bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variation in the release of thyroxine, triiodothyronine and growth hormone in response to thyrotrophin releasing hormone during development of the domestic fowl
Authors: Decuypere E. , Scanes C. G. 
Published: December 2008

Abstract.
In newly hatched chicks, TRH administration was followed by increased circulating concentrations of growth hormone (GH), thyroxine (T4) and 3,3',5-triiodothyronine (T3). Little change in the circulating concentration of 3,3',5'-triiodothyronine (rT3) was however observed. The effect of TRH on the circulating concentration of GH was not found in chick embryos at 17 or 19 days of incubation but was observed during pipping. The T4 response was maximal in newly hatched chicks and present in 17 and 19 days embryos. The magnitude of the T3 responses increased with age while that of T4 decreased.
The effect of thyrotrophin-releasing hormone (TRH) on pancreatic hormone secretion in normal subjects
Authors: Ø. Dolva L. , Hanssen K. F. , Flaten O. , Hanssen L. E. , von Schenck H. 
Published: December 2008

Abstract.
Thyrotrophin-releasing hormone (TRH) is present in the pancreas, mainly in the islets of Langerhans.
We studied the effect of iv infused TRH on the plasma levels of pancreatic islet hormones in man, under different experimental conditions:
1) Arginine infusion.
2) Insulin induced hypoglycaemia.
3) Glucose clamp technique (maintainance of normoglycaemia by glucose infusion during insulin infusion).
4) TRH injection.
Except for a minor inhibition of glucagon and pancreatic polypeptide following hypoglycaemic stimulation in one study, TRH had no significant effect on basal, stimulated or inhibited plasma glucagon, on insulin, somatostatin, pancreatic polypeptide or blood glucose.
It is concluded that iv administration of TRH does not produce significant changes in peripheral plasma levels of pancreatic hormones.
Application of techniques, which allow studies closer to the pancreatic islet, is probably necessary to assess the role of TRH in the regulation of endocrine pancreas.
CuZn superoxide dismutase, Mn superoxide dismutase, catalase and glutathione peroxidase in lymphocytes and erythrocytes in insulin-dependent diabetic children
Authors: Hägglöf Bruno , Marklund Stefan L. , Holmgren Gösta 
Published: December 2008

Abstract.
CuZn superoxide dismutase, Mn superoxide dismutase, catalase and glutathione peroxidase activities in lymphocytes and erythrocytes were studied in 9 children with insulin-dependent diabetes mellitus (IDDM) as well as in 21 healthy children. The mean erythrocyte CuZn superoxide dismutase and glutathione peroxidase were statistically significantly lower in the IDDM group compared with the controls although almost all IDDM results fell within the mean ± 2 sd limits of the controls. The small differences found can hardly be assigned biological significance. Erythrocyte catalase as well as lymphocyte CuZn superoxide dismutase and Mn superoxide dismutase did not differ from the controls.
Reductions in plasma catecholamines and blood pressure during weight loss in obese subjects
Authors: Tuck Michael L. , Sowers James R. , Dornfeld Leslie , Whitfield Larry , Maxwell Morton 
Published: December 2008

Abstract.
The effect of weight reduction on levels of upright plasma norepinephrine (NE) and epinephrine (E) was studied in 20 obese patients maintained on a hypocaloric protein diet. Subjects were divided into 2 groups on either a constant 120 (N=13) or 40 (N=7) mmole sodium intake. Initial upright NE levels were higher (P < 0.001) in obese subjects (610 ± 52 pg/ml) than in non-obese controls (325 ± 25 pg/ml). Initial NE in obese subjects correlated (r=0.6, P < 0.01) with mean arterial pressure. Weight loss in both sodium intake groups was accompanied by a progressive decline in upright NE and by 8 weeks levels were decreased in all study subjects by a mean of 42 per cent (P < 0.01) from baseline. Reductions in upright E from baseline were not as pronounced but were significant (P < 0.05) at 8 weeks on both sodium intakes. We have previously shown that mean arterial pressure and PRA decrease significantly in obese subjects during supplemented fasting independent of sodium intake. In the present study reductions in body weight correlated (r=58, P < 0.05) with both the fall in NE levels at 8 weeks (r=0.5, P < 0.05) and with reduction in upright PRA (r=0.49, P < 0.05) at weeks 4 to 8. Changes in upright E did not correlate with weight and blood pressure reductions. We conclude that reduction in caloric intake in obese patients is accompanied by significant reductions in upright NE and E that may contribute to the decline in resting blood pressure. The decrease in upright PRA with weight loss could result from depression in sympathetic nervous system activity.
Active and inactive renin in primary and secondary adrenal insufficiency and during ACTH infusion
Authors: Belkien Lutz , Exner Petra , Oelkers Wolfgang 
Published: December 2008

