bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of thymidine incorporation activity in the sera from patients with short stature
Authors: Nakazawa Takako , Okada Yoshiaki , Kato Yukio , Suzuki Fujio , Kumahara Yuichi
Published: December 2008

Serum activity that stimulates DNA synthesis was determined in 130 patients of short stature, 6 with acromegaly, and 5 with anorexia nervosa, using a technique to measure [3H]thymidine incorporation into cultured human fibroblasts. The stimulation of thymidine incorporation into the fibroblasts, abbreviated as thymidine incorporation activity (TIA), was significantly lower than normal (P < 0.001) in 18 untreated children with GH-deficiency (0.63 ± 0.14 U/ml, mean ± sd), and in 5 patients with anorexia nervosa (0.58 ± 0.18), but higher than normal (P < 0.05) in 5 untreated acromegalic patients (1.30 ± 0.15). Pooled control serum from normal adult subjects was defined as having activity of 1 unit/ml of TIA. The mean TIA level of 6 untreated children with GH deficiency increased to normal (0.99 ± 0.26) in the last month of treatment with human growth hormone (KABI-hGH), and that of 5 acromegalic patients decreased to normal or less (0.89 ± 0.20) after transsphenoidal hypophysectomy. There was a good correlation (r = 0.54, P < 0.001) between the TIA level and increase in height of 47 GH-deficient children treated with hGH. The TIA values in 22 blod samples obtained from 6 untreated children with GH-deficiency and 16 GH-deficient children treated with hGH were well correlated with values of measurements of [3H]thymidine incorporation into cultured growing chondrocytes of rabbits (r = 0.65, P < 0.001).

These results suggest that serum activity to stimulate [3H]thymidine incorporation into human fibroblasts has GH dependency, and should be a reliable index in bioassay of total somatomedin-like bioactivity in serum.
A hormonally controlled serum factor stimulating the thymidine uptake into lectin-activated lymphocytes
Authors: Thieriot-Prévost Geneviève , Schimpff Rose-Marie , Sharif A.
Published: December 2008

The in vitro stimulation of [3H]thymidine uptake into lectin-activated lymphocytes in the presence of various sera was studied. The mean precision of the assay is 5%, and the study of the confidence intervals shows variations from 4% to 12%. Compared to a normal reference serum (fixed as 1 U/ml), the serum thymidine uptake stimulating activity (mean ± sem) was 1.04 ± 0.07 U/ml in normal adult males, 2.63 ± 0.48 U/ml in acromegalic patients, 1.51 ± 0.13 U/ml in constitutional dwarfism and 0.37 ± 0.04 U/ml in untreated hypopituitary dwarfism with a significant difference between the groups (P < 0.001). In patients with hypopituitarism a single im hGH dose (6 mg/m2) increased the thymidine uptake stimulating activity of serum within 24 to 48 h following injection. The effects of directly adding hGH, insulin and T3 to the assay, have been studied: pharmacological concentrations are required to produce only a slight effect. Physiological concentration of a purified preparation of somatomedin A stimulated thymidine uptake and its effect is increased in the presence of serum. These data demonstrate that [3H]thymidine uptake into lectin-activated lymphocytes is stimulated by a GH-dependent serum factor. The data suggest that this method should be proposed for an accurate and sensitive biological evaluation of serum thymidine uptake stimulating activity.
Prognostic value of thyrotrophin binding inhibiting immunoglobulins (TBII) in longterm antithyroid treatment, 131I therapy given in combination with carbimazole and in euthyroid ophthalmopathy
Authors: Bliddal Henning , Kirkegaard Carsten , Siersbæk-Nielsen Kaj , Friis Thorkild
Published: December 2008

Thyrotrophin binding inhibiting immunoglobulins (TBII) were measured in 27 patients with Graves' disease during and after longterm antithyroid treatment. The median observation period after treatment was 24 months. During the first 6 months of treatment the TBII index increased significantly in both the relapse and the remission group, but during the rest of the treatment and the observation no further change was observed. Patients with a TBII index below 0.35 at drug withdrawal (n = 8) all relapsed and patients with values above 1.00 (n = 5) all stayed in remission. There was a significant correlation between the TBII index at drug withdrawal and the time elapsed before a relapse. Graves' disease was treated with 131I in combination with carbimazole in 22 patients. The TBII index of these patients decreased after 131I and increased towards normal values during longterm observation of median 33 months. Of 4 patients with euthyroid ophthalmopathy one was TBII positive. This patient became overt hyperthyroid after an observation period of two years of prednisone treatment. It is concluded, that the TBII index is of some prognostic value after longterm antithyroid treatment, but is of no clinical importance following 131I treatment.
Iodine metabolism and the effect of TSH in thyroid glands of early bovine embryos
Authors: Avivi A. , Shemesh M. , Lindner H. R.
Published: December 2008

The ontogeny of the thyrotrophin-thyroid axis during the first trimester was studied in 104 bovine embryonic thyroids taken from foetuses of crown-rump length 1.4 to 19.2 cm (25–120 days). The uptake of labelled iodine in vitro in the absence or presence of TSH was measured. The per cent incorporation of radioiodine into iodotyrosines and iodothyronines in the presence and absence of TSH was also studied. It was found that the foetal tissue displayed radioiodine uptake by 25 days of foetal life and the uptake increased with age. TSH caused a further increase in radioiodine uptake in foetuses of 40 days or older. Incorporation of radioiodine into MIT and DIT was apparent at 25 days and into T3 and T4 by 40 days of foetal life. Addition of TSH increased the proportion of total radioiodine found as DIT and thyroxine in foetuses of 40 days older. This TSH stimulation of radioiodine incorporation increased with age. However, the proportion of radioiodine found as MIT and T3 was not affected before 120 days of foetal life. This was in marked contrast to the adult thyroid where the proportion of radioiodine found as T3 was increased by the addition of TSH. It is concluded that the foetal thyroid can respond to TSH by at least 40 days of foetal life and that this response differs from that seen in the adult.
Forearm insulin uptake in healthy subjects after oral glucose and intravenous glipizide
Authors: Nygren Arne , Lindblad Lars Erik , Sundblad Lars
Published: December 2008

