bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exogenous free iodotyrosine inhibits iodide transport through the sequential intracellular events
Authors: Nasu Michiyo , Sugawara Masahiro 
Published: December 2008

Nasu M, Sugawara M. Exogenous free iodotyrosine inhibits iodide transport through the sequential intracellular events. Eur J Endocrinol 1944;130:601–7. ISSN 0804–4643
We describe a new function of exogenous iodotyrosine as a regulator of iodide transport. Porcine thyroid follicles in culture were preincubated with 0–20 μmol/l monoiodotyrosine or diiodotyrosine (DIT) in the presence of bovine thyrotropin (TSH) for 24 h; these iodotyrosines inhibited iodide uptake in a dose–response manner. Extracellular [125I]DIT was actively transported to the thyroid follicle in the presence of TSH or (Bu)2cAMP. Inhibition of iodide uptake by iodotyrosine required preincubation with iodotyrosine in the presence of TSH; without TSH, iodotyrosine was ineffective. Follicles preincubated with DIT for 24 h inhibited TSH-mediated cAMP production, which is an important signal for iodide transport. Inhibition of iodide uptake and cAMP generation by iodotyrosine was negated characteristically by 3-nitro-l-tyrosine, an inhibitor of iodotyrosine deiodinase, or by methimazole, an inhibitor of thyroid peroxidase. Our findings suggest that iodotyrosine regulates iodide transport through the following sequential intracellular events: TSH-dependent iodotyrosine transport into the thyroid cell; deiodination of iodotyrosine and release in iodide; iodine organification by the peroxidase system; inhibition of cAMP generation by organified iodine; and inhibition of iodide transport. Thus, exogenous iodotyrosine can serve as an inhibitor of thyroid hormone formation only when TSH is present
M Sugawara, Wadsworth VA Hospital (11 IM), Wilshire and Sawtelle Blvds, Los Angeles, CA 90073, USA
Pancreatic and islet blood flow in F1-hybrids of the non-insulin-dependent diabetic GK-Wistar rat
Authors: Svensson Annika M , Abdel-Halim Samy M , Efendic Suad , Jansson Leif , Östenson Claes-Göran 
Published: December 2008

Svensson AM, Abdel-Halim SM, Efendic S, Jansson L, Östenson C-G. Pancreatic and islet blood flow in F1 -hybrids of the non-insulin-dependent diabetic GK-Wistar rat. Eur J Endocrinol 1994:130:612–16. ISSN 0804–4643
Previous studies have indicated that various conditions under which an increased functional load is posed on the pancreatic islets, e.g. partial pancreatectomy and continuous glucose infusions, may influence the microcirculation of the pancreas. To investigate further the effects of elevated functional demand on the islets, the blood perfusion of the whole pancreas and the pancreatic islets was measured with a microsphere technique in an animal model presenting impaired glucose tolerance and mild hyperglycemia, namely F 1-hybrids of the spontaneously non-insulin-dependent diabetic GK-Wistar rat. Normal Wistar rats served as controls. All hybrids had a pathological intraperitoneal glucose tolerance test 1 week before the blood flow measurements, which were performed in 10–12-week-old rats. Both the whole pancreatic and the islet blood flows were increased in the hybrids compared to controls. The fractional islet blood flow, i.e. the fraction of whole pancreatic blood flow diverted through the islets, also was increased in the hybrid rats (12.6 ±0.6% vs 9.8 ±0.5% in controls, p <0.01). A bilateral abdominal vagotomy performed 30 min before the blood flow measurement markedly decreased the blood flow values of the islets and the whole pancreas in both groups of rats. After vagotomy, the islet blood flow in the hybrid rats was similar to that of the vagotomized control animals (8.2 ± 0.8 and 7.5 ± 1.4%, respectively). It is concluded that the increased pancreatic and islet blood perfusion observed in F 1-hybrids of the GK-Wistar rat depends on a mechanism mediated by the vagus nerve.
Annika M Svensson, Department of Medical Cell Biology, Biomedical Centre, PO Box 571, S-75123 Uppsala, Sweden
Effect of corticotrophin-releasing hormone administration on growth hormone levels in acromegaly: in vivo and in vitro studies
Authors: Colao Annamaria , Merola Bartolomeo , Ferone Diego , Calabrese Maria Rosaria , Longobardi Salvatore , Spaziante Renato , Renzo Gianfranco Di , Annunziato Lucio , Lombardi Gaetano 
Published: December 2008

