggest that granulosa cells of immature rat ovaries may produce inhibin from the 10th day after birth, and that an increase in the number of mature ovarian follicles results in an increase in inhibin production in the immature rat ovary during prepubertal development.

Mitsuko Kobayashi, Department of Obstetrics and Gynaecology, Wakayama Medical College, 1 shichibancho, Wakayama 640, Japan
Pituitary–testicular axis in rats lacking testicular macrophages
Authors: Gaytan F , Bellido C , Aguilar E , van Rooijen N
Published: December 2008

Gaytan F, Bellido C, Aguilar E, van Rooijen N. Pituitary–testicular axis in rats lacking testicular macrophages. Eur J Endocrinol 1995;132:218–22. ISSN 0804–4643

Testicular macrophages were depleted selectively in adult rats by intratesticular injections of liposome-entrapped dichloromethylene diphosphonate (Cl2MDP-lp), whereas control animals received intratesticular injections of phosphate-buffered saline-containing liposomes or 0.9% NaCl. The absence of macrophages in Cl2MDP-lp-injected rats was confirmed histologically. Rats lacking testicular macrophages showed significantly increased (twofold on average) serum concentrations of luteinizing hormone at 5 and 10 days after treatment. Serum luteinizing hormone concentrations drop to control values at 15 days after treatment. Serum testosterone concentrations were increased significantly (twofold on average) at 5, 10 and 15 days after treatment. No significant changes were found for follicle-stimulating hormone serum concentrations, or for the weights of the testes and sex accessory organs. Testicular histology was unchanged, except for the absence of testicular macrophages in Cl2MDP-lp-treated animals. Rats treated with NaCl or Cl2MDP-lp were injected with 100 IU of human chorionic gonadotrophin and sacrificed 2 h later. Serum testosterone concentrations increased 8.6-and 3.5-fold in NaCl and Cl2MDP-lp-treated rats, respectively, in response to acute human chorionic gonadotrophin treatment. These results point out the relevance of testicular macrophages for the regulation of the pituitary–testicular axis.

F Gaytan, Department of Cell Biology, School of Medicine, 14071 Córdoba, Spain
β-Adrenergic receptors are involved in histamine-induced secretion of proopiomelanocortin-derived peptides and prolactin in rats
Authors: Kjær Andreas , Knigge Ulrich , Matzen Steen , Warberg Jørgen
Published: December 2008

Kjær A, Knigge U, Matzen S, Warberg J. β-Adrenergic receptors are involved in histamine-induced secretion of proopiomelanocortin-derived peptides and prolactin in rats. Eur J Endocrinol 1995;132: 223–8. ISSN 0804–4643

The neurotransmitter histamine (HA) is involved in central regulation of secretion of prolactin (PRL) and the proopiomelanocortin (POMC)-derived peptides adrenocorticotropin (ACTH), β-endorphin (β-END) and α-melanocyte-stimulating hormone (α-MSH). The effect of HA on POMC-derived peptides and PRL release is, at least in part, indirect and may involve activation of catecholaminergic systems. Therefore, we investigated the effect of β-adrenergic receptor blockade on HA or HA agonist-induced release of ACTH, β-END, α-MSH and PRL. Central administration of HA, the H1-receptor agonist 2-thiazolylethylamine (2-TEA) or the H2-receptor agonist 4-methylhistamine (4-MeHA) stimulated the secretion of ACTH, β-END, α-MSH and PRL. Pretreatment with the β-adrenergic antagonist propranolol inhibited secretion of the POMC peptides in response to HA, 2-TEA or 4-MeHA. Propranonol only inhibited the PRL response to HA or 2-TEA, but had no effect on the PRL response to 4-MeHA. Administration of the β-receptor agonist isoproterenol stimulated ACTH, β-END, α-MSH and PRL two to five-fold. This effect was totally blocked by pretreatment with propranolol. We conclude that HA-induced secretion of POMC-derived peptides from the anterior and intermediate lobe of the pituitary gland and of PRL from the anterior lobe is, at least in part, mediated via catecholamines. β-Adrenergic receptors are involved in the mediation of the POMC response to H1- as well as H2-receptor activation, whereas β-receptors are involved only in the mediation of the PRL response to H1-receptor activation.

