bluuebunny/crossref_metadata_2025_split huggingface dataset:
Delayed puberty in males with β-thalassemia major: pulsatile gonadotropin-releasing hormone administration induces changes in gonadotropin isoform profiles and an increase in sex steroids
Authors: Valenti Sandra , Giusti Massimo , McGuinness Dorothy , Guido Roberta , Mori Pier Giorgio , Giordano Giulio , Dahl Kristine Diane 
Published: December 2008

Valenti S, Giusti M, McGuinness D, Guido R, Mori PG, Giordano G, Dahl KD. Delayed puberty in males with β-thalassemia major: pulsatile gonadotropin-releasing hormone administration induces changes in gonadotropin isoform profiles and an increase in sex steroids. Eur J Endocrinol 1995;133:48–56. ISSN 0804–4643
Patients with β-thalassemia major often have pubertal delay, the etiology of which has not been fully elucidated. We investigated the pituitary–gonadal response to short-term subcutaneous pulsatile gonadotropin-releasing hormone (GnRH) administration (150 ng/kg body weight every 120 min for 7 days) in five young males (aged 13.6–19.0 years) affected by β-thalassemia major and presenting signs of delayed puberty. Immunoreactive and bioactive gonadotropin levels were determined and their isoform profiles were examined, before and after GnRH treatment, in a pool of samples collected every 15 min for 240 min. Testosterone, androstenedione, 17-hydroxyprogesterone, dehydroepian-drosterone and 17 β-estradiol were measured as markers of gonadal function on days 0, 1, 3, 5 and 7 of treatment. Five patients (aged 16.9–26.8 years) with confirmed diagnosis of idiopathic hypogonadotropic hypogonadism who were starting pulsatile GnRH therapy were also studied in the same protocol. Increased sex steroid levels were observed in both groups as a result of treatment. On day 7, the thalassemic patients had increased bioactive luteinizing hormone (LH) and follide-stimulating hormone (FSH), although immunoreactive LH and FSH were comparable to day 0. Moreover, fewer acidic and more basic immunoreactive and bioactive isoforms were noted in LH profiles on day 7. Similar results were observed in hypogonadal patients, who also had increased immunoreactive LH and FSH values. We suggest that the early stage of delayed puberty in thalassemia might be characterized by a neuroendocrine dysfunction resulting in an impaired hypothalamic GnRH release, which is inadequate for a proper pituitary stimulation. Pulsatile GnRH treatment seems to re-establish partially the correct pituitary–gonadal function.
Sandra Valenti, Department of Endocrinology and Metabolism, 6 Viale Benedetto XV, 16132 Genoa, Italy
Effects of selenium deficiency on thyroid necrosis, fibrosis and proliferation: a possible role in myxoedematous cretinism
Authors: Contempre Bernard , Dumont Jacques E , Denel Jean-François , Many Marie-Christine 
Published: December 2008

Contempre B, Dumont JE, Denef J-F, Many M-C. Effects of selenium deficiency on thyroid necrosis, fibrosis and proliferation: a possible role in myxoedematous cretinism. Eur J Endocrinol 1995;133:99–109. ISSN 0804–4643
It has been suggested that selenium deficiency is a co-factor to iodine deficiency in the pathogenesis of myxoedematous cretinism. The mechanism proposed is that the generation of hydrogen peroxide is greatly increased in iodine-deficient thyroid glands, and that selenium is involved in the control of hydrogen peroxide and its derived free radicals. This study was carried out to investigate the effect of the possibly impaired cellular defence mechanism associated with selenium deficiency on thyroid necrosis and tissue repair. For this purpose, we studied thyroid tissue from selenium- (SE–) and/or iodine-deficient (I–) rats before and after an acute toxic iodine overload. In I– thyroids, necrotic cells were numerous. Acute iodine administration increased this effect. Necrosis was associated with transient infiltration of inflammatory cells. In 1–SE+ thyroids the tissue resumed its normal appearance. In 1–SE– thyroid glands, the iodide toxicity was stronger, with greater necrosis and inflammatory reaction. The inflammation resolved but was replaced by fibrotic tissue. Fifteen days after the toxic overload, the connective tissue volume was twice the control value. Before iodide overload, the proportion of dividing cells was equal in 1–SE+ and 1–SE– thyroids. Three days after the iodide overload, this proportion was increased in 1–SE+ thyroids but reduced in the 1–SE– thyroids. Overall, the 1–SE– thyroids had four times fewer dividing cells than the 1–SE+ thyroids. In summary, selenium deficiency coupled to iodine deficiency increased necrosis, induced fibrosis and impeded compensatory epithelial cell proliferation. These results are compatible with histological and functional descriptions of thyroid tissue from myxoedematous cretins.
B Contempre, IRIBHN, C.P. 602, Free University of Brussels, Medicine Faculty, 808 route de Lennik, B-1070 Brussels, Belgium
Comparative effects of food restriction, fasting, diabetes and thyroidectomy on growth hormone and thyrotropin gene expression in the rat pituitary
Authors: Rodriguez Manuela , Rodriguez Felipe , Jolin Trinidad , Santisteban Pilar 
Published: December 2008

