bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relation of attenuated proestrous luteinizing hormone surges in middle-aged female rats to in vitro pituitary gonadotropin-releasing hormone responsiveness
Authors: Brito Aurelia N , Sayles Timothy E , Krieg Richard J , Matt Dennis W 
Published: December 2008

Brito AN, Sayles TE, Krieg Jr RJ, Matt DW. Relation of attenuated proestrous luteinizing hormone surges in middle-aged female rats to in vitro pituitary gonadotropin-releasing hormone responsiveness. Eur J Endocrinol 1994;130:540–4. ISSN 0804–4643
Prior to the cessation of regular cyclicity, middle-aged rats display pre-ovulatory luteinizing hormone (LH) surges of reduced magnitude. The present study was designed to identify whether middle-aged female rats with attenuated proestrous LH surges have alterations in pituitary responsiveness to gonadotropin-releasing hormone (GnRH). Young (4 months old) and middle-aged (10–12 months old) regularly cycling females were catheterized and sampled on proestrus to characterize their LH surge profiles. On the next proestrus (12.00 h), pituitaries were perifused individually and exposed to three pulses of GnRH (30 nmol/l). The patterns of the proestrous LH surges revealed that 12 of 22 middle-aged rats had attenuated surges (< 7 μg/l) while the remaining 10 middle-aged females had surges that were similar to those of young rats. Pituitaries perifused on the next proestrus showed similar basal LH release among the middle-aged and young females. However, the LH secretory rates following the second and third administration of GnRH, as well as the overall GnRH-stimulated LH secretory rates, were significantly decreased in middle-aged females with previously attenuated LH surges as compared to those from the young proestrous rats. In contrast, middle-aged rats with normal LH surges had pituitary LH responses that were no different from those of young females. These results indicate that a decrease in pituitary LH responsiveness to GnRH is only apparent in middle-aged rats that display attenuated proestrous LH surges.
Dennis W Matt. Department of Obstetrics and Gynecology, Medical College of Virginia, Box 980034, Richmond, VA 23298, USA
Prevention of iodine deficiency disorders by oral administration of lipiodol during pregnancy
Authors: Chaouki Mohamed L , Benmiloud Moulay 
Published: December 2008

Chaouki ML. Benmiloud M. Prevention of iodine deficiency disorders by oral administration of lipiodol during pregnancy. Eur J Endocrinol 1994;130:547–51. ISSN 0804–4643
The prevalence of iodine deficiency disorders and the thyroid status of the population were studied in an endemic goitre area in Algeria. After oral administration of lipiodol (0.5 ml), three treated groups of mother–newborn couples were compared to an untreated group: group A, mothers treated 1–3 months before conception; group B, mothers treated during the first month of pregnancy; group C, mothers treated during the third month of pregnancy. Untreated mothers were used as a control (group D). After lipiodol treatment, all newborn babies and mothers were clinically euthyroid. All tested newborn babies were full term and no goitre was observed in the four groups. In the mothers, goitre prevalence and thyrotrophin levels decreased significantly, whereas maternal milk and urinary iodine and serum-free thyroxine levels were significantly higher after treatment. The rate of prematurity, stillbirths and abortions in the treated groups was reduced when compared to the untreated group, whereas placental and birth weights were significantly higher. In group D two cases of neonatal hypothyroidism were detected. Their re-evaluation confirmed that hypothyroidism was transient. Groups A, B and C were statistically different from group D with regard to neonatal thyrotrophin and thyroxine. Positive correlations were found between neonatal thyroxine and birth weights and placental weights on the one hand, and maternal urinary iodine and free thyroxine on the other. Consequently, these data indicate that oral administration of lipiodol before or during the first trimester of pregnancy normalizes thyroid function in newborn babies and mothers, increases placental and birth weight and reduces the frequency of iodine deficiency disorders. Lipiodol at this dose and during the first trimester of pregnancy had no deleterious effects and may prevent hypothyroid or neurological cretinism.
Mohamed Lamine Chaouki, Service d'Endocrinologie, Centre Hospitalo-Universitaire de Batna, Route de Tazoult 05000, Batna, Algeria
Cortical bone osteocalcin content and matrix composition in autosomal dominant osteopetrosis type I
Authors: Bollerslev Jens , Marks Sandy C , Mosekilde Lis , Lian Jane B , Stein Gary S , Mosekilde Leif 
Published: December 2008