Andreas Kjær, Department of Medical Physiology, Division of Endocrinology and Metabolism, The Panum Institute (Building 12.3), University of Copenhagen, Blegdamsvej 3c, DK-2200 Copenhagen N, Denmark
Analysis of retroorbital T cell antigen receptor variable region gene usage in patients with Graves' ophthalmopathy
Authors: Heufelder Armin E , Herterich Steffen , Ernst Gabriele , Bahn Rebecca S , Scriba Peter C
Published: December 2008

Heufelder AE, Herterich S, Ernst G, Bahn RS, Scriba PC. Analysis of retroorbital T cell antigen receptor variable region gene usage in patients with Graves' ophthalmopathy. Eur J Endocrinol 1995; 132: 266–77. ISSN 0804–4643

To date, it has remained unclear whether orbit-infiltrating T cells in patients with Graves' ophthalmopathy (GO) represent a primary immune response in which a limited number of T cell clones driving the disease are activated against specific antigens, or whether they participate in a non-specific inflammatory process. To characterize these T cells at the molecular level, we examined the T cell antigen receptor (TcR) V gene repertoire in situ in retroorbital tissue specimens obtained from patients with early and late stages of clinically severe GO and from patients with non-GO orbital conditions. Ribonucleic acid extracted from orbital tissue and peripheral blood lymphocytes (PBL) was reverse transcribed and amplified using the polymerase chain reaction and 22 Vα and 24 Vβ genespecific oligonucleotide primers. The resulting TcR Vα and Vβ transcripts were verified by Southern hybridization analysis using TcR C region-specific, digoxigenin-labeled oligonucleotide probes. Compared with matched PBL, the retroorbital TcR Vα and Vβ gene repertoire expressed was heterogeneous, but revealed marked restriction of V gene usage in samples derived from retroorbital connective tissue and extraocular muscle of all eight patients with severe GO of short duration studied. In contrast, greater diversity of the TcR Vβ gene repertoire and loss of TcR Vα gene restriction was noted in four patients with late GO undergoing reconstructive eye muscle surgery. Unrestricted TcR V gene usage was demonstrated in orbital tissue and PBL samples obtained from control subjects. These results suggest that retroorbital TcR V gene usage is variable but markedly restricted during the earlier stages of GO. With increasing disease duration, greater diversity of the TcR V gene repertoire appears to develop, and oligoclonality of the T cell response may be lost. Selection of patients with early stages of GO will be important when further dissecting TcR usage and antigen specificity of orbit-infiltrating T lymphocytes in GO.

Armin E Heufelder, Molecular Thyroid Research Unit, Lab 280, Medizinische Klinik, Klinikum Innenstadt, Ludwig-Maximilians-Universität, Ziemssenstraße 1, 80336 München, Germany
A case of 16-ene-synthetase deficiency in male pseudohermaphroditism due to combined 17α-hydroxylase/17,20-lyase deficiency
Authors: Oei S Guid , Derksen Jan , Weusten Jos JAM , Lentjes Eef GWM , Helmerhorst Frans M
Published: December 2008

Oei SG, Derksen J, Weusten JJAM, Lentjes EGWM, Helmerhorst FM. A case of 16-ene-synthetase deficiency in male pseudohermaphroditism due to combined 17α-hydroxylase/17,20-lyasedeficiency. Eur J Endocrinol 1995;132:281–5. ISSN 0804–4643

A 17-year-old phenotypic female with primary hypergonadotropic amenorrhea, absence of secondary sexual development, hypertension and 46 XY karyotype is presented. Hormonal analysis revealed very low levels of testosterone, dehydroepiandrosterone, androstenedione, estrogens, cortisol and high levels of ACTH, progesterone, deoxycorticosterone and corticosterone. Enzyme studies of the testicular tissue after bilateral gonadectomy showed absence of 17α-hydroxylase and 17,20-lyase activity as well as 16-ene-synthetase activity. This enzyme catalyzes the reaction from pregnenolone to 5,16-androstadien-3β-ol, a sex pheromone precursor. The other enzyme systems leading from pregnenolone to testosterone were intact. This is the first report of male pseudohermaphroditism in which the combination of 17α-hydroxylase, 17,20-lyase and 16-ene-synthetase deficiency is described, indicating that all these activities might be associated with the same protein.