Colao A, Merola B, Ferone D, Calabrese MR, Longobardi S, Spaziante R, Di Renzo G, Annunziato L, Lombardi G. Effect of corticotrophin-releasing hormone administration on growth hormone levels in acromegaly: in vivo and in vitro studies. Eur J Endocrinol 1994;131:14–19. ISSN 0804–4643
The ability of CRH to cause a paradoxical response of GH in acromegaly is still under debate. In this study, the effect of CRH administration on GH release was evaluated in a large series of patients with active acromegaly, both in vivo, compared to that of TRH and GnRH, and in vitro. The study was organized as follows. In vivo study: 30 acromegalic patients were submitted to TRH, GnRH, and CRH tests on non-consecutive days: blood samples were collected before and 10, 20, 30, 45, 60, 90, and 120 min after bolus. In nine patients the CRH test was repeated after a 3-month therapy with octreotide and at the dose of 300–600 μg sc thrice daily. In vitro study: CRH (10 nmol/l, 100 nmol/l, and 1 μmol/l) was tested on pituitary tumor tissue obtained in eight patients during transsphenoidal adenomectomy and immediately placed in sterile Ca2+ and Mg2+ free buffer phosphate. A paradoxical GH response to TRH (evaluated as a GH increase over 50% of basal values) was recorded in 19 patients (63.3%), whereas 7 patients (23.3%) responded to GnRH and 4 others to CRH (13.3%). TRH administration induced a maximal percent GH increase significantly greater than that induced by GnRH and CRH (p < 0.05). Octreotide caused the normalization of GH and insulin-like growth factorI levels in all the patients, as well as the disappearance of the GH paradoxical response to CRH in 3/4 patients. All four CRH responders and four CRH non-responders, used as controls, were surgically treated and adenomatous tissue was used for the in vitro study. No significant GH increase was found in the CRH non-responders and in the three CRH responders in whom the GH paradoxical response to CRH disappeared during octreotide treatment. Conversely, a significant GH increase (over 250% of pre-incubation values) after CRH administration was found in the remaining case. In conclusion, the results of the present study show that CRH is rarely able to stimulate paradoxical GH response in patients with active acromegaly and that the in vivo recorded GH release after CRH is in vitro reproducible only in extremely rare cases.
Annamaria Colao, Corso Europa 63, 80127 Napoli, Italy
Effects of repeated subcutaneous administration of recombinant human insulin-like growth factor I in adults with growth hormone deficiency
Authors: Thorén Maria C , Wivall-Helleryd Inga-Lena , Blum Werner F , Hall Kerstin E 
Published: December 2008

Thorén MC, Wivall-Helleryd I-L. Blum WF, Hall KE. Effects of repeated subcutaneous administration of recombinant human insulin-like growth factor I in adults with growth hormone deficiency. Eur J Endocrinol 1994;131:33–40. ISSN 0804–4643
Insulin-like growth factor I (IGF-I) circulates bound to specific binding proteins (BPs) that modulate its effects at target cells. Hypoglycemia alters the serum levels of insulin-dependent IGFBPs and thus modifies the IGF-I action. We administered recombinant IGF-I (40 μg/kg body wt, from Kabi Pharmacia) in a morning dose (08.00 h) for seven consecutive days to six patients (21–47 years) with panhypopituitarism. This dose did not lead to hypoglycemia. Repeated blood sampling was performed on days 1 and 7, otherwise morning samples were drawn. The mean serum total IGF-I was maximal 3–4 h after the injection. A higher peak and basal value (p < 0.05) was observed on day 7 when compared to that observed on day 1. The concentrations were 237 vs 190 μg/l and 43 vs 22 μg/l. The mean free IGF-I increased concomitantly to 17 and 20 μg/l after 2–3 h on days 1 and 7. After 4 h, IGF-II was decreased (p <0.05) from 340 to 291 μg/l on day 1 and from 341 to 252 μg/l on day 7. The IGF-I area under the curve on days 1 and 7 was correlated to the IGFBP-3 levels. Only the patient with the highest IGFBP-3 level obtained IGF-I levels above 100 μg/l for 24 h. In spite of unchanged glucose levels, there was a modest suppression of insulin levels (p < 0.05) between 0 and 4 h from 102 to 78 pmol/l on day 1 and from 90 to 60 pmol/l on day 7 when the subjects were fasting. A small decline of mean potassium concentrations was found 2–6 h after the injection on day 1. During a week with daily injections, the morning serum IGF-I increased slightly in comparison to basal levels but no significant change in morning values of IGFBP-1, -2, -3, glucose and insulin were observed. Serum urea, creatinine, cholesterol and free fatty acid decreased significantly, indicating metabolic effects of IGF-I. Thus IGF-I has metabolic effects in doses not leading to hypoglycemia. To achieve a normal diurnal IGF-I level, recombinant IGF-I should be administered two or three times per 24 h in subjects with subnormal IGFBP-3 levels.
Marja Thorén, Department of Endocrinology and Diabetology, Karolinska Hospital, S-171 76 Stockholm, Sweden
The relationship between plasma osmolality and plasma vasopressin concentration is altered in old male Lewis rats
Authors: Terwel Dirk , Jolles Jellemer 
Published: December 2008

