bluuebunny/crossref_metadata_2025_split huggingface dataset:
Developmental changes and differential regulation by testosterone and estradiol of growth hormone receptor expression in the rabbit
Authors: Yu Yu M , Domené Horacio M , Sztein Jorge , Counts Debra R , Cassorla Fernando 
Published: December 2008

Yu YM, Domené HM, Sztein J, Counts DR, Cassorla F. Developmental changes and differential regulation by testosterone and estradiol of growth hormone receptor expression in the rabbit. Eur J Endocrinol 1996;135:583–90. ISSN 0804–4643
To investigate the effects of testosterone and estradiol (E2) on growth hormone receptor (GH-R) gene expression, we measured GH-R mRNA levels in relation to the changes of sex steroid concentrations in the normal male rabbits aged 1–12 months and after administration of testosterone or E2 to castrated male rabbits. In the normal animals, E2 levels were below the detection limit in all age groups, and testosterone levels were below the detection limit at 1 month, increased at 2 months and reached the plateau of the adult levels after 4 months. Liver GH-R mRNA levels were low at 1 month, reached a peak at 2 months and then decreased slightly thereafter. In the castrated animals, liver and growth plate GH-R mRNA levels were increased in the testosterone-treated group (162.0 ± 12.0%, p < 0.025; 128.4 ± 7.6%; p < 0.025) and reduced in the E2-treated group (29.6 ± 6.2%, p < 0.005; 53.6 ± 11.3%, p < 0.025). Sex steroid administration did not result in any significant change in GH-R mRNA levels in striated muscle, kidney and heart. Serum GH concentrations were increased in E2 (15.3 ± 7.7 μg/l vs 4.8 ± 2.2 μg/l, p < 0.025) but the increase was not significant in testosterone-treated animals (8.4 ± 7.7 μg/l vs 4.8 ± 2.2 μg/l). Both testosterone and E2 treatment resulted in a reduction of mean serum growth hormone-binding protein (GHBP) levels compared to control animals (1077 ± 422 pmol/l, p < 0.01; 1137 ± 443 pmol/l, p < 0.01; 2308 ± 565 pmol/l). We conclude that in addition to their stimulatory effect on GH secretion, testosterone and E2 have opposite effects on GH-R gene expression in liver and growth plate in the rabbit. The modulation of GH-R expression by sex steroids may be important for growth during sexual maturation in mammals.
Yu M Yu, MD, 11600 Bootjack Court, Gaithersburg, MD 20878, USA
Water distribution in insulin-dependent diabetes mellitus in various states of metabolic control
Authors: Brizzolara A , Barbieri MP , Adezati L , Viviani GL 
Published: December 2008

Brizzolara A, Barbieri MP, Adezati L, Viviani GL. Water distribution in insulin-dependent diabetes mellitus in various states of metabolic control. Eur J Endocrinol 1996;135:609–15. ISSN 0804–4643
Alterations in water compartments have been described in insulin-dependent diabetes mellitus (IDDM). Both insulin and lack of natriuretic counteracting response lead to water expansion, while hyperglycemica-induced osmotic diuresis leads to water depletion. Both total body water and water distribution in the extra-intracellular space, as well as their relationships to metabolic control, were investigated in 15 controls (30.1 ± 1.4 years) and in 26 IDDM patients (31.3 ± 1.6, diabetes duration 11.3 ± 1.4 years) who were neither hypertensive nor proteinuric. The amounts of total body water (TBW) and extracellular water (ECW) were predicted by impedance measurements at 100 KHz and at 1 KHz. The amount of intracellular water (ICW) was computed as the difference between the two. Water distribution was estimated by measuring the ratio between low- and high-frequency impedance and by computing the ratio between ECW and ICW. The IDDM patients were divided into four groups on the basis of reference HbA1c mean and sd: A ≤ mean +2 sd < B ≤ mean + 4 sd < C ≤ mean + 6sd < D. The groups were comparable with sodium intake, insulin dosage, fasting glycemia and laboratory hydration markers. As compared to controls, impedance values at 1, 5, 10, 50 and 100 KHz were significantly lower in diabetic patients and the difference within group D increased as the frequency increased: −3.9% at 1 KHz, −10.1% at 100 KHz. As compared to controls, groups A, B and C showed higher TBW, ECW and ICW while water distribution was normal, and group D showed higher TBW and ICW but normal ECW and a different water distribution. In all IDDM patients, HbA1c correlated with ECW (r = −0.49) and distribution ratios (r = 0.42, impedance; r = 0.40, ECW/ICW ratio). These observations suggest that good or moderate long-term control IDDM patients have proportionately normal distributions of ECW and ICW excess. However, water excess in poor control IDDM patients was only found in the ICW space.
Giorgio L Viviani, Department of Internal Medicine, Clinica Medica III, University of Genoa, Viale Benedetto XV, 6. 16132 Genoa, Italy
Regulation of obese mRNA expression by hormonal factors in primary cultures of rat adipocytes
Authors: Yoshida Tadashi , Hayashi Matsuhiko , Monkawa Toshiaki , Saruta Takao 
Published: December 2008