Abstract.
Prolonged low-dose ACTH infusion leads to a transient stimulation of plasma renin activity (PRA) and angiotensin II.
In part 1 of the present study (infusion of 10 IU of ACTH per day for 38 h into 6 normal young males), it was shown that the concentration of active renin (aPRC) increases in parallel to PRA. Thus, the rise in PRA is either due to net active renin secretion by the kidney or to increased conversion of inactive into active renin. Since the plasma concentration of inactive renin (iPRC) tended to rise rather than to fall during ACTH infusion, peripheral activation of inactive renin is probably not the cause of the rise in aPRC.
Part 2 of the study consisted in the measurement of plasma ACTH, cortisol, PRA, aPRC and iPRC in 10 patients (group I) with primary adrenocortical insufficiency (8 Addisonians, 2 adrenalectomized Cushing's) and in 9 patients with hypopituitarism (group II) after short-term withdrawal of hydrocortisone substition therapy. ACTH was 1770 ± 390 pg/ml in the former and 20 ± 4 pg/ml in the latter group. PRA and aPRC were higher and the ratio iPRC:aPRC lower in group I than in group II. This might indicate stimulation of active renin formation by ACTH. However, it is unlikely that the higher aPRC levels in group I are due to increased peripheral activation of inactive renin, since the relationship between aPRC and the ratio iPRC:aPRC fell on the same curve in both groups.
ACTH or an ACTH-dependent mechanism raises aPRC, probably by stimulating its renal secretion rather than by peripheral activation of inactive renin.
Increased serum reverse triiodothyronine in patients with hyperemesis gravidarum
Authors: Juras N. , Banovac K. , Sekso M. 
Published: December 2008

Abstract.
Thyroid function and pituitary responsiveness to TRH were studied in patients with hyperemesis gravidarum.
Serum T3 and T4 concentrations were normal. Serum TBG levels in hyperemesis were normal for gestation, and the T4: TBG ratio was in the euthyroid range. In all patients a normal TSH response to TRH was found.
Mean serum rT3 concentration was increased by 31% as compared to a control group of normal pregnant women (P< 0.001).
The data suggest that in patients with hyperemesis gravidarum there is: (a) normal function of the thyroid gland and pituitary-thyroid axis, (b) an enhanced peripheral conversion of T4 to rT3.
Ram hypothalamic - pituitary - gonadal - interactions. Effects of castration and cryptorchidism
Authors: Caraty A. 
Published: December 2008

Abstract.
The changes in hypothalamic LRH content, serum levels of LH, FSH and testosterone, and pituitary gonadotrophin contents were systematically compared in three experiments with rams. The first experiment was designed to identify specific endocrine changes at 15, 30 or 180 days after castration; the second, the influence of injections of testosterone (2 × 30 mg/day) for 15 days in castrated rams and the third, the effects of surgical cryptorchidism.
The rapid decrease in plasma testosterone levels after castration (P < 0.05) was associated with an increase in plasma gonadotrophins (P < 0.01). By 2 weeks post-castration, hypothalamic LRH content was significantly reduced. This reduction (∼ 60% of intact controls) remained unchanged at 30 and 180 days after castration. In the second experiment the post-castration rise of plasma gonadotrophins was entirely prevented by testosterone administration and no difference was observed in hypothalamic LRH content of intact control and testosterone treated castrate rams. In the third experiment cryptorchidism induced a significant increase in plasma gonadotrophins which was intermediate between those of intact and castrate rams. Pituitary gonadotrophin content increased in cryptorchid rams without a concomitant change in hypothalamic LRH content.
The data show that:
1) the mode of regulation of pituitary gonadotrophin concentration differs from that observed in the rat,
2) factors other than testosterone are implicated in the regulation of gonadotrophin secretion and synthesis and,
3) testosterone supplementation was able to maintain a normal hypothalamic LRH content.
Differences in the hepatic and renal extraction of insulin and glucagon in the dog: evidence for saturability of insulin metabolism
Authors: Polonsky K. , Jaspan J. , Emmanouel D. , Holmes K. , Moossa A. R. 
Published: December 2008