Rodriguez M, Rodriguez F, Jolin T, Santisteban P. Comparative effects of food restriction, fasting, diabetes and thyroidectomy on growth hormone and thyrotropin gene expression in the rat pituitary. Eur J Endocrinol 1995;133:110–6. ISSN 0804–4643
To examine the molecular basis for the decreased pituitary growth hormone (GH) and thyrotropin (TSH) content during restricted feeding, fasting and diabetes, we measured steady-state levels of mRNA for TSH-α TSH-β and GH in the pituitary from normal rats either fed ad libitum (C), limited to 75%, 50% and 25% (FR75, FR50, FR25, respectively) of ad libitum intake, or deprived of food for 2 and 4 days (F2 and F4, respectively), and also in streptozotocin-diabetic (D) and D insulin-treated animals. The results from these experimental groups were compared with those in thyroidectomized (Tx) rats. Pituitary mRNA was quantified by Northern blot hybridization with cDNA probes specific for rat TSH-α, TSH-β and GH. Although changes in the pituitary GH mRNA during restricted feeding, fasting and diabetes were similar qualitatively to those induced by hypothyroidism, GH mRNA levels in Tx rats (> 10% of C values) were less than in the other experimental groups (p < 0.001). Pituitaries from FR50, FR25 and D rats also contained less GH mRNA than F2 and F4 animals (p < 0.05). Thyroidectomy resulted in a marked increase in both TSH-β and TSH-α mRNAs, the changes in TSH-β mRNA being greater than those in TSH-α mRNA. In contrast, FR50, FR2 5, F2, F4 and D rats exhibited a decrease in pituitary TSH-β mRNA (60%, 50%, 35%, 36% and 33%, respectively, of C values; p < 0.01–0.05) and in TSH-α mRNA levels (81%, 64%, 46%, 43% and 36%, respectively, of normal values; p < 0.02–0.05), TSH-β mRNA showing the greater changes. However, pituitaries from F2, F4 and D rats contained less TSH-β and TSH-α mRNA levels than FR50 and FR25 animals (p < 0.05). Insulin therapy partially restored the changes in mRNA for GH, TSH-β and TSH-α observed in D rats. In addition, the pituitary nuclear triiodothyronine in Tx, FR50, FR25, F2, F4 and D rats was reduced to 19%, 73%, 52%, 76%, 51% and 41%, respectively of C values (p < 0.05–0.001). These data suggest that GH, TSH-α and TSH-β gene expression are modulated by metabolic and/or endocrine changes accompanying restricted feeding, fasting and diabetes.
P Santisteban, Instituto de Investigaciones Biomédicas, CSIC, Arturo Duperier 4, 28029 Madrid, Spain
Effects of V1- and V2-vasopressin (AVP) antagonists on the pressor, AVP and atrial natriuretic peptide responses to a hypertonic saline infusion in conscious anephric rats
Authors: Ota Kozo , Kimura Tokihisa , Inoue Minoru , Funyu Takeharu , Shoji Masaru , Sato Kazutoshi , Ohta Masahiro , Yamamoto Tadasu , Abe Keishi 
Published: December 2008