Bollerslev J, Marks SC, Mosekilde L, Lian JB, Stein GS, Mosekilde L. Cortical bone osteocalcin content and matrix composition in autosomal dominant osteopetrosis type I. Eur J Endocrinol 1994;130:592–4. ISSN 0804–4643
Several bone matrix protein constituents, including the major component collagen type I and the hydroxyapatite binding protein, osteocalcin, have been implicated in the regulation of bone turnover. Corticol bone osteocalcin, collagen and mineral content were studied in autosomal dominant osteopetrosis type I (ADO), a disorder characterized by diffuse symmetrical osteosclerosis, Iliac crest bone biopsies were obtained from eight patients (mean age 43.0 years, range 17–63 years) and compared with 16 age- and sex-matched normal controls (mean age 44.1 years, range 20–61 years). The osteocalcin level in cortical bone was increased (p < 0.03) in ADO (51.4 ± 3.9 mg/kg bone) compared with controls (38.0 ± 3.6 mg/kg bone). Total collagen, protein and calcium expressed per kilogram bone dry weight were without significant difference between patients and controls. The pathogenesis of ADO is most likely not related to cortical bone osteocalcin content, a protein implicated in osteoclast ontogeny and activation. These observations are in contrast to recent observations of reduced bone osteocalcin levels in osteopetrotic mutations in the rat and underscore the interspecies heterogeneity of this disorder.
Jens Bollerslev, Dept. of Med. Endocrinology, National Hospital, Pilestredet 32, N-0027 Oslo, Norway
Short-term starvation increases calcidiol-24-hydroxylase activity and mRNA level in rat kidney
Authors: Hagenfeldt-Pernow Ylva , Ohyama Yoshihiko , Sudjana-Sugiaman Elly , Okuda Kyuichiro , Björkhem Ingemar 
Published: December 2008

Hagenfeldt-Pernow Y, Ohyama Y, Sudjana-Sugiaman E, Okuda K, Björkhem I. Short-term starvation increases calcidiol-24-hydroxylase activity and mRNA level in rat kidney. Eur J Endocrinol 1994;130:608–11. ISSN 0804–4643
The renal mitochondrial calcidiol-24-hydroxylase activity and the corresponding cytochrome P-450 mRNA level were measured in rats subjected to short-term starvation alone or in combination with calcitriol treatment. Short-term starvation of 24 and 48 h increased the mRNA level by five- and six-fold, respectively. The 24-hydroxylase activity increased by five- and threefold, respectively. Treatment with calcitriol markedly increased the enzyme activity about 20-fold and the mRNA level about six-fold. In rats subjected to calcitriol treatment combined with 24 h of starvation, a significant further increase in enzyme activity was observed. The mRNA levels increased but the difference was not significant statistically. The results indicate that the mechanism by which starvation stimulates the enzymes is different, at least in part, from that behind the stimulatory effect of calcitriol.
Y Hagenfeldt-Pernow, Department of Clinical Chemistry L Huddinge University Hospital, S-141 86 Huddinge, Sweden
Role of the serotoninergic system in the control of gonadotropin secretion in prepubertal male rats
Authors: Pinilla Leonor , Ranchal Antonio , Aguilar Rafaela , Aguilar Enrique 
Published: December 2008

Pinilla L, Ranchal A, Aguilar R, Aguilar E. Role of the serotoninergic system in the control of gonadotropin secretion in prepubertal male rats. Eur J Endocrinol 1994;130:617–24. ISSN 0804–4643
To analyze the role of brain serotonin in the control of gonadotropin secretion in prepubertal males, serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) concentrations were studied at different ages after administration of 5-hydroxytryptophan (5-HTP), a precursor of serotonin synthesis, alone or in combination with fluoxetine, a specific inhibitor of serotonin uptake; 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT), a serotonin 1A agonist; or d.l-p-chlorophenylalanine methyl ester hydrochloride (PCPA), an inhibitor of serotonin synthesis. Also, serum gonadotropin concentrations were measured in castrated males implanted with silastic capsules containing testosterone or 5α-androstane-3α, 17β-diol (α-diol). We found that: (i) the blockade of the serotoninergic system after PCPA administration did not modify basal gonadotropin secretion but did strongly reduce the response to orchidectomy; (ii) a stimulatory effect of 5-HTP on FSH secretion was only observed in intact males at the age of 8 days; (iii) the serotonin 1A agonist 8-OH-DPAT did not change serum gonadotropin concentrations; (iv) 5-HTP increased serum FSH and LH concentrations in 16-day-old castrated males; (v) FSH and LH serum concentrations decreased after 5-HTP in castrated animals implanted with testosterone, whereas castrated animals implanted with α-diol showed, like the intact males, a lack of response to 5-HTP. The main conclusions of our work are: (i) the serotoninergic system does not play a major role in the control of gonadotropin secretion in intact prepubertal male rats; (ii) after removal of the testes (s), and with increased FSH and LH serum concentrations, a clear stimulatory action was observed, suggesting that this stimulatory effect is normally masked when gonadotropin secretion is low; (iii) testosterone and its reduced metabolite α-diol affected differently the role of the serotoninergic system on gonadotropin secretion. After 5-HTP administration, gonadotropin secretion was inhibited in castrated males treated with testosterone, while no changes were observed in castrated males treated with α-diol.
Enrique Aguilar, Department of Physiology, Faculty of Medicine, University of Córdoba, E-14004, Spain
Suicide inactivation of aromatase in human placenta and uterine leiomyoma by 5α-dihydronorethindrone, a metabolite of norethindrone, and its effect on steroid-producing enzymes
Authors: Yamamoto Takara , Tamura Takaya , Kitawaki Jo , Osawa Yoshio , Okada Hiroji 
Published: December 2008