Abstract.
The metabolism of exogenously infused porcine insulin and glucagon was assessed concurrently in normal fasted dogs under anaesthesia. Hepatic and renal extraction of glucagon were 25.6 ± 2.3 and 43.7 ± 3.9 %, respectively, and its metabolic clearance 16.5 ± 0.8 ml/kg/min. Hepatic and renal extraction accounted for 28.5 ± 4.2 and 28.7 ± 3.7% of total glucagon clearance, respectively. Insulin MCR was 18.3 ± 1.5 ml/kg/min and its hepatic and renal extraction were 49.6 ± 3.4 and 41.7 ± 4.4% accounting for 51.9 ± 4.4 and 27.3 ± 3.9% of total insulin clearance, respectively. Neither total glucagon metabolic clearance nor its hepatic or renal components saturated even in the face of circulating glucagon levels extending into the pharmacologic range up to 14 ng/ml. In contrast however, with increasing arterial concentrations of insulin, saturability of metabolism was apparent as evidenced by significant reductions in MCR as well as hepatic and renal extraction. This demonstration of saturability of hepatic insulin metabolism occurred at levels encountered in the portal vein after meals and is compatible with the concept that the hepatic capacity for extraction of this hormone may be an important site of control of the proportion of secreted insulin reaching the periphery.
The metabolic handling of each hormone was shown to be independent of the other. Despite similarities in the interaction of insulin and glucagon with the target cell, there are important differences in the mechanisms of metabolism of these peptides at the major degradative sites.
Prolonged remission of a case of Cushing's disease following cessation of cyproheptadine therapy
Authors: Wiesen M. , Ross F. , Krieger D. T. 
Published: December 2008

Abstract.
A case of a patient with Cushing's disease is presented who underwent clinical and laboratory remission after the initiation of cyproheptadine therapy and who has sustained such a remission for more than 3 years after discontinuing the drug.
Serotonin stimulates prolactin secretion in the hypophysectomized adenohypophyseal grafted rat
Authors: Stobie K. M. , Shin S. H. 
Published: December 2008

Abstract.
Normal male, oestrogen (E2) primed male and hypophysectomized adenohypophyseal grafted male rats (HAG rats) were used in the experiments. Serotonin creatinine sulphate was injected as a bolus via an indwelling atrial cannula in the conscious free moving rat. Serotonin caused a dose-dependent increase in plasma prolactin (Prl) in normal (1, 3 and 10 mg/kg serotonin) and E2 primed (1 and 3 mg/kg serotonin) male rats that began immediately after injection and reached a peak within 12–15 min of injection. Oestrogen priming significantly increased the magnitude of the response to serotonin. To analyze the site of action of serotonin in the rat, serotonin (1 mg/kg) was injected into HAG rats. Serotonin increased plasma Prl in this rat preparation, indicating that serotonin acts directly on the ectopic pituitary.
Relation between plasma insulin and blood glucose in a cross-sectional population study of the oral glucose tolerance test
Authors: Berntorp K. , Trell E. , Thorell J. , Hood B. 
Published: December 2008

Abstract.
In a material of 3596 oral glucose tolerance tests (OGTT) performed in a population investigation of middle-aged males in Malmö, fasting and 120 min values of blood glucose and plasma insulin immunoreactivity (IRI) were studied while taking factors like body weight, smoking, alcohol, gastric resection and selfreported diabetes heredity into account. The fasting as well as the 120 min levels of both glucose and IRI were markedly influenced by body weight and smoking habits but not by the hereditary background. At 120 min, but not in the fasting state, there was a linear correlation between the IRI and glucose levels. The increase of IRI on glucose was significantly steeper in most of the hereditary subjects in comparison with their non-hereditary controls.
Sites of RNA synthesis and migration in the adrenal cortex cells of the young rat, as shown by radioautography
Authors: Magalhães Maria C. , Magalhães M. M. , Coimbra A. 
Published: December 2008