FM Helmerhorst, Department of Obstetrics, Gynecology and Reproductive Medicine, University Hospital Leiden, PO Box 9600, 2300 RC Leiden, The Netherlands
Growth hormone-binding protein-related immunoreactivity in the serum of patients with acromegaly is regulated inversely by growth hormone concentration
Authors: Kratzsch Jürgen , Blum Werner F , Ventz Manfred , Selisko Thomas , Birkenmeyer Gerd , Keller Eberhard
Published: December 2008

Kratzsch J. Blum WF, Ventz M, Selisko T, Birkenmeyer G, Keller E. Growth hormone-binding proteinrelated immunoreactivity in the serum of patients with acromegaly is regulated inversely by growth hormone concentration. Eur J Endocrinol 1994;132:306–12. ISSN 0804–4643

In this report we describe a newly developed radioimmunoassay (RIA) for the determination of the high-affinity growth hormone-binding protein (GHBP) in human blood. Using this RIA for the measurement of GHBP in serum of 29 patients with acromegaly, decreased concentrations were found compared to the normal range, depending on the activity of the disease. Growth hormonebinding protein was correlated inversely to log GH (r = −0.7, p < 0.001). A weaker relationship was shown between the GHBP activity determined in a functional assay based on charcoal separation and log GH (r = −0.51, p< 0.01). While insulin-like growth factor I (IGF-I) and IGF binding protein 3 (IGFBP-3) were correlated directly to log GH (r = 0.77 and r = 0.66, p < 0.001), an inverse and weaker relationship was evident between GHBP measured by RIA and IGF-I or IGFBP-3 (r = −0.61 and r = −0.57,p < 0.01). In contrast, no correlation could be detected between data of the functional GHBP assay and IGF-I or IGFBP-3, These results suggest, that: (1) in patients with acromegaly the GH receptor density in tissue reflected by the GHBP serum levels seems to be down-regulated, depending on the increased GH level; (2) low GHBP concentrations indicate an active disease in acromegaly and may be of diagnostic interest; (3) presuming that the GH receptor density is related to GH sensitivity, the variation of GH sensitivity is less important for IGF-I and IGFBP-3 production than the circulating GH concentration, at least in the situation of acromegaly; (4) because endogenous GH does not interfere in that assay, the RIA provides a valuable tool for the investigation of regulations between GH, GHBP and the GH receptor, especially in patients with acromegaly. The GHBP levels may be used as a sensitive parameter of GH oversecretion and tissue sensitivity to this hormone.

Jürgen Kratzsch, Inst. Clin. Chem., University of Leipzig, Paul-List-Str. 13–15, D-04103 Leipzig, Germany
Interpretation of growth hormone provocative tests: comparison of cut-off values in four European laboratories
Authors: Andersson Anna-Maria , Ørskov Hans , Ranke Michael B , Shalet Steve , Skakkebæk Niels E
Published: December 2008

Andersson A-M, Ørskov H, Ranke MB, Shalet B, Skakkebæk NE. Interpretation of growth hormone provocative tests: comparison of cut-off values in four European laboratories. Eur J Endocrinol 1995;132:340–3. ISSN 0804–4643

To compare interpretations of growth hormone (GH) provocative tests in laboratories using six different GH immunoassays (one enzymeimmunometric assay (EIMA, assay 1), one immunoradiometric assay (IRMA, assay 5), one time-resolved fluorimmunometric assay (TRFIA, assay 3) and three radioimmunoassays (RIAs, assays 2, 4 and 6)), aliquots of peak samples from GH provocative tests were distributed between the four participating laboratories, quantified in the respective immunoassays and interpreted according to the cut-off values for provocative tests defined for each assay method. There was a high degree of relative correlation between the different assays, but absolute GH estimates differed. Assays 2, 4, 5 and 6 yielded almost identical GH levels. Assays 1 and 3 yielded serum GH levels approximately 39% and 70%, respectively, of those of assays 2, 4, 5 and 6. Although the absolute GH level measured in the various assay methods varied, there was good agreement between the interpretation of a given sample among the participating laboratories. This indicates that the differences in estimates of serum GH concentration by different immunoassay systems can be compensated for when cut-off values are defined for each method.

Anna-Maria Andersson, Dept. of Growth and Reproduction, University Hospital of Copenhagen, Ward GR5064, 9 Blegdamsvej, DK-2100 Copenhagen Ø, Denmark
Antibodies against restricted sequences in human c-ErbA hinge domain recognize differentially natural mammalian α- or β-type triiodothyronine receptors and interfere differently with hormone binding
Authors: Bismuth Janine , Lenoir Christelle , Teboul Michèle , Daadi Malika , Giorgilli Gianfranco , Bonne Jeannine , Macchia Enrico , Planells Richard , Torresani Janine
Published: December 2008

Bismuth J, Lenoir C, Teboul M, Daadi M, Giorgilli G, Bonne J, Macchia E, Planells R, Torresani J. Antibodies against restricted sequences in human c-ErbA hinge domain recognize differentially natural mammalian α- or β-type triiodothyronine receptors and interfere differently with hormone binding. Eur J Endocrinol 1995;132:347–56. ISSN 0804–4643