Yamamoto T, Tamura T, Kitawaki J, Osawa Y, Okada H. Suicide inactivation of aromatase in human placenta and uterine leiomyoma by 5α-dihydronorethindrone, a metabolite of norethindrone, and its effect on steroid-producing enzymes. Eur J Endocrinol 1994;130:634–40. ISSN 0804–4643
Norethindrone (NET; 17α-ethynyl-19-nortestosterone), a progestogen component of the contraceptive pill, irreversibly inhibits aromatase activity in human placental microsomes. However, it is known also to be aromatized in vitro and in vivo to produce a biologically very active estrogen called ethynylestradiol (EE2). It is therefore inappropriate to administer a high dose of NET to estrogendependent cancer patients for a prolonged time period. In this study, we focused on 5α-dihydronorethindrone (5α-DHNET), a metabolite of NET that is not aromatizable, and the inhibitory effects of 5α-DHNET on human placental and uterine leiomyoma microsomal aromatase and other steroid synthetases. 5α-Dihydronorethindrone showed weak affinity for both estrogen and progestogen receptors. It inhibited significantly human placental aromatase activity in a dose-dependent manner (Ki = 9.0 μmol/l; Kinact = 0.024/min), as well as that of uterine leiomyoma, but did not influence cholesterol side-chain cleavage or 17α-hydroxylase, 21-hydroxylase or 11β-hydroxylase activities. These results suggest that 5α-DHNET may be useful as an aromatase inhibitor, whose use in large doses is expected to reduce the size of estrogen-dependent tumors.
Takara Yamamoto, Department of Obstetrics and Gynecology, Kawaramachi-Hirokoji, Kamikyo-Ku, Kyoto 602, Japan
Long-term treatment of acromegaly with the slow-release somatostatin analogue lanreotide
Authors: Marek Josef , Hána Václav , Kršek Michal , Justová Vlasta , Catus France , Thomas Francois 
Published: December 2008