Abstract.
The sites of RNA synthesis, processing and migration were studied with light and electron microscope radioautography in adrenal zona fasciculata cells of the young rat. Animals were injected iv with [3H]uridine and sacrificed at various time intervals. A marked radioactive peak was found in blood at the 20 min interval, later time intervals being considered as chase periods. Labelling was high over nucleoli of fasciculata cells at 1 h, with the silver grains concentrated over the fibrillar component. Simultaneous though lower peaks occurred over the condensed chromatin and the interchromatin space. Nucleolar and extranucleolar values were decreased at 8 and 24 h, most silver grains overlaying the cytoplasm at this time period. At 8 h, the granular component of the nucleolus was more heavily labelled than the fibrillar component.
This sequence of events suggests a relatively slow uptake of the labelled nucleotides and slow formation of pre-rRNA molecules in the fibrillar component of the nucleolus, with the processing into smaller subunits occurring in the granular component during initial chase. Extranucleolar RNAs were synthesized simultaneously but in a smaller rate. Most nucleolar RNA was finally transferred to the cytoplasm. This pattern will serve as a basis for studying the effects of ACTH on the different steps of RNA synthesis and transport in adrenal cortex cells.
Serum concentrations of gonadotrophins in hypergonadotrophic patients following stimulation by a long-acting analogue of luteinizing hormone-releasing hormone
Authors: Vierhapper H. , Waldhäusl W. , Klaushofer G. , Stackl W. 
Published: December 2008

Abstract.
The effect of D-Ser(TBU)6-EA10-LRH, a long-acting analogue of luteinizing hormone-releasing hormone (LRH), was studied in patients with hypergonadotrophism due to orchidectomy (n = 8) or due to Klinefelter's syndrome (n = 6). Patients orchidectomized less than 7 days prior to the administration of the compound presented with maximum concentrations of LH (63.8 ± 29.9 mIU/ml) within 60 min following iv injection of the LRH-analogue (10 μg). This behaviour of LH was qualitatively similar to that seen in healthy men. In patients orchidectomized more than 40 days prior to the administration of the LRH-analogue and in patients with Klinefelter's syndrome the occurrence of maximum serum LH-concentrations (115.0 ± 39.4 and 149.4 ± 134.5 mIU/ml, respectively) was delayed up to 240–360 min following iv LRH-analogue. This pattern of LH secretion is similar to that of healthy women. No qualitative differences in stimulated FSH-concentrations were observed between the described groups of hypergonadotrophic patients. These findings demonstrate a time-dependent increase in the 'second pool' of LH following orchidectomy. The similar behaviour of stimulated LH-release in healthy women and in male patients with long-term hypergonadotrophic hypogonadism could indicate an augmented production of endogenous LRH in these individuals as compared to healthy men, providing an explanation for the sexually related differences in the LH-response upon the administration of the LRH-analogue.
Altered Leydig cell function in patients with testicular cancer: evidence for a bilateral testicular defect
Authors: Willemse P. H. B. , Sleijfer D. Th. , Sluiter W. J. , Koops H. Schraffordt , Doorenbos H. 
Published: December 2008

Abstract.
In search of an abnormality in Leydig cell function in patients with testicular cancer, serum levels of testosterone, oestradiol, LH and FSH were compared in 3 groups of men.
Group I comprised 26 patients studied after recent orchidectomy for a testicular carcinoma, group II 8 patients operated for benign testicular lesions and group III 8 normal controls. In group II normal testosterone values were found as a result of increased LH release. In group I patients, however, testosterone levels often were low, despite elevated LH levels and increased LH capacity. Evidently, in these patients a partial Leydig cell insufficiency may be present, which does not recover within one year of orchidectomy.
After removal of one testis for benign disease, normal testosterone levels are maintained by increased LH levels. After orchidectomy for testicular carcinoma a partial Leydig cell insufficiency may be revealed, which seems to have a permanent character. A pre-existent Leydig cell insufficiency of the remaining testis in patients with testicular cancer indicates a bilateral testicular defect.
17-ketosteroid reductase deficiency in an adult patient without gynaecomastia but with female psychosexual orientation
Authors: Millán M. , Audí L. , Martinez-Mora J. , de Osaba M.J. Martinez , Viguera J. , Esmatjes E. , Peig M. , Vilardell E. 
Published: December 2008

Abstract1
A 24 years old male with pseudohermaphroditism due to a deficiency in 17-ketosteroid reductase activity is described. Plasma Δ4 is 21 times higher than normal for an adult male, Δ4/T is greater than 6, both E1 and E2 are elevated and E1/E2 = 3.
There is very slight modification of Δ4 on administration of ACTH, dexamethasone, hCG and fluoxymesterone. Steroid concentrations in the spermatic veins and arteries confirm the testicular origin of the increased secretion of Δ4 and E1 and show a lower secretion by the cryptorchidic testis.
In vitro testicular tissue incubation and fibroblast studies confirm the 17-ketosteroid reductase deficiency and rule out any other anomaly as the cause of the ambiguous genitalia.
Psychologically the patient seemed to be identified with a female social and sexual role in spite of her advanced degree of virilization.
Effects of KCIO4 in propylthiouracil-hypothyroid rats
Authors: Ortiz-Caro Javier , Pastor Rosa M. , Jolin Trinidad 
Published: December 2008