Yoshida T, Hayashi M, Monkawa T, Saruta T. Regulation of obese mRNA expression by hormonal factors in primary cultures of rat adipocytes. Eur J Endocrinol 1996;135:619–25. ISSN 0804–4643
The obese (ob) gene has been cloned recently and its protein product is called "leptin". Leptin is an adipocyte-derived satiety factor that regulates body weight homeostasis. Several hormonal factors have been reported to regulate ob mRNA expression. To determine which factors are most important for regulation of ob mRNA expression, we examined the effects of insulin, dexamethasone, a β3-adrenergic agonist (CGP12177A), 8-bromo-cAMP, 8-bromo-cGMP and 1-methyl-3-isobutylxanthine (MIX) on primary cultured adipocytes. Rat adipocytes obtained from epididymal fat were cultured using the ceiling method. Total RNA was extracted and the expression of ob mRNA was measured by quantitative reverse transcription-polymerase chain reaction. After 24 h of incubation, 100 nmol/l insulin significantly increased the expression of ob mRNA (21.4-fold compared to control). Moreover, insulin increased ob mRNA expression in a dose-dependent manner over a range of 1–100 nmol/l. The effect of 100 nmol/l insulin was similar to that seen with 20% newborn calf serum. Dexamethasone (25–1000 nmol/l) also increased ob mRNA expression (2.5–2.9-fold). The effect of dexamethasone occurred more rapidly than insulin. CGP12177A (1–10 μmol/l) and 0.5 mmol/l 8-bromo-cAMP had no effects, whereas 0.5 mmol/l 8-bromo-cGMP and 0.5 mmol/l MIX had stimulatory effects (2.8- and 2.4-fold increase in ob mRNA, respectively). The combination of 250 nmol/l dexamethasone and 0.5 mmol/l MIX did not have an additive effect on ob mRNA levels. Our present data suggest that, of these agents, insulin is the most important factor regulating ob mRNA expression.
Matsuhiko Hayashi, Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160, Japan
Effects of glucocorticoids and of growth hormone on serum leptin concentrations in man
Authors: Berneis Kaspar , Vosmeer Susanne , Keller Ulrich 
Published: December 2008

Berneis K, Vosmeer S, Keller U. Effects of glucocorticoids and of growth hormone on serum leptin concentrations in man. Eur J Endocrinol 1996;135:663–5. ISSN 0804–4643
Recent data suggest an involvement of the ob gene and its product leptin in the regulation of body fat. To assess the effects of glucocorticoids and growth hormone (GH) on serum leptin and body fat, 30 normal subjects received methylprednisolone (0.5 mg·kg−1·day−1) per os for 7days and 15 subjects received in addition sc injections of GH (0.15 IU·kg−1·day−1)−1) twice daily (combination group). Serum leptin levels increased both in the glucocorticoid group (p < 0.02) and in the combination group (p < 0.002). When body fat was estimated by bioelectrical impedance analysis it decreased during combined treatment and remained unchanged in the glucocorticoid group. Plasma insulin concentrations increased in both groups. Resting energy expenditure (indirect calorimetry) increased in the combination group and remained unchanged in the glucocorticoid group. The finding of increased serum leptin concentrations during treatment with glucocorticoid and GH suggests that serum leptin is regulated by glucocorticoids, possibly though changes in insulin secretion, independently of changes of body fat mass.
Ulrich Keller, Departments of Research and of Internal Medicine, University Hospital Basel, Petersgraben 4, 4031 Basel, Switzerland
Dose-dependent effects of recombinant human growth hormone on biochemical markers of bone and collagen metabolism in adult growth hormone deficiency
Authors: Bollerslev Jens , Møller Jens , Thomas Sian , Djøseland Ole , Christiansen Jens S 
Published: December 2008