In six healthy subjects fasted overnight two different experiments were carried out on separate days and in random order: A. Oral glucose followed 60 min later by iv glipizide. B. Iv glipizide followed 60 min later by oral glucose. Each experiment was divided into two 60 min periods, and the fractionated insulin uptake by forearm tissue was calculated for each 60 min period. When the fractional insulin uptake values for these four 60 min periods were compared it was found that the uptake of insulin was significantly higher for the 60 min period that was obtained in response to glucose without glipizide pre-treatment, than it was for any of the other 60 min periods. Moreover, in some of the participants the venous insulin concentration occasionally exceeded the corresponding arterial insulin concentration after iv glipizide administration. These findings imply that glipizide may decrease insulin binding to peripheral insulin receptors in healthy individuals.
Influence of lactation on oral glucose tolerance in the puerperium
Authors: Lenz Suzan , Kühl Claus , Hornnes Peter J. , Hagen Claus
Published: December 2008

The influence of endogenous hyperprolactinaemia on oral glucose tolerance in normal women post-partum was studied. An oral glucose tolerance test (OGTT) was performed 8 weeks after delivery in 23 women, 13 of whom were breastfeeding. The lactating women had significantly higher plasma prolactin values before and during the OGTT than the non-lactating women (P < 0.005). Fasting values of serum FSH, LH, progesterone and plasma glucagon were similar in the two groups. The non-lactating women had higher fasting concentrations of serum oestradiol (P < 0.0005), plasma glucose (P < 0.05) and insulin (P < 0.05) than the lactating women. After oral glucose no differences were found between lactating and non-lactating women in changes in plasma glucose, insulin and glucagon concentrations. It is concluded that lactating women 8 weeks post-partum do not have an impaired OGTT compared to non-lactating women despite elevated plasma prolactin levels.
Development and regulation of the prostaglandin F2α receptor in the rat ovary
Authors: Müller Ulrich , Bauknecht Th. , Siebers Jan Willem
Published: December 2008

Ovaries of adult rats specifically bind PGF2α while those of immature animals do not. Induction of luteinization by hCG in juvenile animals, however, results in specific binding of PGF2α It is suggested that luteal cells are the only cell type of the ovary, which is endowed with specific receptors for PGF2α The number of PGF2α binding sites varies during the ovarian cycle. Most free receptors are detectable in early pro-oestrus, least in the oestrus stage. The oscillation of receptors disappears after inhibition of prostaglandin synthesis by indomethacin. Therefore the apparent cyclic variation of prostaglandin receptors must be ascribed to occupancy of the receptors by varying amounts of endogenous prostaglandin F2α.
Glucose metabolism in rat hypothalamus
Authors: Lautala Pentti , Martin Julio M.
Published: December 2008

In vitro glucose oxidation and glucose transport in the rat medial (MH) and lateral (LH) hypothalamic areas was measured. Glucose oxidation was calculated from the conversion of [U-14C]glucose to 14C02 and glucose transport from 14C02 produced from [114C]glucose in the presence of phenazine methosulphate and NaF. Increasing glucose in the medium from 1 him to 20 mm enhanced glucose oxidation two-fold in MH and 40% in LH. Addition of insulin, 100 (iU/ml, to the medium decreased glucose oxidation 30% both in MH and LH at both 4 mm and 20 mm glucose. Fasting did not affect glucose oxidation in either of these hypothalamic areas. Glucose transport was not affected by insulin, but was increased significantly when glucose was raised from 0.25 mm to 1.0 mm. Fasting also increased glucose transport in both hypothalamic areas. In conclusion, extracellular glucose concentration seems to be the major regulator of glucose utilization by the rat hypothalamus. Insulin, rather than increasing, seems to decrease glucose oxidation while having no effect on glucose transport.
Hypothalamic-pituitary function in uraemia
Authors: Cowden E. A. , Ratcliffe W. A. , Ratcliffe J. G. , Kennedy A. C.
Published: December 2008

In a study of 221 patients with progressive uraemia and after successful renal transplantation, all patients had normal levels of plasma 11-hydroxycorticosteroids and sex hormone binding globulin (SHBG). Concentrations of T4 and Ts fell significantly (P < 0.005) with progressive uraemia whilst TSH remained normal. Levels of gonadal steroids also fell significantly (P < 0.0005) and in some patients there was gonadal failure with LH and FSH > 50 U/l; in the remainder, there was a modest increase in LH and minor increase in FSH as renal function deteriorated. Elevated Prl concentrations (P < 0.005) occurred even in moderate chronic renal failure and levels rose with progressive uraemia.

In patients on maintenance haemodialysis, TSH response to thyrotrophin releasing hormone (TRH) was significantly blunted (P < 0.01) at 20 min but showed a late rise at 60 min; basal levels of GH were elevated in 27% and there was a heterogeneous GH response to TRH; LH response to gonadotrophin releasing hormone (GnRH) was normal whilst response of FSH was significantly blunted (P < 0.01). Irrespective of basal Prl level, there was a grossly blunted Prl response to TRH and metoclopramide (MCP) and no suppression of Prl after acute administration of i.-dopa or bromocriptine.