Ota K, Kimura T, Inoue M, Funyu T, Shoji M, Sato K, Ohta M, Yamamoto T, Abe K, Effects of V1- and V2-vasopressin (AVP) antagonists on the pressor, AVP and atrial natriuretic peptide responses to a hypertonic saline infusion in conscious anephric rats. Eur J Endocrinol 1995;133:127–32. ISSN 0804–4643
To examine the role of vasopressin (AVP) receptors in the regulation of the hemodynamics and release of atrial natriuretic peptide (ANP), and the participation of renal nerve inputs in the osmotic AVP release, hypertonic saline (HS) was infused into conscious, bilaterally nephrectomized rats with nonpeptide, selective antagonists for the V1-receptor or V2-receptor of AVP. In the control group, HS alone increased mean arterial pressure, plasma ANP and AVP, plasma volume and plasma osmolality, and decreased the heart rate. In the V1-receptor antagonist group, an increase in the mean arterial pressure and a decrease in heart rate were completely abolished and an increase in plasma ANP was attenuated. In the V2-receptor antagonist group, increases in mean arterial pressure and plasma ANP and a decrease in heart rate were attenuated. However, the ratio of the changes in heart rate to the changes in mean arterial pressure in the V2-receptor antagonist group is significantly higher than that in the control group. In both experimental groups, increases in plasma AVP, plasma volume and plasma osmolality were not different from those in the control group. These results suggest that a HS-induced increase in mean arterial pressure is mediated by the pressor effect of AVP, mainly through V1-receptors, and that the depressor effect of AVP through V2-receptors may not influence tonically HS-induced hypertension. Moreover, HS-induced increase in plasma ANP is mediated mainly by increases in plasma volume and blood pressure, but may not be affected by a direct action of AVP to the heart. Renal afferent nerve inputs may not have effects on the regulation of osmotic AVP release.
Kozo Ota, Second Department of Internal Medicine, Tohoku University School of Medicine, 1-1 Seiryo-cho, Aoba-ku, Sendai 980-77, Japan
Plasma brain natriuretic peptide concentrations in healthy children from birth to adolescence: marked and rapid increase after birth
Authors: Yoshibayashi Muneo , Kamiya Tetsuro , Saito Yoshihiko , Nakao Kazuwa , Nishioka Kenya , Temma Shinji , Itoh Hiroaki , Shirakami Gotaro , Matsuo Hisayuki 
Published: December 2008

Yoshibayashi M, Kamiya T. Saito Y. Nakao K, Nishioka K, Temma S, Itoh H, Shirakami G, Matsuo H. Plasma brain natriuretic peptide concentrations in healthy children from birth to adolescence: marked and rapid increase after birth. Eur J Endocrinol 1995;133:207–9. ISSN 0804–4643
The aim of the present study is to establish the normal range and to determine the developmental changes of plasma brain natriuretic peptide (BNP) concentrations in children. We measured plasma BNP concentrations as well as atrial natriuretic peptide (ANP) concentrations in 58 healthy children from birth to adolescence and in the umbilical vein of 20 healthy neonates using highly sensitive immunoradiometric assays. The plasma BNP concentration was the highest at 0 days of age and descended through maturation to be almost constant and to be at the adult level at 3 months of age. The plasma BNP concentration at 0 days of age (56.7 ± 49.6 fmol/ml; mean±sd) was 25 to 30 times higher than the adult level and 21 times higher than that in the umbilical vein (2.7 ± 1.4fmol/ml), The plasma ANP concentration at 0 days of age was not significantly different from that in the umbilical vein. The ratio of BNP to ANP was also the highest at 0 days of age (1.39 ± 0.72) and decreased through maturation to be at the adult level at 3 months of age. Thus, the plasma BNP concentration in healthy subjects showed a marked, rapid and preferential increase immediately after birth, suggesting that BNP has a physiological role distinct from that of ANP in the perinatal circulatory changes from fetus to neonate.
Muneo Yoshibayashi, Department of Pediatrics, National Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka 565, Japan
Insulin-like growth factor I does not inhibit insulin secretion in adult human pancreatic islets in tissue culture
Authors: Eizirik Décio L , Skottner Anna , Hellerström Claes 
Published: December 2008

Eizirik DL, Skottner A, Hellerström C. Insulin-like growth factor I does not inhibit insulin secretion in adult human pancreatic islets in tissue culture. Eur J Endocrinol 1995;133:248–50. ISSN 0804–4643
Insulin-like growth factor I (IGF-I) has been found to increase insulin sensitivity and suppress insulin secretion, thereby having a potential interest as a therapeutic agent for non-insulin-dependent diabetes mellitus (NIDDM). The aim of the present study was to investigate the direct actions of IGF-I (400 ng/ml) on human pancreatic islets, or on rat pancreatic islets, during a 48 h period in tissue culture. Insulin-like growth factor I did not affect medium insulin accumulation, DNA or insulin content or short-term glucose-induced insulin release of human islets. However, in rat islets the peptide induced a significant decrease in the insulin increase ratio in response to 16.7 mmol/l glucose. In conclusion, the present data suggest that IGF-I does not directly affect the function of human pancreatic β-cells If this in vitro data can be extrapolated to the in vivo situation, it suggests that the observed inhibitory effects of IGF-I on serum insulin levels may be secondary to peripheral effects of the peptide.
Décio L Eizirik, Department of Medical Cell Biology, Biomedicum, PO Box 571, S-751 23 Uppsala, Sweden
Role for serotonin3 receptors in the control of adrenocorticotropic hormone release from rat pituitary cell cultures
Authors: Calogero Aldo E , Bagdy Gyorgy , Burrello Nunziatina , Polosa Pietro , D'Agata Rosario 
Published: December 2008