In our first report, rabbit antibodies directed to recombinant polypeptides of human α-type c-ErbA sequences recognized natural triiodothyronine (T3) receptors (TR) in adipocytes (mouse Ob 17 cell line) but not in liver (mouse, rat). Moreover, some of them, directed to the sequence 150–228, markedly interfered with hormone binding to adipocyte T3 receptors. We now raised antibodies against shorter synthetic peptides within this α-type 150–228 c-ErbA sequence, which encompasses part of the hinge (D) domain and N-terminus of the E domain (α-150–166 and α 172–191) and against a β-type c-ErbA sequence (β 204–220 aligned on α 150–166, and differing by eight amino acids). Our present antibodies, which bear the expected c-ErbA α- or β-type specificity, immunoprecipitated the TR in nuclear extracts, with a different pattern between tissues: exclusive precipitation by anti-c-ErbA α antibodies in Ob 17 adipocytes; large but non-exclusive precipitation by anti-cErbA β antibodies in rat or mouse liver, which also expresses some α-type TR. This pattern of discriminative immunoprecipitation, also obtained in parallel analysis using our previously described antibodies to other c-ErbA α or β sequences (anti-α 144–162, anti-α1 403–410 and anti-β 62–82), roughly verifies results of c-erbA mRNA expression in these tissues. Slight differences appeared in the extent of α-type TR recognition by antibodies directed to α 172–191, whether TR were liganded or not to T3 before antibody addition. This evokes a different conformation of this region after hormone binding. Most interestingly, these anti-α 172–191 antibodies lowered the Ka for T3 and extensively dissociated the adipocyte T3–TR complexes; they interfered poorly with the binding of T3 in liver nuclear extracts. This strongly supports the concept that internal sequences in c-ErbA α, more precisely in a restricted Cterminal part of the D domain, are necessary for efficient T3 binding, which also need the C-terminal part of domain E.

J. Torresani, INSERM U38, Biochimie Méducake, Faculté de Médecine, 27 Bd J Moulin, 13385 Marseille Cédex 5, France
Orchidectomy selectively increases follicle-stimulating hormone secretion in gonadotropin-releasing hormone antagonist-treated male rats
Authors: Tena-Sempere M , Pinilla L , Aguilar E
Published: December 2008

Tena-Sempere M, Pinilla L, Aguilar E. Orchidectomy selectively increases follicle-stimulating hormone secretion in gonadotropin-releasing hormone agonist-treated male rats. Eur J Endocrinol 1995;132: 357–62. ISSN 0804–4643

The pituitary component of the feedback mechanisms exerted by testicular factors on gonadotropin secretion was analyzed in adult male rats treated with a potent gonadotropin-releasing hormone (GnRH) antagonist. In order to discriminate between androgens and testicular peptides, groups of males were orchidectomized (to eliminate androgens and non-androgenic testicular factors) or injected with ethylene dimethane sulfonate (EDS), a selective toxin for Leydig cells (to eliminate selectively androgens) and treated for 15 days with vehicle or the GnRH antagonist Ac-d-pClPhe-d-pClPhe-d-TrpSer-Tyr-d-Arg-Leu-Arg-Pro-d-Ala-NH2CH3COOH (Org.30276, 5 mg/kg/72 hours). Serum concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured 7 and 14 days after the beginning of treatment. We found that: in males treated with GnRH antagonist, orchidectomy or EDS treatment did not induce any increase in LH secretion; and orchidectomy, but not EDS treatment, increased FSH secretion in GnRH-treated males. The present results show that negative feedback of testicular factors on LH secretion is mediated completely through changes in GnRH actions. In contrast, a part of the inhibitory action of the testis on FSH secretion is exerted directly at the pituitary level. It can be hypothesized that non-Leydig cell testicular factor(s) inputs at different levels of the hypothalamic–pituitary axis in controlling LH and FSH secretion.