Following successful renal transplantation, endocrine status was entirely normal.

It is concluded that gross biochemical endocrine abnormalities arise with progressive uraemia, which are not ameliorated by maintenance haemodialysis but are abolished by successful transplantation. There is evidence of both hypothalamic and pituitary dysfunction contributing to these anomalies, which may be sensitive indices of non urea and creatinine related uraemic toxicity, and whose significance requires further evaluation.
Effect of inhibin like factors on gonadotrophin release by the mouse pituitary in vitro
Authors: Ramasharma K. , Sairam M. R. , Ranganathan M. R.
Published: December 2008

The release of gonadotrophins by the mouse whole pituitary in vitro was investigated. Whole tissue from 34 day old male mice was highly responsive to synthetic LRH in short incubations at 37°C. About 15% of FSH and 17% of LH were secreted during a 3 h pulse with 3 ng of LRH. Pre-exposure of the mouse pituitary to fractions containing inhibin activity, inhibited the FSH release induced by LRH. Inhibin from bovine and human seminal plasma and porcine follicular fluid preferentially inhibited FSH secretion, while LH secretion was also reduced by inhibin like factors from bovine follicular fluid and testicular extract. The inhibition of FSH and/or LH release was measured by specific radioreceptor assays and could not be due to destruction of either gonadotrophin or LRH. Purified bovine seminal plasma inhibin was effective at very low concentrations in vitro.

The whole incubation system is simple and an estimation of inhibition of bioactive (binding activity) FSH release can be obtained within 24 h.
On the role of dopamine receptors in the central regulation of human TSH
Authors: Delitala G. , Devilla L. , Canessa A. , D'Asta F.
Published: December 2008

The effects of acute administration of haloperidol (4 mg im) and pimozide (4 mg orally) on TSH and Prl secretion were studied in normal and hypothyroid man. The TRH-induced TSH secretion before and after pre-medication with pimozide and domperidone, a peripheral dopamine (DA) blocker, was also evaluated in a group of normal subjects. Haloperidol and pimozide induced a marked increment in serum Prl; mean Prl levels were still significantly elevated 12 h following pimozide administration. A small but significant TSH increase was observed following haloperidol and pimozide in normal as well as hypothyroid subjects. Both domperidone and pimozide significantly enhanced TRH-induced TSH release.

In another experiment 3 women with primary thyroid failure received an infusion of DA (4 (μg/kg/min for 4 h) with and without domperidone administration. TSH and Prl levels were suppressed by DA, but the effect was completely abolished by domperidone.

The results suggest that psychotrophic drugs, such as haloperidol and pimozide, can, like substituted benzamides, stimulate TSH release in man. Since domperidone and DA do not cross the blood-brain-barrier and domperidone significantly enhanced the TSH response to TRH, the data also support the hypothesis that human TSH is regulated by DA at the hypothalamus (median eminence) and/or pituitary level.
Presence of gangliosides in the structure of membrane receptor for thyrotrophin
Authors: Gardas Andrzej , Nauman Janusz
Published: December 2008

Thyroid gangliosides were isolated from bovine thyroid tissue. Neutral lipids and glycolipids were removed by chromatography on a DEAE-cellulose column and residual acidic phospholipids by alkaline degradation.

Thyroid gangliosides were separated by chromatography on a silica acid column into 9 different fractions. Thyroid gangliosides were found to be active in the inhibition of [125I]TSH binding to thyroid plasma membranes and this results from a direct action between thyrotrophin and gangliosides. The most active fraction contained gangliosides with two sialic acids per molecule. Pre-incubation of thyroid plasma membranes for 4 hours at 37°C with gangliosides and removal of the unbound gangliosides increased the [125I]TSH binding to pre-treated membranes by 10–20%.

Anti-ganglioside antibodies obtained by immunisation of rabbits inhibited [125I]TSH binding to thyroid plasma membranes by 60 to 80%. The thyroxine (T4) level in blood serum of immunized animals was significantly decreased after the first immunization and T4 become almost undetectable after the booster injection implying that antibodies against thyroid gangliosides produce severe impairment of thyroid cell function.
The effect of varying iodine content on the proteolytic activity of rat thyroid lysosomes
Authors: Santisteban Pilar , Lamas Luis
Published: December 2008

The possibility that the iodine supply modulates thyroid lysosomal activity was investigated in rats receiving chronic or acute increasing doses of iodide. The lysosomal activity or the various experimental groups was determined by measuring the activity of β-glycerophosphatase and cathepsin D both in thyroid homogenates and in semipurified thyroid lysosomal preparations, and the degradation of labelled thyroglobulin by the various lysosomal fractions. In the chronic experiments β-glycerophosphatase and cathepsin D activities increased with the iodide supply of the animals up to 100 μg I/rat and decreased slightly thereafter. In the acute experiments the activity of these enzymes increased up to 1000 μg I/rat and decreased above 5000 μg I/rat. The proteolytic activity of lysosomal fractions from the various experimental groups towards thyroglobulin decreased slightly with increased iodide supply both in chronic and acute experiments.