Terwel D, Jolles J. The relationship between plasma osmolality and plasma vasopressin concentration is altered in old male Lewis rats. Eur J Endocrinol 1994;131:86–90. ISSN 0804–4643
Kidney dysfunction has been observed in aged humans and rats, the primary cause of which may reside in the kidney itself or in the hypothalamus. The latter possibility is suggested by the increased release of AVP in response to salt infusion in humans. The effect of age on the relationship between plasma osmolality and plasma AVP concentration has never been verified in an animal model. Therefore, in the present study, 9% salt solution was infused into adult and aged Lewis rats, and plasma AVP concentration and osmolality were measured. Basal plasma AVP concentration, osmolality and total water intake were not altered in aged Lewis rats as compared with adult animals, indicating the absence of overt disturbances in water homeostasis. Infusion of 9% salt solution resulted in a linear increase in plasma osmolality in both adult and aged rats. Plasma osmolality increased more with time in aged animals than in adult animals, suggesting an age-related difference in kidney function during salt infusion. Plasma AVP concentration increased 50% less with osmolality at relatively low osmolalities, but not at relatively high osmolalities. The altered relationship between plasma osmolality and plasma AVP concentration in rats with age may be related to changes in neurons monitoring osmolality or to changes in baroreflex regulation. The data suggest that reduced kidney function with age does not result from an altered relationship between plasma osmolality and plasma AVP concentration.
D Terwel, University of Limburg, Department of Neuropsychology and Psychobiology, PO Box 616, 6200 MD Maastricht, The Netherlands
Pharmacological characterization and autoradiographic localization of dopamine receptors in the human adrenal cortex
Authors: Amenta Francesco , Chiandussi Livio , Mancini Maurizio , Ricci Alberto , Schena Marina , Veglio Franco 
Published: December 2008

Amenta F, Chiandussi L, Mancini M, Ricci A, Schena M, Veglio F. Pharmacological characterization and autoradiographic localization of dopamine receptors in the human adrenal cortex. Eur J Endocrinol 1994;131:91–6. ISSN 0804–4643
The pharmacological characteristics and the anatomical localization of dopamine D1-like and D2-like receptors were studied in sections of the human adrenal cortex using radioligand binding and autoradiographic techniques. [3H]SCH23390 was used as a ligand of D1-like receptors, whereas [3H]spiroperidol was used to label D2-like receptors. No specific [3H]SCH 23390 binding was detectable in sections of the human adrenal cortex. On the other hand, [3H]spiroperidol was bound to sections of the adrenal gland in a manner consistent with the labelling of dopamine D2-like receptor sites. The binding was time, temperature and concentration dependent, belonging in the range of concentrations of the radioligand used for a single class of high-affinity sites. The dissociation constant (Kd) averaged 2.7 nmol/l, whereas the maximum density of binding sites (Bmax) was 160 nmol/mg tissue. Experiments on the pharmacological specificity of [3H]spiroperidol binding to sections of the human adrenal cortex revealed that clozapine was the most powerful displacer of [3H]spiroperidol from sections of the human adrenal cortex. This suggests the presence in the human adrenal cortex of dopamine receptors of the D4 subtype. Light microscope autoradiography showed the highest density of specific [3H]spiroperidol binding sites in the zona glomerulosa and to a lesser extent in the zona reticularis. Only sparse [3H]spiroperidol binding sites were localized in the zona fasciculata. The possible functional consequences of this localization of dopamine D2-like receptor sites in the human adrenal cortex are discussed.
Francesco Amenta, Istituto di Farmacologia, Via Scalzino 5, 62032 Camerino, Italy
Anti-obesity effect of CL 316,243, a highly specific β3-adrenoceptor agonist, in mice with monosodium-l-glutamate-induced obesity
Authors: Yoshida Toshihide , Sakane Naoki , Wakabayashi Yasuo , Umekawa Tsunekazu , Kondo Motoharu 
Published: December 2008