Marek J, Hána V. Kršek M. Justová V, Catus F, Thomas F. Long-term treatment of acromegaly with the slow-release somatostatin analogue lanreotide. Eur J Endocrinol 1994;131:20–6. ISSN 0804–4643
Thirteen patients with active acromegaly despite previous surgery were treated with 30 mg lanreotide im twice a month for 9 months. In 10 subjects the treatment continued to 19 months. GH serum levels of all patients decreased significantly from an initial value of 32.0 (29.4) μg/l [median (standard error of median)] to 10.0 (3.6) and 19.1 (5.7) after 3 and 9 months of treatment, respectively. In the 10 patients with the treatment longer than one year the decrease in GH was from 46.8 (29.4) μg/l to 12.5 (5.0) and 16.1 (5.3) after 13 and 19 months, respectively. IGF-I serum levels decreased significantly from 1193 (73)μg/l to 782 (99) and 621 (103) after 3 and 9 months, respectively, and were normalized in 3 patients. In the 10 patients treated for longer than one year, levels decreased significantly from 1318 (74)μg/l to 653 (170) and 742 (180) after 13 and 19 months, respectively. IGF BP-3 levels were reduced to the normal range in 6 patients and decreased from 8.7 (1.5)mg/l to 6.4 (0.8) and to 5.4 (1.0) after 3 and 9 months, respectively. In the patients with the 19 months treatment the decrease was from 9.3 (1.6) mg/l to 3.9 (0.9) and 4.8 (0.9) after 13 and 19 months, respectively. The IGF BP-3 to IFG I ratio increased in 7 patients. This elevation significantly correlated with the decrease in bioassayable somatomedin. Prolactin serum levels fell in all patients with increased prolactin secretion. Testosterone plasma levels increased in 4 out of 5 men without replacement therapy. Clinical improvement was observed in all patients. A reduction of tumour mass was observed in five patients and complete disappearance of the tumour in one subject. All patients complained of mild abdominal pain and softened stools for several days following the injections. However, these side effects never required interruption of treatment. Asymptomatic microlithiasis was seen in only one patient after 13 months, which led to treatment being suspended for a period of 3 months after which it was resumed. Fasting serum insulin and insulin area under the curve (AUC) after oral glucose tolerance test (OGTT) fell in all patients. Fasting blood glucose, fructosamine and glucose AUC after OGTT slightly increased during the treatment, but all blood glucose levels (fasting and during OGTT) remained within normal ranges. Lanreotide appears to be a safe and effective treatment in patients with active acromegaly unresolved by surgery. The long-acting formulation avoids the drawbacks associated with either repeated daily injections or continuous infusions of somatostatin analogues.
Josef Marek, Third Department of Medicine, Charles University, U nemocnice 1, 128 21 Praha 2, The Czech Republic
Opioid modulation of the gamma-aminobutyric acid-controlled inhibition of exercise-stimulated growth hormone and prolactin secretion in normal men
Authors: Coiro V , Volpi R , Maffei ML , Caiazza A , Caffarri G , Capretti L , Colla R , Chiodera P 
Published: December 2008

Coiro V, Volpi R, Maffei ML, Caiazza A, Caffarri G, Capretti L, Colla R, Chiodera P. Opioid modulation of the gamma-aminobutyric acid-controlled inhibition of exercise-stimulated growth hormone and prolactin secretion in normal men. Eur J Endocrinol 1994;131:50–5. ISSN 0804–4643
The possible involvement of endogenous opioids in the gamma-aminobutyric acid-controlled (GABAergic) inhibition of growth hormone (GH) and prolactin (PRL) during physical exercise was evaluated in normal men. After fasting overnight, seven subjects were tested on four mornings at least 1 week apart. Exercise was performed on a bicycle ergometer. The workload was gradually increased at 3-min intervals until exhaustion and lasted about 15 min in all subjects. Tests were carried out under administration of placebo, the opioid antagonist naloxone (10 mg as an iv bolus injection), the GABAergic agonist sodium valproate (600 mg in three divided doses orally) or naloxone plus sodium valproate. During exercise, plasma GH and PRL levels rose 5.5- and 1.9-fold, respectively. The administration of naloxone did not modify, whereas sodium valproate significantly reduced the plasma GH and PRL rise during exercise. In the presence of sodium valproate, GH and PRL levels rose 3- and 1.5-fold, respectively, in response to exercise. When naloxone was given together with sodium valproate, both GH and PRL responses to exercise were abolished completely. These data suggest the involvement of a GABAergic mechanism in the regulation of GH and PRL responses to physical exercise in men. Furthermore, the data argue against a role of naloxone-sensitive endogenous opioids in the control of these hormonal responses to exercise, whereas they suggest a modulation by opioids of the GABAergic inhibitory action.
Vittorio Coiro, Istituto di Clinica Medica Generale e Terapia Medica, Università di Parma, via Gramsci 14, 43100 Parma, Italy
Circadian rhythm of hormones is extinguished during prolonged physical stress, sleep and energy deficiency in young men
Authors: Opstad Per Kristian 
Published: December 2008