The results suggest that thyroid lysosomal activity may participate in the autoregulation of thyroid secretion by inducting synthesis of new enzymes and modulating thyroglobulin degradation.
Insulin, glucagon and somatostatin in the perfused rat pancreas and the effects of HB 699 (4-(2-(5-chloro-2 metoxy-benzamido)-ethyl)-benzoic acid)
Authors: Efendić Suad , Enzmann Franz , Gutniak Mark , Nylén Anita , Zoltobrocki Manfred
Published: December 2008

HB 699 (100 μg/ml), almost identical with the left residue of the sulphonylurea glibenclamide, enhanced basal insulin and somatostatin release from the perfused rat pancreas. The compound also augmented both the early and the late insulin release stimulated by 6.7 mm glucose, while with 16.7 and 33.3 mm glucose only late insulin release was increased. Furthermore, HB699 enhanced both phases of glucose induced somatostatin release irrespective of whether 6.7, 16.7 or 33.3 mM glucose were used. As for glucagon release, HB 699 suppressed basal and arginine stimulated glucagon secretion.

The present findings imply that the sulphonylurea moiety of glibenclamide is not a prerequisite for its stimulatory action on insulin and somatostatin release. It is suggested that the enhanced somatostatin release mediates the inhibitory effect of the compound on glucagon release.
Effect of anaesthesia on serum levels of LH and FSH in man with and without GnRH test
Authors: Bizzarro Antonio , Martino Gennaro Di , lannucci Flavio , Verdoliva Alfredo , Florio Antonino , Guarino Giuseppina , Iacono Giovanni
Published: December 2008

The effect of anaesthesia with atropine and pentobarbital (PB) in three groups of volunteers has been tested. The dose used for the anaesthesia was 20 mg/kg body weight of PB. The experiment was performed with and without stimulation test with GnRH. Anaesthesia was shown to increase serum levels of LH and to increase the response to stimulation with GnRH. Atropine and mental stress seem to have no effect on the hormones. No variation in serum levels of FSH in the anaesthesized volunteers was noted. The data obtained have been statistically controlled.
Gonadotrophin releasing hormone causes a biphasic secretion of luteinizing hormone and follicle stimulating hormone by cultures of rat anterior pituitary cells
Authors: Eddie L. W. , Baker H. W. G. , Higginson R. E. , Hudson B.
Published: December 2008

Primary monolayer cultures of adult male rat anterior pituitary cells secreted both LH and FSH in a biphasic manner when incubated with gonadotrophin releasing hormone (GnRH). The peaks of secretion of LH and FSH were coincident; the first occurred between 15 and 30 min and the second between 1 and 3 h after the addition of GnRH. Approximately 20% of the total amount of gonadotrophins secreted in the 6 h treatment with GnRH was contained in the first peak.

Inhibitors of the secretion of gonadotrophins affected LH and FSH secretion differently. Inhibin suppressed the secretion of FSH to a greater extent than that of LH, whereas testosterone and cycloheximide had a greater effect on LH. Neither phase of secretion of LH or FSH was reduced preferentially by inhibin or testosterone but the greater effect of cycloheximide was on the second phase of secretion.
Estimation of systolic time intervals and timing of arterial sounds in hyperthyroidism during antithyroid medication
Authors: Jerić M. , Banovac K. , Barić Lj. , Sekso M.
Published: December 2008

During antithyroid drug therapy hyperthyroid patients with border-line elevated serum T3 had shortening of pre-ejection period (PEP) and QKd interval (period between the onset of QRS complex and the onset of the Korotkoff arterial sound). There was a significant relationship between PEP and QKd interval with serum T3 concentration in a group of patients under medical therapy; PEP and QKd were normalized later than serum thyroid hormone concentrations in such patients. Propranolol induced a prolongation of PEP and QKd interval in hyperthyroid patients.

PEP and QKd are sensitive measures of metabolic status in thyrotoxic patients during antithyroid treatment.
Tolbutamide, glucose, calcium, and somatostatin secretion
Authors: Hermansen Kjeld
Published: December 2008

We studied the actions of tolbutamide on the release of somatostatin, insulin, and glucagon from the isolated, perfused dog pancreas. Tolbutamide (180 μm) elicited a biphasic response of all three islet hormones in the absence of glucose. In the presence of normal glucose (5.5 mm), 180 μm tolbutamide was again stimulatory, however, now the D cell response appeared uniphasic and the relative increase of somatostatin was lower than in the absence of glucose. At the highest perfusate glucose of 11 mm, no augmentation of the somatostatin output was seen to 180 μm tolbutamide, whereas the B and A cell secretion was still stimulated. In dose-response studies with tolbutamide (1.8–1800 μm) it was found that the D cell threshold to tolbutamide was 18 μm, Furthermore, that maximal D cell secretion was attained in the presence of 180 μm tolbutamide at low glucose (1.4 mm) and of 18 μm tolbutamide at normal glucose (5.5 mm), respectively. The insulin and glucagon responses showed clearcut dose-dependency over the range of tolbutamide doses applied. The B and A cell threshold to tolbutamide was 1.8 μm when the prevailing glucose level was stimulatory for the B and A cell, respectively. The finding that D and B cell responses to tolbutamide were eliminated during calcium deprivation indicates a key role of calcium in the events that proceeds to tolbutamide-mediated somatostatin and insulin release. In conclusion, the primary effect of tolbutamide on the islet cells is to stimulate hormone secretion, however, pertubations in terms of appearance and magnitude of D, B, and A cell responses depend on the balance between the concentrations of tolbutamide and glucose.
Long-term and short-term effects of calcium, verapamil and diazoxide on biosynthesis and release of (pro-)insulin in isolated islets of rat pancreas
Authors: Leinweber K. P. , Schatz H.
Published: December 2008

Glucose-induced release and biosynthesis of insulin can be influenced independently during short-term incubations of isolated pancreatic islets. We studied whether such a dissociation between synthesis and release is still retained after a longer period of islet culture. Media varying in calcium concentration (0, 0.8, 2.5, 5.0 mm), verapamil (8 μm) or diazoxide (100 μg/ml) were used in short-term incubations for 2 h and during 38 h of islet culture at 2 mg/ml glucose.