Yoshida T. Sakane N, Wakabayashi Y, Umekawa T, Kondo M. Anti-obesity effect of CL 316,243, a highly specific β3-adrenoceptor agonist, in mice with monosodium-l-glutamate-induced obesity. Eur J Endocrinol 1994;131:97–102. ISSN 0804–4643.
The effects of CL 316,243, a highly specific β3-adrenoceptor agonist (relative selectivities of 0, 1 and 100000 for β1-, β2- and β3-receptors, respectively), were evaluated in mice with monosodium l-glutamate (MSG)-induced obesity as well as in control mice injected with physiological saline instead of MSG. Both MSG- and saline-treated mice were divided into three groups and at 8 weeks of age received either CL 316,243 (0.1 or 1.0 mg/kg) or distilled water through a gastric tube for 2 weeks. CL 316,243 not only reduced white adipose tissue mass but also activated brown adipose tissue and systemic metabolism, and hence reduced body mass without affecting food intake. Furthermore, CL 316,243 decreased hyperglycemia and hypertriglyceridemia in MSG-treated mice. However, at the higher dose, CL 316,243 also increased liver triglyceride in MSG-treated mice. These observations suggest that CL 316,243 exerts an anti-obesity effect in mice with MSG-induced obesity and consequently may prove efficacious in the treatment of human obesity.
Toshihide Yoshida, First Department of Internal Medicine, Kyoto Prefectural University of Medicine, 465-Kajiicho, Hirokoji-Kawaramachi, Kamikyo-ku, Kyoto 602, Japan
Reduction in size of a thyrotropin-secreting pituitary adenoma treated with octreotide acetate (somatostatin analog)
Authors: Lee Eun Jig , Kim Kyung Rae , Lim Sung Kil , Lee Hyun Chul , Kim Dong Ik , Kim Sun Ho , Huh Kap Bum 
Published: December 2008

Lee EJ, Kim KR, Lim SK, Lee HC, Kim DI, Kim SH, Huh KB. Reduction in size of a thyrotropin-secreting pituitary adenoma treated with octreotide acetate (somatostatin analog). Eur J Endocrinol 1994;131: 109–12. ISSN 0804–4643
We present a 55-year-old female with a thyrotropin (TSH)-secreting pituitary adenoma who had been treated with somatostatin analog octreotide acetate (SMS 201–995) for 4 months. Subcutaneous injection of 100 μg octreotide acetate twice daily resulted in significant reduction of the TSH, thyroid hormone, and tumor size. During the treatment, there was no evidence of any side effects. We may conclude that octreotide acetate administration is an effective treatment in patients with TSHsecreting pituitary adenoma for suppressing TSH hypersecretion and reducing the size of the tumor.
Eun Jig Lee, Division of Endocrinology, Department of Internal Medicine, Yong Dong Severance Hospital, Youngdong PO Box 1217, Seoul 135-270, Korea
Echographic diagnosis of pretibial myxedema in patients with autoimmune thyroid disease
Authors: Salvi Mario , De Chiara Flavia , Gardini Eliana , Minelli Roberta , Bianconi Lina , Alinovi Alberto , Ricci Roberto , Neri Fabrizio , Tosi Claudio , Roti Elio 
Published: December 2008

Salvi M, De Chiara F, Gardini E, Minelli R, Bianconi L, Alinovi A, Ricci R, Neri F, Tosi C, Roti E. Echographic diagnosis of pretibial myxedema in patients with autoimmune thyroid disease. Eur J Endocrinol 1994;131:113–19. ISSN 0804–4643
In the present study we have evaluated the use of pretibial ultrasound for the diagnosis of pretibial myxedema (PTM). We studied 76 patients, 58 with Graves' disease, 13 with Hashimoto's thyroiditis and five with idiopathic hypothyroidism. Thirty-two normal subjects were also studied as controls. Sixty-four patients had associated ophthalmopathy. The ultrasound scanner was equipped with 10-and 13-MHz probes. Punch biopsies were carried out in 11 patients and tissue sections examined on a light microscope. On clinical examination 21 patients (28%) had suspected PTM. By ultrasound, we measured the thickness of dermis and subcutaneous tissue (Dl) and that including only deeper dermis (D2) in normal subjects to define the echographic parameters of normal pretibial skin. We then found increased skin thickness in 25 patients (33%), with mean Dl and D2 values significantly higher than those measured in controls (p < 0.00001). The echographic study was positive in 20 patients with ophthalmopathy (31%). Ultrasound showed increased skin thickness in 16 of 21 patients (76%) with clinically suspected PTM. Histopathological findings confirmed the presence of PTM in all the patients who underwent pretibial skin biopsy. We believe that the measurement of pretibial skin thickness by ultrasound may be useful for revealing the presence of PTM.
Mario Salvi, Cattedra di Endocrinologia, Università di Parma, Via Gramsci 14-43100 Parma, Italy
Antithyroid effects in vivo and in vitro of babassu and mandioca: a staple food in goiter areas of Brazil
Authors: Gaitan Eduardo , Cooksey Robert C , Legan Jim , Lindsay Raymond H , Ingbar Sidney H , Medeiros-Neto Geraldo 
Published: December 2008