Abstract. In this study we investigated further the antigoitrogenic effect of ClO4 in rats on a low iodine diet (LID) and 6-propyl-2-thiouracil (PTU). The thyroid weight of rats on the mixed goitrogen was initially similar to that of animals on PTU, decreasing to values obtained in rats treated with ClO4 alone by 10 days. Despite the differences in thyroid weight, rats treated during an identical period with PTU or mixed goitrogen develop hypothyroidism to a comparable degree as far as can be assessed by the thyroidal 127I content, plasma T4, T3 and TSH concentrations, and pituitary TSH content. Moreover, it was observed that there were differences in plasma insulin and glucose levels in these hypothyroid animals. The plasma insulin and glucose levels of rats on PTU are comparable to those found in control rats. In rats on mixed goitrogen, both plasma insulin and glucose levels are initially maintained within the normal ranges, and then decline over the subsequent days of treatment. Within the treatment period studied here, plasma insulin and glucose levels were higher for rats on PTU than for animals on ClO4, PTU + ClO4, or thyroidectomized (Th) animals.
We have obtained further evidence of the hypothyroid state of rats on these goitrogen regimens based on measurements of pituitary and plasma GH levels and liver mitochondrial alpha-glycerophosphate dehydrogenase (α-GPD). The PTU-treatment decreased the liver α-GPD activity to a comparable degree to that of mixed goitrogen. Moreover, both PTU + ClO4 and PTU-treatment resulted in a state of hypothyroidism intense enough to induce effects on growth, and plasma and pituitary GH levels comparable to that of Th animals. However, the values for rats on mixed goitrogen appear to be below the PTU data. The present findings appear to be consistent with the view that TSH is not the unique factor determining the size of the resulting goitre. The results are discussed in relation to the hypothesis that: 1) the antigoitrogenic effect of ClO4 could be associated with changes in the ability of the thyroid tissue to bind TSH, or with a step beyond TSH binding, and 2) the different endocrine and metabolic states of rats on PTU or PTU + ClO4, shown by their different plasma insulin, GH and glucose levels, may play an important role in determining the thyroid weight response to TSH.
Maximum calorie (sub-threshold) dieting of the obese and its hormonal response
Authors: Wilkin T. J. , Choquet R. C. , Schmouker Y. , Rouquette N. , Baldet L. , Vannereau D. 
Published: December 2008

Abstract. Severe calorie restriction for treating the obese reduces serum triiodothyronine (T3) and energy expenditure, and may be counterproductive. In order to avoid severe calorie deficiency, we measured the individual minimum energy requirements (threshold, T) in 17 obese females and fed each on a sub-threshold diet, comprising the maximum number of calories commensurate with weight loss (T-200 cals). Mean T-200 was 1318 ± 96 cals, but the mean weight loss after 16 weeks on a sub-threshold diet (STD) was identical (17 kg) to that obtained by 22 age-matched female controls on a classical diet of 659 ± 59 cals, exactly half the intake. Weight loss on the classical diet was initially rapid but decelerated sharply after 8 weeks, while on the sub-threshold diet the rate of loss remained constant throughout.
In a second study, thyroid hormone measurements were performed three times weekly in 27 obese females during the 4 week period required to establish T. The mean weight loss was 4.02 ± 0.3 kg, but T3 levels varied minimally and very transiently. STD produces short-term results similar to those obtained by severe calorie deprivation, but is more acceptable to the patient. It appears not to provoke the fat-saving reflexes provoked by the classical, low-calorie diet.
Iodide enhances IgG synthesis by human peripheral blood lymphocytes in vitro
Authors: Weetman A. P. , McGregor A. M. , Campbell H. , Lazarus J. H. , Ibbertson H. K. , Hall R. 
Published: December 2008

Abstract. Several studies have suggested that iodide may increase thyroiditis and autoantibody synthesis. We have investigated the effect of iodide in vitro at physiologically relevant concentrations on immunoglobulin synthesis by normal human peripheral blood lymphocytes stimulated with pokeweed mitogen.
Both the number of cells which synthesised IgG and the amount of IgG released into the culture supernatant increased significantly after culture in a medium with added iodide compared to a medium with added chloride. No effect of increasing concentrations of the added iodide from 10−3 mm to 10 mm was observed.
These findings suggest that iodides may have a role in enhancing antibody synthesis which may be important when programmes of iodide supplementation are introduced into areas which are deficient.