In the short-term experiments, the increase in calcium concentration caused a stepwise augmentation of insulin release but a gradual decrease in (pro-)insulin synthesis; verapamil and diazoxide markedly diminished insulin secretion, whereas hormone biosynthesis was found unchanged. Culture of islets with calcium omission, verapamil or diazoxide resulted also in a reduced insulin release during the 38 h of cultivation. After culture, insulin release was not different from the controls any more. (Pro-)Insulin biosynthesis, however, was now significantly diminished in islets cultured before with verapamil and diazoxide; following culture in calcium-free medium biosynthesis was also relatively decreased compared to the values obtained in the acute short-term experiments.

It appears from these results that the pharmacological inhibitors of insulin release tested in vitro do no longer influence release and biosynthesis of insulin independently after a longer culture period, in contrast to their short-term effects.
Bioavailability of oestriol
Authors: Englund D. E. , Elamsson K. B. , Johansson E. D. B.
Published: December 2008

A rapid radioimmunoassay, using a specific antiserum against oestriol (Oe3) was developed for the analyses of unconjugated oestriol in post-menopausal women before and after oral administration of oestriol. One ml plasma was extracted once with 10 ml diethyl ether and assayed without further purification. The plasma levels of oestriol in post-menopausal women appear to be below 5 pg/ml. When 10 ml plasma from a pool was assayed 2.9 pg/ml was found. When 1 ml was assayed from individual patients levels between 10–20 pg was found, which was not different from the plasma blank. A rise in plasma oestriol was found already 15 min after oral administration of 6 mg or 12 mg oestriol (Ovesterin®). On the average there was a plasma oestriol peak after 45 min and then a gradual decrease to low levels within 3 to 4 h. It is concluded that oestriol is rapidly absorbed when administered orally. However, the duration of the plasma oestriol elevation is short. Oestriol is rapidly metabolized. The short elevation probably explains the weak oestrogenic effect exerted by oestriol when administered once a day as receptor affinity for oestriol is low.
Cellular growth in several organs of normal and dwarfed Snell mice
Authors: van Buul-Offers Sylvia , Van den Brande Jan Leo , Dumoleijn L. , Feijlbrief M. , van de Klundert P. L. M.
Published: December 2008

The DNA, RNA and protein content of different organs was studied in Snell dwarf mice and compared with unaffected controls at different ages. The following organs were included: liver, kidneys, heart, submandibular salivary glands, spleen and thymus. In normal mice the rapid post-natal growth of all these organs is due to cell division and in the liver, kidneys, heart and submandibular salivary glands to cell enlargement as well.

In dwarf mice weight of most organs studied is comparable with that of 1–2 weeks old normals. The data suggest no differences in cell size between dwarfs and normals in the liver, submandibular salivary glands, spleen and thymus, irrespective of age. In contrast, cell size of the heart and kidneys remains below the normal range and the RNA content is lowered as well. RNA is also low in the submandibular salivary glands and the liver, despite their normal protein content.
Cellular growth in organs of dwarf mice during treatment with growth hormone, thyroxine and plasma fractions containing somatomedin activity
Authors: van Buul-Offers Sylvia , Van den Brande Jan Leo , Dumoleijn L. , Feijlbrief M. , Hoogerbrugge C. M. , van de Klundert P. L. M.
Published: December 2008

DNA, RNA and protein content of the liver, kidneys and spleen were studied in dwarf mice during treatment with human growth hormone (hGH), thyroxine and plasma fractions containing somatomedin activity (SM-P1 and SM-P4).

This investigation has revealed that part of the growth of the liver and all growth of the spleen obtained with the administered preparations, are a consequence of nuclear division. Cell enlargement is not induced in the spleen by either of the preparations used. In the liver a small degree of hypertrophy is obtained with SM-P1. In the kidney both cell number and cell size are stimulated by thyroxine and to a lesser extent by hGH and SM-P1. With regards to the RNA content per cell an increase is obtained with hGH and thyroxine in the liver and in the kidneys also with SM-P1, but not in the spleen.

These data demonstrate that semi-purified SM-preparations, like hGH and thyroxine, might be potent stimuli for the restoration of the impaired nucleic acid metabolism in these organs of the Snell dwarf mouse.
Radioimmunoassay detection of endorphins from long-term culture of human pituitary tumour cells
Authors: Sharp Burt , Melmed Shlomo , Goldberg Ronald , Carlson Harold E. , Refetoff Samuel , Hershman Jerome M.
Published: December 2008

Using a sensitive and precise radioimmunoassay for human β-endorphin, we have demonstrated the sustained secretion of opioid peptides from human pituitary tumour cells. Pituitary tumour tissue obtained from a patient with Nelson's syndrome was maintained in continuous monolayer culture and secreted both β-lipotropin and β-endorphin, with predominance of the latter. This is compatible with the idea that the β-endorphin in normal human serum is secreted as such despite the predominance of β-lipotropin compared with β-endorphin in the anterior pituitary.
Influence of blood removal under ether anaesthesia on the release of prolactin during the oestrous cycle in the rat. Involvement of the ovaries
Authors: Boehm Nelly , Plas-Roser Salomé , Lazarus Christine , Aron Claude
Published: December 2008