Bollerslev J, Møller J, Thomas S, Djøseland O, Christiansen JS. Dose-dependent effects of recombinant human growth hormone on biochemical markers of bone and collagen metabolism in adult growth hormone deficiency. Eur J Endocrinol 1996:135:666–71. ISSN 0804–4643
Administration of growth hormone (GH) to patients with growth hormone deficiency (GHD) has beneficial effects, but so far has been employed only empirically. We have, therefore, investigated the dose-dependent effect of GH on target tissue by studying biochemical markers of bone and collagen turnover in GHD. Then patients with GHD (nine males and one female aged 21–43 years, mean age 28 years) participated in the study. Growth hormone deficiency was defined as a peak serum GH response of less than 15 mU/l in two provocation tests. After a 4-week run-in period, the study population received increasing doses of GH at 4-week intervals (1,2 and 4U/m2). Blood samples were collected in the fasting state at 7.00 h on the last day of each period and assayed for serum levels of osteocalcin (S-BGP), bone alkaline phosphatase (B-ALP), C-terminal propeptide of type I collagen (S-PICP), carboxy-terminal pyridinoline cross-linked telopeptide of type I collagen (S-ICTP) and N-terminal propeptide of type III collagen (S-PIIINP). Following replacement therapy, serum insulin-like growth factor I and insulin-like growth factor binding protein 3 increased sequentially with time (p<0.001 and p<0.001, MANOVA) and the values were elevated significantly over baseline levels after treatment with 1 U/m2. Serum BGP values were below normal at the start of the study and increased gradually following GH treatment to levels in the low–normal range. Baseline values for serum bone alkaline phosphatase (B-ALP), PICP and PIIINP were within the normal range. The collagen parameters increased with GH replacement (p<0.001, MANOVA) to levels above normal, whereas B-ALP stayed within normal limits. Serum ICTP values were elevated above the normal range at baseline, indicating increased bone resorption in GHD. A linear increase in values was observed with GH treatment (p< 0.001, MANOVA). Serum ICTP did not correlate significantly with the bone formative parameters but was correlated positively to PIIINP. The sensitivity of S-ICTP as a bone resorptive marker is thus questioned. In conclusion, a dose-dependent increase in markers of growth hormone metabolism and in biochemical markers of both bone and non-bone collagen synthesis was seen following incremental doses of GH in GHD.
Jens Bollerslev, Department of Medical Endocrinology, National University Hospital, N-0027 Oslo, Norway
Somatotrope responsiveness to Hexarelin, a synthetic hexapeptide, is refractory to the inhibitory effect of glucose in obesity
Authors: Grottoli Silvia , Maccario Mauro , Procopio Massimo , Oleandri Salvatore Endrio , Arvat Emanuela , Gianotti Laura , Deghenghi Romano , Camanni Franco , Ghigo Ezio 
Published: December 2008

Grottoli S, Maccario M, Procopio M, Oleandri SE, Arvat E, Gianotti L, Deghenghi R, Camanni F, Ghigo E. Somatotrope responsiveness to Hexarelin, a synthetic hexapeptide, is refractory to the inhibitory effect of glucose in obesity. Eur J Endocrinol 1996;135:678–82. ISSN 0804–4643
Both spontaneous and stimulated growth hormone (GH) secretion is reduced in obesity, in which state insensitivity to the inhibitory effect of hyperglycemiacemia also has been reported. To further investigate this point, in eight male obese (OB) patients (27–49 years old; body mass index = 39.5 ± 1.7 kg/m2) we studied the effect of oral glucose load (100 g) on the GH response to Hexarelin (HEX, 2 μg/kg iv), a synthetic hexapeptide belonging to the GH-releasing peptide family, which has been reported to be able to induce a marked GH rise even in obese patients. As a control group, six male age-matched normal subjects (NS) were studied (26–35 years old; body mass index = 22.3 ± 1.5 kg/m2). In all subjects the GH response to growth hormone-releasing hormone (GHRH, 1 μg/kg iv) was also studied. Basal GH and insulin-like growth factor I (IGF-I) levels in OB and NS were similar (0.3 ± 0.1 vs 0.5 ± 1.0 μg/l and 166.7 ± 12.3 vs 145.4 ± 6.9 μg/l, respectively). Hexarelin induced a clear GH rise in OB (peak: 20.0 ± 2.9 μg/l; AUC: 1193.0 ± 213.7 μg·l−1·120 min−1) but this response was clearly lower (p < 0.0002) than that observed in NS (62.6 ± 7.3 μg/l, 4587.5 ± 614.9 μg·l −1·120 min−1). The GHRH-induced GH rise was lower (p < 0.002) in OB (4.4 ± 1.2 μg/l, 331.0 ± 95.9 μg·l−1·120 min−1) than that in NS (20.2 ± 1.9 μg/l, 1281.0 ± 157.5 μg·l−1·120 min−1) and both were lower (p < 0.05) than those induced by HEX. In NS, glucose significantly blunted the GH response to HEX (38.4 ± 7.2 μg/l, 2236.5 ± 514.8 μg·l−1·120 min−1, p < 0.05) but failed to modify it in OB (19.4 ± 2.7 μg/l, 934.5 ± 151.3 μg·l−1·120 min−1). Plasma glucose peaks after oral glucose load in OB and NS were similar (164.5 ± 9.7 vs 145.8 ± 4.6 mg/dl). In conclusion, the present data demonstrate that, in contrast to normal subjects, in obese patients HEX has a reduced GH-releasing effect that is not inhibited by glucose. In OB patients as well as in normal subjects HEX releases more GH than GHRH. These findings strengthen the evidence that GH secretion in obesity is refractory either to stimulatory inputs or to the inhibitory effect of hyperglycemia.
E Ghigo, Divisione di Endocrinologia, Ospedale Molinette, C.so A.M. Dogliotti 14, 10126 Torino, Italy
Acute stress attenuates but does not abolish circadian rhythmicity of serum thyrotrophin and growth hormone in the rat
Authors: Martí Octavi , Gavaldà Amadeu , John Trinidad , Armario Antonio 
Published: December 2008