Manuel Tena-Sempere, Department of Physiology, Faculty of Medicine, University of Córdoba, 14004 Córdoba, Spain
Differences in insulin secretion between the rat and mouse: role of cAMP
Authors: Ma Yan Hui , Wang Jian , Rodd Gail G , Bolaffi Janice L , Grodsky Gerold M
Published: December 2008

Ma YH, Wang J, Rodd GG, Bolaffi JL, Grodsky GM. Differences in insulin secretion between the rat and mouse: role of cAMP. Eur J Endocrinol 1995;132:370–6. ISSN 0804–4643

Although information regarding insulin secretion usually is considered equivalent when generated in the mouse or the rat, it is established that the kinetics of insulin secretion from mouse and rat pancreatic beta cells differ. The mechanisms underlining these differences are not understood. The in vitro perfused pancreas and isolated islets of the mouse or rat were employed in this study to investigate the role of cyclic adenosine monophosphate (cAMP), a major positive modulator of betacell function, as one differentiating signal for the uniquely different insulin release from the beta cells of these commonly used rodents. Glucose-stimulated first-phase insulin release from the perfused pancreas of the rat was higher than the mouse when calculated per gram of pancreas or as fractional secretion, but this phase was identical in the two species when results were adjusted for total body weight. Whether related to insulin content, pancreatic weight or body weight, the rat pancreas responded to glucose with a progressively increasing second-phase insulin release compared to the mouse pancreas, which secreted a flat second-phase of lesser magnitude. Isolated islets from rat and mouse were comparable in insulin content whereas the basal cAMP level of mouse islets was less than half that of the rat. At submaximal stimulation with glucose or glucose + IBMX or forskolin, mouse islets exhibited lower cAMP levels to a given stimulus than the rat. In rat islets cAMP levels increased to approximately 1000 fmol per islet, although insulin secretion maximized by 100–150 fmol. Insulin release at the same 100–150fmol cAMP per mouse islet was one-third that of the rat and secretion had not maximized in mouse islets at 800 fmol. Despite their similar insulin contents, mouse islets consistently secreted less insulin for a given level of cAMP per islet than the rat. The lower capacity of mouse islets to achieve comparable cAMP levels was not the result of increased catabolic rate because the "half-time" disappearance of islet cAMP after a stimulus was similar (~1 min) for both species. It is concluded that, compared to the mouse, beta cells of the rat pancreas elicit a more pronounced secondphase insulin secretion that is due, at least in part, to a greater production of, and sensitivity to, cAMP.

Gerold M Grodsky, Metabolic Research Unit, University of California, H5W 1157, Box 0540, 3rd and Parnassus Avenue, San Francisco, CA 94143, USA
Identification of the thyroid Na+/I− cotransporter as a potential autoantigen in thyroid autoimmune disease
Authors: Raspé E , Costagliola S , Ruf J , Mariotti S , Dumont JE , Ludgate M
Published: December 2008

Raspé E, Costagliola S, Ruf J, Mariotti S, Dumont JE, Ludgate M. Identification of the thyroid Na+/I− cotransporter as a potential autoantigen in thyroid autoimmune disease. Eur J Endocrinol 1995;132: 399–405. ISSN 0804–4643

The thyroid gland is the target of several autoimmune diseases. Specific thyroid proteins have been identified as autoantigens associated with these diseases (e.g. thyroperoxidase, thyroglobulin and the thyrotrophin (TSH) receptor). In this paper, we report that the serum of a patient suffering from Hashimoto's thyroiditis, autoimmune gastritis and rheumatoid arthritis was able to inhibit the chronic TSH-induced I− uptake of dog thyrocytes in culture, even at a 1:1000-fold dilution, without affecting their 86Rb+ uptake. This blocking activity is rare as 147 sera (from patients positive for antibodies to the thyroid microsomes and the gastric parietal cell antigen, patients with Sjögren's syndrome, patients with a high titre of microsomal antibodies and low or negative for antibodies to thyroperoxidase, and patients with a high titre of microsomal antibodies and frank hypothyroidism) were negative when tested for their ability to inhibit I− uptake. Subsequently we tested 20 murine monoclonal antibodies previously obtained by immunizing mice with a crude human thyroid membrane preparation, which were all negative when tested against thyroglobulin and thyroperoxidase. One of the monoclonal antibodies displayed a 50% inhibition of the chronic TSH-induced 125I− uptake of dog thyrocytes without affecting the 86Rb+ uptake of the cells. Immunoglobulins purified from the ascite fluid by affinity chromatography on a protein A cellulose column had the same characteristics. Taken together, the data suggest that thyroidal 125I− uptake can be inhibited by antibodies, that autoantibodies in the patient's serum are most probably responsible for the observed inhibition and therefore that the Na+/I− cotransporter is probably an autoantigen.