The aim of this work was to study the stresslike effects of blood removal unter ether anaesthesia at different stages of the di-oestrus period in 4-day cyclic female rats. Blood removal by heart puncture or laparotomy and bleeding from the abdominal vena cava both under ether anaesthesia were shown to precipitously evoke prolactin release on di-oestrus I morning and on di-oestrus II afternoon. Adrenalectomy did not prevent this effect from occurring on di-oestrus I morning following either procedure of blood removal. Ovariectomy completely suppressed the stress-like effects of ether anaesthesia whereas progesterone appeared capable of restoring prolactin release under these circumstances. No prolactin positive response to ether anaesthesia was observed on di-oestrus II morning, in unoperated controln females.
Release of LH in vitro from anterior pituitary glands of ovariectomized rats by LRH or elevated potassium concentration after pre-treatment with oestradiol benzoate in vivo
Authors: Tijssen A. M. I. , de Koning J. , van Rees G. P.
Published: December 2008

Pituitary glands from ovariectomized rats which had been pre-treated with oestradiol benzoate (OeB) or solvent oil were incubated in Krebs-Ringer bicarbonate buffer with glucose containing either LRH (1000 ng/ml) or a high K+ concentration (50 mM). OeB (7 μg sc) or oil was injected at 2.5 or 6.5 h before the beginning of the incubation experiment or during the three preceding days (three daily injections). Depending upon the period during which the pituitary glands had been exposed to OeB LH release induced by LRH was inhibited (negative effect of OeB) or augmented (positive effect). When the glands were incubated in medium containing high K+, only the negative effect of OeB pre-treatment was seen. It is concluded that that part of LRH-induced LH release which is mimicked by high K+ is involved in the negative effect of OeB, but not in its positive effect.
Susceptibility to proteolysis of thyroglobulin from rats and guinea-pigs treated with excess iodide
Authors: Sinadinović J. , Krainčanič M. , Marinković B. , Jovanović M. , Petrović N. , Liewendahl K.
Published: December 2008

The effect of excess iodide on proteolysis of in vivo 125I-labelled thyroglobulin (Tg) from rats and guinea-pigs was investigated in vitro using preparations of thyroid lysosomes and exogenous proteases (Pronase). Lysosomes were obtained by centrifugation of pig thyroid homogenates. This lysosomal preparation induced maximal proteolysis of Tg at pH 3.6 to 4.6 and was stimulated by KCl. Treatment of rats with excess iodide for up to 28 days had no effect on the proteolysis of Tg by lysosomes or Pronase. Decreased resistance of Tg to proteolysis by lysosomes and pronase was observed in guinea-pigs treated with excess iodide for 3 days, whereas Tg from guinea-pigs treated for longer time periods had increased resistance to proteolysis. This difference in the susceptibility to proteolysis of Tg provides an explanation why long-term administration of excess iodide is goitrogenic in guinea-pigs but not in rats.
Circulating immune complexes in diabetics with severe microangiopathy: evaluation by two different methods
Authors: Andreani Domenico , Mario Umberto Di , Galfo Clara , Ventriglia Luigi , lavicoli Mario
Published: December 2008

An investigation on circulating immune complexes (AgAb) was carried out in 80 diabetics with severe microangiopathy and in 71 diabetics without microvascular lesions.

The duration of the disease, the type of diabetes, the type of treatment and the main localization of microangiopathy (retinopathy and nephropathy) were taken into account. AgAb were detected by two different methods: the solid phase Clq binding test (ClqSP) and the conglutinin binding test (KgBt).

AgAb detected by ClqSP were increased both in prevalence and quantities in diabetics with severe microangiopathy regardless of the duration of the disease and the type of diabetes. Long standing diabetics without microangiopathy had similar prevalence of AgAb as normal controls. The presence of AgAb was not in correlation with the type of treatment and was similar in diabetics with retinopathy and in those with nephropathy. When AgAb were detected by KgBt, they were found with higher prevalence in diabetics than in normal controls but no correlation with microangiopathy was observed. AgAb, detected by KgBt, were higher in long standing type I diabetics.

Since the two methods detect different AgAb it is concluded that AgAb present in diabetics seem to be heterogenous and part of them are related to the presence of microangiopathy.
The effect of ACTH stimulation on plasma steroids in two patients with congenital hypoaldosteronism and in their relatives
Authors: Drop S. L. S. , Frohn-Mulder I. M. E. , Visser H. K. A. , Sippell W. G. , Dörr H. G. , Schöneshöfer M.
Published: December 2008

In two children with isolated congential hyperreninaemic hypoaldosteronism, as well as in their relatives, plasma levels of aldosterone (Aldo), corticosterone (B), deoxycorticosterone (DOC), 18-OH-B and 18-OH-DOC were measured before and after an iv bolus of 0.25 mg Synacthen® (Ciba). A corticosterone methyl oxidase deficiency type II was demonstrated in one child. Her normoreninaemic parents (no consanguinity) had plasma values consistent with heterozygosity. The results in the other child and one asymptomatic sib were compatible with a partial corticosterone methyl oxidase deficiency type I. His parents were consanguine but had normal Aldo levels. Overnight dexamethasone administration did not suppress any of the steroids measured except cortisol, suggesting synthesis of these steroids by the zona glomerulosa.
Effects of ACTH on the zona glomerulosa of sodium-loaded timolol maleate-treated rats: stereology and plasma hormone concentrations
Authors: Nussdorfer Gastone G. , Neri Giulano , Belloni Anna S. , Mazzocchi Giuseppina , Rebuffat Piera , Robba Claudia
Published: December 2008