Opstad PK. Circadian rhythm of hormones is extinguished during prolonged physical stress, sleep and energy deficiency in young men. Eur J Endocrinol 1994:131:56–66. ISSN 0804–4643
The circadian rhythm of hormones (N = 10) and mental performance (N = 18) was investigated in male cadets during a 5-day military training course with continuous heavy physical activities corresponding to 35% of the maximal oxygen uptake, with almost total lack of food and sleep. The 24-h means for androstenedione, dihydroepiandrosterone (DHEA), 17α-hydroxyprogesterone, testosterone and thyroid-stimulating hormone decreased strongly during the course, and the circadian rhythm was extinguished below the minimum levels measured during the control experiment. The 24-h means for cortisol, dihydroepiandrosterone sulfate (DHEA-S) and progesterone increased during the course, and the circadian rhythm was abolished above the maximum levels of the control experiment. A gradual increase was found in thyroxine, free thryoxine and triiodothyronine during the first 12 h of activities, followed by a constant decrease for the rest of the course. Mental performance decreased during the course and the amplitude of its circadian rhythm increased from ±10% to ±30% of the 24-h mean. The circadian rhythms investigated were almost normalized after 4–5 days of rest. However, the nocturnal rise for cortisol, androstenedione and DHEA appeared earlier, and the plasma levels of thyroid hormones, estradiol and DHEA-S were lower during the recovery experiment than in the control experiment. The responses to stress of the circadian rhythm for mental performance and steroid hormones during the course indicate a differential regulation.
Per Kristian Opstad, Norwegian Defence Research Establishment, N-2007 Kjeller, Norway
Simultaneous measurement of plasma 18-oxocortisol and 18-hydroxycortisol levels in normal man
Authors: Yamakita Noriyoshi , Gomez-Sanchez Celso E , Mune Tomoatsu , Morita Hiroyuki , Yoshida Hisashi , Miyazaki Seiji , Yasuda Keigo 
Published: December 2008

Yamakita N, Gomez-Sanchez CE, Mune T, Morita H, Yoshida H, Miyazaki S, Yasuda K. Simultaneous measurement of plasma 18-oxocortisol and 18-hydroxycortisol levels in normal man. Eur J Endocrinol 1994;131:74–9. ISSN 0804–4643
Plasma 18-oxocortisol (18-oxoF) and 18-hydroxycortisol (18-OH-F) were measured in 47 healthy subjects. Plasma 18-oxoF and 18-OH-F in the early morning were 0.827 ± 0.04 nmol/l and 3.29 ± 0.175 nmol/l, respectively. The plasma levels of both steroids correlated with each other and with cortisol, but not with aldosterone. Postural stimulation with or without furosemide administration increased 18-oxoF, 18-OH-F, aldosterone and plasma renin activity (PRA). Two hours after 2 mg of oral dexamethasone administration or after an overnight 2 mg of dexamethasone suppression cortisol, 18-oxoF and 18-OH-F decreased. Cortisol, aldosterone, 18-oxo-F and 18-OH-F increased after the intravenous administration of 250 μg of 1–24 ACTH. Changes in plasma 18-oxo-F and 18-OH-F levels correlated with PRA change during the posture studies and correlated with the change of ACTH during the dexamethasone studies. The ratios of post-/pre-test values of the postural stimulation and dexamethasone suppression in 18-oxoF and 18-OH-F were lower than that of aldosterone. Plasma 18-oxoF and 18-OH-F are more dependent on ACTH than on the reninangiotensin system. The ratio of 18-OH-F/18-oxoF, which is between 4 and 5, remains constant during the various stimulation or suppression maneuvers.
Noriyoshi Yamakita, Department of Internal Medicine, Matsunami General Hospital, Kasamatsu, GifuPrefecture, 501-61 Japan
Treatment of Graves' disease by carbimazole: high dose with thyroxine compared to titration dose
Authors: Edmonds CJ , Tellez M 
Published: December 2008

Edmonds CJ, Tellez M. Treatment of Graves' disease by carbimazole: high dose with thyroxine compared to titration dose. Eur J Endocrinol 1994;131:120–4. ISSN 0804–4643
A comparative study of high-dose (HD, carbimazole 60 mg plus thyroxine 100–150 μg daily) and titration-dose (TD) regimens of carbimazole was carried out in 70 patients with Graves' disease, the patients being assigned randomly to one or other regimen. The treatment was given for 1 year and follow-up was for 2 years after stopping treatment. In both groups, recurrence of hyperthyroidism occurred, most commonly during the first 6 months (35% of HD and 44% of TD). By 2 years after stopping treatment, recurrence had occurred in 50% of the HD and 66% of the TD group. The differences were not significant. Thyroid antibodies, serum thyroglobulin and pertechnetate uptake fell similarly in both groups during treatment. Cigarette smoking was similar in both the groups and did not influence the frequency of relapse. In both HD and TD groups, when relapsing patients were examined according to whether they relapsed early (within 6 months or less) or late it was found that those who relapsed late were, in respect of goitre size, pertechnetate uptake and presence of detectable plasma TSH, similar to the patients who did not relapse at all. In conclusion, the changes in the measured variables and the progress of the patients was similar whether treated by the HD or TD regimen.
CJ Edmonds, Northwick Park Hospital, Watford Road, Harrow, Middlesex HA1 3UJ, UK