E Raspé, IRIBHN, School of Medicine, Free University of Brussels (ULB), 808 route de Lennik, 1070 Bruxelles, Belgium
Four years' treatment of resistant acromegaly with octreotide
Authors: Mcknight John A , McCance David R , Sheridan Brian , Atkinson A Brew
Published: December 2008

McKnight JA, McCance, DR, Sheridan B, Atkinson AB. Four years' treatment of resistant acromegaly with octreotide. Eur J Endocrinol 1995;132:429–32. ISSN 0804–4643

This study was designed to ascertain the long-term safety and efficacy profile of the somatostatin analogue octreotide as treatment of refractory acromegaly. Eight patients (aged 21–62 years) with persistent growth hormone (GH) elevation (duration 1–15 years) despite previous therapy were studied. Octreotide was given subcutaneously in increasing doses for the first year to a maximum of 500 μg three times daily. The dose then was reduced to 200 μg three times daily for the next 3 years. At annual assessments, 24-h GH profiles, insulin-like growth factor I (IGF-I) and a side-effect profile including gall-bladder ultrasound were studied. Oral glucose tolerance tests (75 g) were performed basally and after 6 months and 3 years of therapy. Haemoglobin A1 (HbA1) was also assessed. Side effects were recorded. Mean GH (± sem) was 36.0 ± 9 mU/l basally and was reduced significantly at all subsequent assessments on therapy (4-year mean, 9.4 ± 2.1 mU/l). The IGF-I level also remained suppressed and was normalized in four of eight patients who remained on octreotide. Fasting plasma glucose and HbA1 were not changed by therapy but 2-h glucose was elevated after 6 months and 3 years (basal mean, 7.6 mmol/l (5.3–9.0 mmol/l); 3-year mean, 10.7 mmol/l (8.4–15.7 mmol/l); p < 0.05). Five patients developed gallstones and in three these had disappeared following 1 year of bile salt dissolution therapy. Octreotide continues to suppress serum GH and IGF-I long term without attenuation of effect. Gallstone formation is a major side effect. Two hours after glucose load the plasma glucose level was elevated but HbA1 did not change long term. Further similar studies of long duration are required to establish the long-term safety profile of the drug.

AB Atkinson, Sir George E Clark Metabolic Unit, Royal Victoria Hospital, Belfast BT12 6BA, Northern Ireland
Quantification of urinary insulin-like growth factors (IGFs) and IGF binding protein 3 in healthy volunteers before and after stimulation with recombinant human growth hormone
Authors: Tönshoff Burkhard , Blum Werner F , Vickers Mark , Kurilenko Sabine , Mehls Otto , Ritz Eberhard
Published: December 2008

Tönshoff B, Blum WF, Vickers M, Kurilenko S, Mehls 0, Ritz E. Quantification of urinary insulin-like growth factors (IGFs) and IGF binding protein 3 in healthy volunteers before and after stimulation with recombinant human growth hormone. Eur J Endocrinol 1995;132:433–7. ISSN 0804–4643

We examined excretion of urinary insulin-like growth factors I and II (IGF-I and IGF-II) and their major binding protein IGFBP-3 in comparison to their respective serum concentration in nine healthy female volunteers (median age 25 years, range 22–27) under baseline conditions and after stimulation with recombinant human growth hormone (rhGH), 4.5 IU twice daily subcutaneously for a period of 3 days. The IGFs were measured in unconcentrated urine by use of recently developed, highly sensitive radioimmunoassays. The IGFBP-3 was measured by a specific radioimmunoassay. The mean (±sd) urinary concentrations of IGF-I (0.08 ± 0.07 μg/l), IGF-II (1.02 ± 0.47 μg/l) and IGFBP-3 (19.1 ± 6.9 μg/l) were two to three orders of magnitude lower than in serum. The ratio of IGF-II over IGF-I concentration in urine (13:1) was five times higher than in serum (2.5:1), and the ratio of IGFBP-3 over the sum of IGF-I and IGF-II in urine (17:1) was four times higher than in serum (4:1). Urinary excretion was 63.3 ± 46.6 ng·m−2 · 24 h−1 for IGF-I, 1002 ± 598 ng·m−2 · 24 h−1 for IGFII and 18039 ± 4983 ng·m−2·24 h−1 for IGFBP-3. Using fast protein liquid exclusion chromatography, only immunoreactive IGFBP-3 components of less than 60 kD were detected in urine, with a major peak at 20kD. Urinary IGFBP-3 excretion correlated with serum IGFBP-3 (r = 0.61, p < 0.01) and the glomerular filtration rate (r = 0.56, p < 0.05) measured by steady-state inulin infusion clearances. Administration of rhGH stimulated significantly (p < 0.005) the serum IGF-I concentration by 50%, but not the urinary IGF-I excretion. In conclusion: the considerably higher ratio of IGF-II to IGF-I in urine compared to serum indicates that urinary IGF excretion does not represent only filtered IGFs, urinary IGF-I is a less sensitive indicator of GH activity than serum IGF-I, and as urinary IGFBP-3 excretion is in proportion to the glomerular filtration rate and serum IGFBP-3, it presumably reflects renal filtration of small immunoreactive IGFBP-3 fragments from the circulation.