The effect of chronic ACTH administration on the growth and aldosterone secretion of the zona glomerulosa of sodium-loaded timolol maleate-treated rats was investigated by stereological and radioimmunological techniques. Combined sodium loading and timolol maleate administration induced a significant atrophy of the zona glomerulosa and its cells. The plasma concentration of aldosterone was significantly decreased, while that of corticosterone did not vary. ACTH administration completely reversed zona glomerulosa atrophy, and the plasma concentration of corticosterone was noticeably enhanced, whereas that of aldosterone underwent a further decrease. This data suggests that in the absence of the other adrenoglomerulotrophic factors, ACTH stimulates the growth of the zona glomerulosa, but transforms its parenchymal elements to a functional fasciculata cell type.
Influence of mesonephros on foetal and neonatal rabbit gonads I. Sex-steroid release by the testis in vitro
Authors: Grinsted J. , Byskov A. G. , Christensen I. J. , Jensenius J. C.
Published: December 2008

The experiments were performed to study the influence of mesonephros on gonadal sex hormone release. Foetal and neonatal rabbit testes were cultured for 5 days, with and without their mesonephric tissue. The culture media were harvested every day and analyzed by RIA for the content of testosterone, progesterone and oestradiol. The development of the tissues were evaluated microscopically after culturing.

The results show that between day 20 pc and day 1 pp the mesonephric tissue lowered the amounts of testosterone in co-cultures with testis. This effect disappears when the mesonephric derived cells develop the capacity to synthesize a meiosis inducing substance (MIS). A relationship between decrease of testosterone and secretion of MIS is discussed.

It is concluded that the steroid producing cells of the testis, the Leydig cells, originate or are heavily influenced by mesonephros during early testicular organogenesis.
Influence of mesonephros on foetal and neonatal rabbit gonads
Authors: Grinsted J.
Published: December 2008

To test whether the mesonephros influences the steroid hormone release by the foetal and neonatal ovary, rabbit ovaries were cultured with and without the mesonephros for a period of 5 days. The media were harvested once every day and analyzed by RIA for the content of testosterone, oestradiol and progesterone.

Mesonephros produced progesterone only at day 20 pc. At day 21 and 28 pc significant amounts of all three hormones were produced.

The media of the co-cultures of ovaries with the mesonephros contained on day 23 and 28 pc less testosterone. On day 23 pc less and on day 3 pp more oestradiol was found in the media of the co-cultures. At day 21 pc progesterone release was increased by the mesonephros.

It could be concluded that the mesonephros is able to synthetize steroids and possesses the capacity both to lower and to increase ovarian steroid release in culture. The enhancement of ovarian steroid synthesis in co-cultures with the mesonephros at certain ages might be due either to increased substrate production and/or increased enzymatic activity. The lowering of steroids seen at different ages might be due to mesonephric steroid binding. The mesonephros appeared to influence the male and female rabbits differently at the same ages.
The role of sex hormones in the mechanism of inhibited LH release in female patients with anorexia nervosa
Authors: Baranowska B. , Zgliczyński S.
Published: December 2008

In order to elucidate the mechanism of impaired LH secretion, 60 female patients with anorexia nervosa were investigated. A control group consisted of 14 women of the same age, examined in the follicular phase of the menstrual cycle. The serum LH, FSH, prolactin, TSH, testosterone, dihydrotestosterone, dehydroepiandrosterone, Δ 4-androstenedione, oestrone, oestradiol, oestriol, progesterone, thyroxine, triiodothyronine, reverse T3 and serum sex hormone binding globulin (SHBG) concentrations were measured. The results showed a significant increase in serum dehydroepiandrosterone, testosterone, oestriol and reverse T3 concentrations. However, oestrone, oestradiol, progesterone, SHBG and triiodothyronine levels were significantly lower than those of the control group. The mean serum LH concentration in patients with anorexia nervosa before and after LRH stimulation was significantly lower than that in the control group, but FSH secretion in response to LRH was normal. All hormonal changes in anorexia nervosa disappeared after weight gain during cyproheptadine treatment.

Dramatically increased dehydroepiandrosterone levels suggest that the high testosterone in women with anorexia nervosa is derived from adrenal rather than from gonadal steroids.

There was no correlation between serum testosterone, dehydroepiandrosterone, oestriol and LH concentrations indicating that steroid hormone disturbances do not cause impaired LH release in anorexia nervosa.
Acute suppressive effect of ACTH-induced cortisol secretion on serum prolactin levels in healthy man
Authors: Bratusch-Marrain P. , Vierhapper H. , Waldhäusl W. , Nowotny P.
Published: December 2008

The effect of ACTH on serum prolactin concentrations was studied in 6 healthy women in the follicular phase of the menstrual cycle, in 5 healthy men and in 6 patients (5 males, 1 female) with adrenocortical insufficiency. In healthy women prolactin levels decreased from basal, 14.4 ± 2.1 (SEM) μg/l to 9.4 ± 0.9 μg/l after 30 min and to 8.1 ± 0.7 μg/l after 60 min of iv administration of synthetic ACTH1-24 (0.25 mg). Upon continuous infusion of ACTH1-24 (0.25 mg for 8 h) prolactin fell to 4.4 ± 0.6 μg/l in healthy women and to 4.6 ± 1.5 μg/l (basal: 10.6 ± 1.8 μg/l) in healthy men. In patients with adrenocortical insufficiency prolactin concentrations remained unchanged following an 8 h infusion of ACTH1-24 (before ACTH: 14.5 ± 2.3 μg/l, after ACTH: 16.3 ± 3.1 μg/l). After treatment with dexamethasone (2 mg/day for 3 days) however, prolactin concentrations were suppressed both in healthy women (−52 ± 7%) and men (−25 ± 11%) and in patients with adrenocortical insufficiency (−21 ± 10%). Thus the effect of ACTH on prolactin appeared to be mediated via enhanced cortisol secretion. It is suggested that an acute increase in cortisol levels within the physiological range may modulate prolactin secretion.
Inhibition of thyroidal iodine release by oestrogens in euthyroid subjects
Authors: Zaninovich Angel A. , Boado Rubén , Ulloa Edgardo , Bromage Niall R. , Matty A. J.
Published: December 2008