Martí O, Gavaldà A, Jolín T, Armario A. Acute stress attenuates but does not abolish circadian rhythmicity of serum thyrotrophin and growth hormone in the rat. Eur J Endocrinol 1996;135:703–8. ISSN 0804–4643
The effects of acute immobilization (IMO) on daily rhythms of corticosterone, thyroid-stimulating hormone (TSH) and growth hormone (GH) were studied in adult male rats. Two hours of IMO increased serum corticosterone, this increase still being observed 3 h after finishing stress exposure. In the dark period corticosterone levels did not differ in control and IMO rats, but higher levels were observed again in the morning of the day after. Immobilization lowered serum GH and TSH levels throughout the 24-h period that followed exposure to the stressor. Such an effect was more marked in GH than in TSH. In addition, GH, but not TSH, levels were found to be reduced significantly by IMO at 08.30 h of the next day. None the less, daily rhythms of GH and TSH were still persistent and roughly similar to those of control rats. The daily rhythm of food intake was measured in a separate experiment and it was observed, as expected, that IMO reduced food intake only in the dark period of the lighting cycle. It appears therefore unlikely that IMO-induced anorexia was the major factor responsible for the inhibition of GH and TSH caused by IMO at 11.00 and 19.00 h, considering that the amount of food intake was very low and similar in control and IMO rats during this period. However, anorexia might have contributed to inhibition of GH and TSH secretion afterwards. Thus, in a third experiment we studied the contribution of IMO-induced anorexia to the changes in hormone levels observed 24 h after stress by introducing a group of pair-fed rats. It was found that IMO, but not pair-feeding, reduced TSH levels, whereas a similar reduction of GH was found in the two conditions. It might be concluded that acute stress transiently altered corticosterone secretion, the only long-lasting effect being a slight increase in its morning levels on the following stress. Immobilization also causes an inhibition of GH and TSH secretion in the rat that persists for several hours after finalization of exposure to the stressor, but daily rhythms were still apparent. It appears that the contribution of stress-induced anorexia is different in GH than in TSH. In conclusion, an acute severe stressor such as IMO, although modifying circulating levels of some hormones, particularly in the hours following exposure to the stressor, did not appear to interfere greatly with the expression of circadian rhythms of anterior pituitary hormones.
Octavi Martí, Unitat de Fisiologia Animal, Facultat de Ciències, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
Post-transcriptional induction of β1-adrenergic receptor by retinoic acid, but not triiodothyronine, in C6 glioma cells expressing thyroid hormone receptors
Authors: López-Barahona Mònica , Iglesias Teresa , García-Higuera Irene , Mayor Federico , Zaballos Angel , Bernal Juan , Muñoz Alberto 
Published: December 2008