Burkhard Tönshoff, University Children's Hospital, Im Neuenheimer Feld 150, 69120 Heidelberg, Germany
Midmolecular parathyroid hormone-related peptide in serum during pregnancy, lactation and in umbilical cord blood
Authors: Bucht Elisabet , Rong Haiqin , Bremme Katarina , Granberg Barbro , Rian Edith , Tørring Ove
Published: December 2008

Bucht E, Rong H, Bremme K, Granberg B, Rian E, Tørring 0. Midmolecular parathyroid hormonerelated peptide in serum during pregnancy, lactation and in umbilical cord blood. Eur J Endocrinol 1993;132:438–43. ISSN 0804–4643

Indications of an important physiological role of parathyroid hormone-related peptide (PTHrP) for fetal calcium homeostasis, maternal–fetal calcium transport and reproduction have accumulated over recent years. The PTHrP concentrations were measured by an earlier developed midregion radioimmunoassay in serum from lactating healthy females and umbilical cord blood and compared with levels in age-matched non-pregnant or lactating females. The PTHrP concentrations could be measured in all samples after silica cartridge C18 extraction of 10–12 ml of serum. The concentrations were significantly higher during lactation (mean ± sd: 0.72 ± 0.14 pmol/l, N = 22) and in umbilical cord blood (0.85 ± 0.18 pmol/l, N =12) compared with healthy age-matched women (0.48 ± 0.09 pmol/l, N = 10, p< 0.001). The molecular forms of PTHrP were also studied in an agematched control group, in pregnant women and in umbilical cord blood by gel chromatography in a fast protein liquid chromatography system of Sep-Pak-extracted pooled serum. In all three groups we found heterogeneity of the molecular forms with two predominant peaks. The smallest fragment had a molecular weight of 4–6 kD while the largest form appeared as a high-molecular-weight molecule. In conclusion, the concentrations of midmolecule PTHrP fragments in serum are elevated during lactation and in umbilical cord blood. Because the midregion of PTHrP has unique actions, our results indicate that PTHrP may play an important physiological role for the mother and for the maternal–fetal calcium transport.

Elisabet Bucht, Department of Molecular Medicine, Unit of Endocrinology and Diabetology, Karolinska Hospital, S-171 76 Stockholm, Sweden
Inappropriately low levels of gonadotrophins in amenorrhoeic women with alcoholic and non-alcoholic cirrhosis
Authors: Bell Helge , Raknerud Nils , Falch Jan A , Haug Egil
Published: December 2008

Bell H, Raknerud N, Falch JA, Haug E. Inappropriately low levels of gonadotrophins in amenorrhoeic women with alcoholic and non-alcoholic cirrhosis. Eur J Endocrinol 1995;132:444–9. ISSN 0804–4643

We investigated a group of 111 amenorrhoeic females with associated liver disease. These comprised alcoholic cirrhotics (N = 38), non-alcoholic cirrhotics (N = 12), non-cirrhotic alcoholics (N = 21) and those suffering from other chronic liver diseases (N = 40) admitted to our medical department from 1986 to 1991. The serum levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), oestradiol, testosterone, sex hormone binding globulin (SHBG) and prolactin were measured. Serum LH was decreased below the normal range in 50% of patients with alcoholic cirrhosis and in 42% of patients with non-alcoholic cirrhosis. One third of non-cirrhotic alcoholics also had decreased LH, in contrast to only 8% of patients with other chronic liver diseases (p < 0.01). A close correlation was found between LH and FSH when all patients were pooled (r = 0.91, p < 0.001). A gonadotrophin-releasing hormone (GnRH) injection elicited a clear LH and FSH response in 11 out of 14 patients with cirrhosis, indicating that the hypothalamus rather than the pituitary is the site of disturbance in gonadotrophin secretion. Serum SHBG was within normal limits and similar in all four groups. In nine females with alcoholic cirrhosis who abstained for 3 months, serum SHBG increased significantly from 39 ± 18 to 70 ± 25 nmol/l (p < 0.001), while LH increased in five of nine females and was unchanged in four. In conclusion, half of the amenorrhoeic females with alcoholic as well as non-alcoholic cirrhosis had inappropriately low serum LH and FSH levels, indicating dysfunction of the hypothalamo–pituitary axis. The GnRH test indicated that disturbed hypothalamic function was the cause of the decreased LH and FSH secretion.