The effects of oestrogens on the release of thyroxine iodide (T4 I) and non-T4 I by the thyroid gland of 6 normal subjects and 3 thyrotrophin (TSH)-treated patients with hypopituitarism were assessed before, during and after treatment with 25 mg of Dienoestrol (Glaxo Lab.), orally, daily, during 8 days. Each subject received an iv injection of 150 μCi of 125I followed 6 days later by an iv injection of 75 μCi of [131I]T4. Blood samples and collections of urine were obtained every 12 h. From plasma and urinary (U) radioactivity, the ratio U[125I]/ U[131I], U[125I]/PB[125I] and U[131I]/PB[131I] were obtained and served to calculate thyroidal iodine release and non-T4 I secretion by the thyroid gland. T4 I secretion was equivalent to T4 I disposal rate obtained by the semilogarithmic regression line of PB[131I]. In normal subjects, oestrogens decreased T4 I secretion from 491 ± 57 (sd) nmol/day to 451 ± 60 nmol (P < 0.025), while in the same subjects serum TSH increased with oestrogens from 3.3 ± 1.1 to 6.6 ± 2.1 mU/l (P < 0.01). The non-T4 I secretion had a mean of 585 ± 307 nmol/day during control, 324 ± 199 nmol during oestrogens (P < 0.01) and 480 ± 286 nmol after oestrogens (P < 0.05 vs oestrogens). In the TSH-treated patients oestrogens induced non-significant reductions in T4 I and non-T4 I secretion, although total iodine secretion decreased significantly (P < 0.05). The data is consonant with a partial inhibition by oestrogens of thyroid gland release.
Elevated serum thyroxine-binding globulin by X-chromosome transmission
Authors: Penhaligon J. , Wellby M. L.
Published: December 2008

A kindred with a high prevalence of hereditary serum thyroxine-binding globulin (TBG) is described. Seventeen of the 29 members of the kindred have the increased TBG trait as demonstrated by a combination of increased serum total thyroxine (T4) and total triiodothyronine (T3) and decreased T3 resin uptake. In 12 of the 17, the anomaly was confirmed by measuring serum TBG activity as maximum binding capacity of T4. The pattern of increased TBG is consistent with X-linked inheritance. One of the affected members had proven thyrotoxicosis and two others were subjected to sub-total thyroidectomy.
Effects of ethanol and other organic solvents on the kinetic behaviour of purified human placental oestradiol-17β-dehydrogenase
Authors: Lübbert H.
Published: December 2008

The effects of acetone, ethanol, dimethylsulphoxide, glycerol, and propanediol on the formation of reduced coenzyme in the presence of purified human placental oestradiol dehydrogenase were measured fluorometrically at 10 μm oestradiol-17β and 500 μm NAD. Addition of increasing amounts of each solvent except glycerol resulted in an initial increase followed by a decline in rate of the enzyme catalyzed reaction. Glycerol caused a linear decline in rate.

A range (0.1–25%, v/v) of ethanol concentrations was tested for its effect upon the Km and Vmax values for oestradiol, NAD, and NADP. Over this range the Km value for NADP remained nearly constant (0.6–0.8 μm). The Km value for NAD increased rapidly with an upward convex shape of the curve (6.6–25 μm), and the Km value for oestradiol with NAD or NADP as cofactor increased slowly with an upward concave shape (6.7–25 μm). With increasing ethanol concentration, the maximum velocity increased, reaching its highest values at 10 and 20% ethanol for NAD and NADP, respectively, and then declined. At the maximum, Vmax values for NAD and NADP were, respectively, 165 and 200% the values obtained with 0.1% ethanol.
Failure of dexamethasone and ACTH to suppress plasma testosterone in cryptorchid boys
Authors: Facchinetti F. , Bracci R. , Vanni M. G. , Genazzani A. R.
Published: December 2008

Cryptorchid boys show evident alterations in the fine structure of the testes, although they respond in a normal manner to various tests of endocrine function. On the other hand, there is evidence that glucocorticoids suppress plasma testosterone levels, although the mechanism is unknown. Eight control subjects and 8 bilaterally cryptorchid boys, at Pl stage of sexual maturation, were therefore studied by determining the degree of testosterone suppression induced by glucocorticoids. The subjects were submitted to a short dexamethasone (DXM) suppression (1.5 + 0.5 mg at 20.00 and 24.00 h, respectively) and to a short iv ACTH stimulation (1 U/m2 body surface). Basal concentrations of cortisol, androstenedione and testosterone were similar in both groups. Cortisol and androstenedione responded to both DXM suppression and ACTH stimulation in an identical manner in the two groups. DXM lowered the basal levels of testosterone by 46.4 ± 5.8% (mean ± se) in the controls, but only by 6.9 ± 6.6% in the cryptorchid boys (P < 0.001). ACTH only induced a significant decrease in the controls (from 110.9 ± 18.5 to 61.4 ± 10.9 and 72.3 ± 11.8 pg/ml (P < 0.025), after respectively 20 and 30 min), while no significant differences were found in the cryptorchid subjects.

These data indicate that in bilateral cryptorchidism, plasma T is not affected by exogenous (DXM) or endogenous (cortisol) glucocorticoids.