Calogero AE, Bagdy G, Burrello N, Polosa P. D'Agata R. Role for serotonin3 receptors in the control of adrenocorticotropic hormone release from rat pituitary cell cultures. Eur J Endocrinol 1995;133:251–4. ISSN 0804–4643
Although several serotonin (5-HT) receptor types have been shown capable of stimulating the release of adrenocorticotropic hormone (ACTH) from the pituitary gland, relatively little is known about the role of the 5-HT3 receptor, a receptor that has generated a great deal of interest for its involvement in many behavioral and therapeutic effects. Hence, in this study, we tested the effects of the 5-HT¾ receptor antagonist 3-tropanyl-indole-3-carboxylate (ICS 205-930) and the selective 5-HT3 receptor antagonist 3-tropanyl-3,5-dichlorobenzoate (MDL 72222) on ACTH release stimulated by 5-HT from primary cultures of rat pituitary cells. Subsequently, we evaluated the effects of the selective 5-HT3 receptor agonist 1-(m-chlorophenyl)-biguanide (m-CPBG) on basal, corticotropin-releasing hormone (CRH)- and arginine vasopressin (AVP)-stimulated ACTH release. The maximal stimulatory effect of 5-HT (10−9 mol/l on ACTH release was antagonized by both ICS 205-930 and MDL 72222, suggesting that 5-HT stimulates basal ACTH release through activation of 5-HT3 receptors. Accordingly, m-CPBG stimulated basal ACTH release in a concentration-dependent fashion. In contrast to 5-HT, m-CPBG did not have any effect on CRH-stimulated ACTH release and inhibited AVP-stimulated ACTH release in a concentration-dependent manner. These data suggest that the 5-HT3 receptor is involved in the release of ACTH from the pituitary gland in vitro.
Aldo E Calogero, Istituto di Clinica Medica I, Ospedale Garibaldi, Piazza S Maria di Gesú, 95123 Catania, Italy
Effect of restraint stress on the preovulatory luteinizing hormone profile and ovulation in the rat
Authors: Roozendaal Marjolijn M , Swarts Hans JM , Wiegant Victor M , Mattheij John AM 
Published: December 2008

Roozendaal MM, Swarts HJM, Wiegant VM, Mattheij JAM. Effect of restraint stress on the preovulatory luteinizing hormone profile and ovulation in the rat. Eur J Endocrinol 1995;133:347–53. ISSN 0804–4643
Plasma profiles of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured during restraint stress on the day of pro-oestrus; these profiles were considered in relation to ovulation rate on the next day. Rats bearing a permanent jugular vein cannula were subjected to restraint, which was started 0, 1 or 2 h before the presumed onset of the LH surge and ended just before the beginning of the dark period. Exposure to restraint resulted in a suppression of the secretion of both gonadotrophins on the day of pro-oestrus. Suppression of the LH surge was virtually complete (plasma LH ≤ 0.2 ng/ml) in 15 out of 32 stressed rats, and the ovaries of these rats contained graafian follicles with oocytes in germinal vesicle stage. In these rats, the LH surge did not occur 24 h later. In the remaining 17 rats, restraint resulted in a considerable suppression of the LH surge. Of these rats, five had an ovulation rate of 100% and four ovulated partially. In unruptured follicles of the latter, the oocyte had not resumed meiosis and the follicle wall was not luteinized. In the remaining eight rats with a reduced LH surge, ovulations had not occurred and graafian follicles were unaffected. The results of this study indicate that during pro-oestrus restraint stress suppresses and does not delay the release of preovulatory gonadotrophins. Partial suppression of LH by restraint does not result in induction of meiotic resumption without subsequent ovulation or in luteinized unruptured follicles.
JAM Mattheij, Department of Human and Animal Physiology, Agricultural University, Haarweg 10, 6709 PJ, Wageningen, The Netherlands
Evidence for a role for the neurosteroid allopregnanolone in the modulation of reproductive function in female rats
Authors: Genazzani Andrea R , Palumbo Marco A , de Micheroux Antonio A , Artini Paolo G , Criscuolo Mario , Ficarra Guido , Guo Ai-Li , Benelli Augusta , Bertolini Alfio , Petraglia Felice , Purdy Robert H 
Published: December 2008