Helge Bell, Department of Medicine, Aker University Hospital, Trondhjemsveien 235, 0514 Oslo, Norway
Altered glycosylation of pituitary gonadotropins in anorexia nervosa: an alternative explanation for amenorrhea
Authors: Tommaselli Antonio P , Valentino Rossella , Savastano Silvia , Randazzo Giacomino , Scalfi Luca , Contaldo Franco , Dorato Maurizio , Lombardi Gaetano
Published: December 2008

Tommaselli AP, Valentino R, Savastano S, Randazzo G, Scalfi L, Contaldo F, Dorato M, Lombardi G. Altered glycosylation of pituitary gonadotropins in anorexia nervosa: an alternative explanation for amenorrhea. Eur J Endocrinol 1995;132:450–5. ISSN 0804–4643

To investigate the relevance of glycoprotein polymorphism to gonadotropin bioactivity in vivo, plasma follicle-stimulating hormone (FSH) and luteinizing hormone (LH), 17β-estradiol (E2), testosterone and sex hormone binding globulin (SHBG) levels in 17 amenorrheic women affected with anorexia nervosa (14–29 years) and 10 age-matched normally cycling women were evaluated. Plasma FSH and LH levels were assayed using radioimmunoassay (RIA) and immunoradiometric assay (IRMA) methods, before and after concanavalin A–Sepharose (Con A) affinity chromatography. Significant RIA–IRMA differences in FSH and LH plasma values were present only in women with anorexia nervosa (p < 0.005). Moreover, in these patients both FSH and LH showed a reduced binding to the Con A, expressed as a percentage of unbound, suggesting altered glycosylation of these moieties. In conclusion, these findings hypothesize the involvement of glycosylation polymorphism in RIA-IRMA differences; support the usefulness of both RIA and IRMA methods in FSH and LH evaluation, before and after Con A chromatography; and suggest a new pathogenetic pathway to explain amenorrhea in anorexia nervosa.

Antonio P Tommaselli, Chair of Endocrinology, University Federico II, via Pansini, 5, 80131-Naples, Italy
Water retention after oral chlorpropamide is associated with an increase in renal papillary arginine vasopressin receptors
Authors: Hensen J , Haenelt M , Gross P
Published: December 2008

Hensen J, Haenelt M, Gross P. Water retention after oral chlorpropamide is associated with an increase in renal papillary arginine vasopressin receptors. Eur J Endocrinol 1995;132:459–64. ISSN 0804–4643

Chlorpropamide (CP), a sulfonylurea used for treatment of non-insulin dependent diabetes mellitus, is known to potentiate the antidiuretic action of arginine vasopressin (AVP), predisposing to hyponatremia. It has been suggested that CP acts directly on the antidiuretic vasopressin receptor. Detailed studies on the influence of CP on the AVP receptor, however, have been hampered by lack of a suitable radioligand. Using a newly developed radioiodinated derivative of AVP with high specific activity and high affinity for the AVP V2-receptor (125I-[8-(p-(OH)-phenylpropionyl)]-LVP), we studied the role of AVP V2-receptors in CP-induced water retention. Male-Sprague-Dawley rats were treated orally with 40 mg CP/day or placebo for 7 days, after which Scatchard analysis was performed using membranes prepared from homogenized renal papilla. After oral water load, CP-treated rats but not control rats showed a significant decrease in plasma osmolality (289 ±2.2 to 284±0.8 mosmol/kg, p < 0.05). The Kd was 0.69 ± 0.16 nmol/l in controls and 0.70 ± 0.12 nmol/l after CP treatment (NS); Bmax was 129 ± 5.3 nmol/kg protein in controls (N = 8). Chlorpropamide significantly increased receptor density (Bmax) to 167±8.4 nmol/kg protein (N = 8) (p<0.05). Plasma AVP did not change significantly during CP treatment. These data show for the first time that CP in vivo increases the density of AVP V2 receptors without altering plasma AVP. This is associated with an impairment in water excretion. Our experiments and recent reports on CP-induced inhibition of AVP binding suggest that the AVP augmentation effect of CP is related to interference of CP with the AVP V2-receptor. Johannes Hensen, Department of Medicine I, Division of Endocrinology and Metabolism, Krankenhausstr. 12, 91054 Erlangen, Germany