López-Barahona M, Iglesias T, García-Higuera I, Mayor Jr F, Zaballos A, Bernal J, Muñoz A. Posttranscriptional induction of β1 -adrenergic receptor by retinoic acid, but not triiodothyronine, in C6 glioma cells expressing thyroid hormone receptors. Eur J Endocrinol 1996:135:709–15. ISSN 0804–4643
Thyroid hormone (triiodothyronine; T3) has been shown to control the expression of β1 -adrenergic receptors (β1-AR) in cardiac myocytes, but not in C6 glioma cells. This cell specificity has been attributed to low expression of T3 receptors and high expression of the c-erbAα2 splice variant that interferes with the action of T3. To check this hypothesis we have expressed the c-erbA/thyroid hormone receptor (TR) α1 gene in C6 glioma cells and investigated their response to thyroid hormone. Cells expressing TRα1, but not wild-type cells, were responsive to T3 as shown by increased expression of mitochrondrial hydroxymethylglutaryl CoA synthase after T3 exposure. However, T3 had no effect on β1-AR gene expression in either set of cells. The β1-AR mRNA concentrations were, however, altered by retinoic acid (RA) treatment. Retinoic acid caused a rapid up-regulation of β1-AR mRNA levels that was blocked by cycloheximide. Retinoic acid did not increase the β1-AR gene transcription rate in run-on experiments. These results indicate an indirect post-transcriptional effect of RA. Control of β1-AR expression in C6 cells is also exerted at the translational level, because there was no correlation between mRNA and protein induction, as determined by radioligand binding studies. We conclude that lack of responsiveness of the β1-AR gene in C6 cells to T3 is not due to high expression of c-erbAα2 but to undefined cell-specific factors.
Alberto Muñoz, Instituto Investigaciones Biomedicas, Arturo Duperier 4, 28029 Madrid, Spain
Dendritic cells and macrophages in the pituitary and the gonads. Evidence for their role in the fine regulation of the reproductive endocrine response
Authors: Hoek A , Allaerts W , Leenen PJM , Schoemaker J , Drexhage HA 
Published: December 2008

Abstract
Blood monocytes are able to mature into macrophages as well as into dendritic cells. Dendritic cells and macrophages have mainly been studied for their function in the immune response, e.g. in the presentation of antigens to lymphocytes and in the phagocytosis/degradation of unwanted material. The cells are also, however, important producers of a variety of signalling molecules and hormones and are thus involved in other physiological functions such as wound healing, the regulation of the microcirculation and the regulation of the function and growth of endocrine cells. This review summarizes the existing evidence for a regulatory role of dendritic cells and macrophages in the function and growth of hormone-producing cells of the pituitary–gonadal axis. It focusses on the presence, localization and phenotype of dendritic cells and macrophages in the anterior pituitary and the gonads, the endocrine regulatory role of cytokines produced by these cells and the existence of putative feedback mechanisms between endocrine cells of the pituitary–gonadal axis and dendritic cells and macrophages. The recognition of a 'floating endocrine-regulatory force' of monocyte-derived cells that also plays a role in the initiation of immune responses has implications for our understanding of the pathogenesis of gonadal and pituitary autoimmune reactions.
European Journal of Endocrinology 136 8–24
Chromogranin A and chromogranin B are sensitive circulating markers for phaeochromocytoma
Authors: Stridsberg Mats , Husebye Eystein S 
Published: December 2008

Abstract
Specific assays for measurements of circulating chromogranin (Cg) A, CgB, CgC and pancreastatin (Ps) have recently been developed. The aim of the present study was to investigate the usefulness of these markers in diagnosing and following the effects of treatment of patients with phaeochromocytoma, and to compare the results with those concerning other biochemical markers. CgA was elevated in 19/21 (90%), CgB in 17/21 (81%), Ps in 9/21 (43%) and neuropeptide Y in 9/21 (43%) of the patients. Urinary noradrenaline was increased in 19/21 (90%) and urinary adrenaline in 17/19 (89%) of the patients. All patients had increased levels of either urinary catecholamines or plasma chromogranins. In one patient levels of CgA, CgB and Ps were measured at frequent intervals before, during and after surgery. The CgA level fell to normal shortly after the tumour was removed, whereas the CgB level decreased towards normal over the course of several days. Significant correlation was observed between the contents of CgA and CgB in the tumour tissue and the plasma levels of CgA and CgB respectively. We conclude that CgA and CgB are sensitive circulating markers for phaeochromocytoma and that measurements of both urinary catecholamines and plasma chromogranins improve the diagnostic sensitivity. Furthermore, measurements of CgA may be useful in assessing the radicality of surgery in the early postoperative period.
European Journal of Endocrinology 136 67–73