Genazzani AR, Palumbo MA, de Micheroux AA, Artini PG, Criscuolo M, Ficarra G, Guo A-L, Benelli A, Bertolini A, Petraglia E. Purdy RH. Evidence for a role for the neurosteroid allopregnanolone in the modulation of reproductive function in female rats. Eur J Endocrinol 1995;133:375–80. ISSN 0804–4643
The present study investigated the effect of allopregnanolone (5α-pregnan-3α-ol-20-one) or of passive immunoneutralization of brain allopregnanolone, the most potent steroid produced by neurons, on ovulation rate and sexual behavior in female rats. Allopregnanolone was injected intracerebroventricularly in rats on diestrus and proestrus and tests were done on estrus. The intracerebroventricular injection of allopregnanolone significantly decreased the number of oocytes collected on estrus (p < 0.01). To support a physiological involvement, antiserum to allopregnanolone was injected centrally to block the activity of the endogenous neurosteroid. When administered on diestrus and proestrus or only on proestrus, the antiserum was shown to be correlated with a significant increase (p < 0.01) in oocytes retrieved on estrus. In female rats treated with antiserum to allopregnanolone, the lordosis intensity was augmented significantly as compared to controls. Finally, the possible changes of medial basal hypothalamus concentration of allopregnanolone throughout the estrous cycle and at the time of ovulation were investigated. Hypothalamic extracts were eluted on highpressure liquid chromatography and allopregnanolone concentration was measured by radioimmunoassay. Brain cortex was used as control tissue. Hypothalamic allopregnanolone concentration on proestrus morning and afternoon was found to be significantly lower than in the remaining phases of the estrous cycle (p < 0.01), while no significant changes were observed in brain cortex concentration of allopregnanolone. The present results suggest that hypothalamic allopregnanolone may be involved in the mechanism of ovulation, affecting hormonal and behavioral events.
AR Genazzani, Institute of Obstetrics and Gynecology, University of Pisa, via Roma 67, 56100 Pisa, Italy
Effects of treatment with octreotide in acromegalic patients—a multicenter Italian study
Authors: Arosio Maura , Macchelli Sonia , Rossi Cristina M , Casati Giovanni , Biella Orietta , Faglia Giovanni 
Published: December 2008

Arosio M, Macchelli S, Rossi CM, Casati G, Biella 0, Faglia G, the Italian Multicenter Octreotide Study Group. Effects of treatment with octreotide in acromegalic patients—a multicenter Italian study. Eur J Endocrinol 1995:133:430–9. ISSN 0804–4643
Treatment of acromegaly is effective in reversing the reduced life-span of patients only when serum growth hormone (GH) concentrations are lowered to less than 2.5 μg/l. Usual treatments achieve this goal in no more than 50–60% of patients. The effects of octreotide were studied in a prospective, open label study with 68 acromegalic patients enrolled in 10 Italian centers. Octreotide was administered sc at a dose of 100 μg t.i.d. for 1 year. After 3 months of therapy, octreotide was effective in decreasing serum GH levels below 2.5 μg/l in 16 out of 64 acromegalic patients (25%). Fifteen of them had pretreatment GH levels below 25 μg/l. Insulin-like growth factor I (IGF-I) levels normalized in about 40% of patients. No further GH reduction was observed after 1 year of treatment. The presence of abnormal GH responses to thyrotropin-releasing hormone (TRH) and gonadotropin-releasing hormone was reduced from 54 to 24% and from 16 to 12%, respectively. Tumor shrinkage was observed in 50% of 26 non-irradiated patients after 12 months of treatment. Both basal and TRH-stimulated serum prolactin levels significantly decreased in the 11 hyperprolactinemic patients. Although serum thyrotropin, free triiodothyronine and free thyroxine concentrations were not modified, a significant reduction of thyrotropin response to TRH was observed in the 9th month of therapy. In non-diabetic patients, an increase of mean blood glucose levels without modifications of fasting morning concentrations was found. About one-quarter of the patients with overt diabetes mellitus had an impairment of their metabolic control. Main clinical symptoms of acromegaly improved in 70–80% of patients. An 18% decrease of low-density-lipoprotein cholesterol and unchanged high-densitylipoprotein cholesterol levels were observed in 35 patients studied. Triglyceride levels decreased in patients with hypertriglyceridemia pretreatment. Regarding side effects, gallstones were newly diagnosed in five patients, three patients dropped out because of severe diarrhea and two diabetic patients dropped out due to worsening of their metabolic control. In conclusion, octreotide is an effective treatment of acromegaly, mainly in patients with moderate elevation of serum GH levels. The drug has also been proved to positively affect dyslipidemia.
Maura Arosio, Institute of Endocrine Sciences, Ospedale Maggiore IRCCS, Pad. Granelli, Via F Sforza 35, 20122 Milano, Italy