Gaitan E, Cooksey RC, Legan J, Lindsay RH, Ingbar SH, Medeiros-Neto G. Antithyroid effects in vivo and in vitro of babassu and mandioca: a staple food in goiter areas of Brazil. Eur J Endocrinol 1994;131:138–44. ISSN 0804–4643
Babassu (Orbignya phalerata), a palm-tree coconut fruit, mixed with mandioca (Manihot utilissima) is the staple food of people living in the endemic goiter area of Maranhao in Brazil, where goiter prevalence among schoolchildren was still 38% in 1986 despite an adequate iodine intake in most of the population. Therefore, the question arose as to whether or not the ingestion of babassu alone or mixed with mandioca contributed to the persistence of endemic goiter in this area of Brazil. In this investigation we examined the potential antithyroid effects of babassu and mandioca by means of in vivo studies in Sprague-Dawley rats, in vitro studies in porcine thyroid slices and using a purified porcine thyroid peroxidase (TPO) system. Samples of various edible parts of babassu and mandioca flour were homogenized and extracted in goitrogen-free water (GFW) for in vivo experiments, and in methanol (100 g/l), GFW or 0.06 mol/l phosphate buffer (pH 7.0) for in vitro experiments. The edible parts of babassu produced significant in vivo antithyroid effects (p < 0.05–< 0.001) in rats on a high iodine intake (14 μg I− day−1 · rat−1), as well as distinct and reproducible antithyroid and anti-TPO activities in both in vitro systems, their action being similar to that of the thionamide-like antithyroid drugs propylthiouracil and methimazole. The antithyroid action of aqueous extracts of mandioca flour in vivo and in thyroid slices in vitro was also evident by significant (p < 0.01–< 0.001) and pronounced inhibition of the iodide organification process; however, in contrast to babassu, methanol and aqueous extracts of mandioca flour caused little inhibition in vitro in the TPO system. Little or no effect was produced by babassu or mandioca on thyroid iodide transport by thyroid slices or in vivo in the rat, indicating that neither thiocyanate nor perchlorate-like compounds are responsible for their antithyroid effects. Results of this study provide direct experimental evidence, both in vivo and in vitro, of antithyroid effects of babassu and mandioca, supporting the hypothesis that this staple food is responsible, at least in part, for the persistence of goiter in the iodine-supplemented endemic region of Maranhao in Brazil.
Eduardo Gaitan, Endocrinology Section (151), VA Medical Center, 1500 E. Woodrow Wilson Drive, Jackson, MS 39216, USA
Increased prevalence of colonic adenomas in patients with acromegaly
Authors: Vasen Hans FA , van Erpecum Karel J , Roelfsema Ferdinand , Raue Friedhelm , Koppeschaar Hans , Griffioen Gerrit , van Berge Henegouwen Gerard P 
Published: December 2008

Vasen HFA, van Erpecum KJ, Roelfsema F, Raue F, Koppeschaar H, Griffioen G, van Berge Henegouwen GP. Increased prevalence of colonic adenomas in patients with acromegaly. Eur J Endocrinol 1994;131:235–7. ISSN 0804–4643
Forty-nine acromegalics and 57 controls matched for age and sex underwent colonoscopy. The control group consisted of patients investigated because of atypical abdominal complaints compatible with irritable bowel syndrome or constipation. The exclusion criteria for both groups included: age over 75 years, previous colonic polyps or cancer, previous colonic surgery, rectal blood loss, anemia, previous abdominal radiation, sigmoidoscopy, colonoscopy or barium enema performed for any indication within 3 years prior to the present study. Colonoscopy was successful in reaching the cecum in 72 and 77% of the controls and acromegalics, respectively (p = NS). Eleven (22%) of 49 acromegalics had biopsy-proven colonic adenomas versus only five (9%) of the control group (p≤0.05). Multiple adenomas were found in three of the 11 acromegalics and in none of the controls. In five of these 11 patients and in only one of the controls, at least one adenoma was located in the right colon. In addition, acromegalics tended to have larger adenomas. The group of acromegalics with and without adenomas did not differ significantly in age or duration of active disease. In conclusion, the present study shows that acromegalic patients have an increased risk of developing colonic adenomas.
HFA Vasen, Department of Gastroenterology, Leiden University Hospital, Rijsnburgerweg 10, 2333 AA Leiden, The Netherlands