bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of propranolol and carbimazole as adjuncts to iodine-131 therapy of hyperthyroidism
Authors: Aro Antti , Huttunen Jussi K. , Lamberg Bror-Axel , Pelkonen Risto , Ikkala Eero , Kuusisto Arto , Rissanen Viljo , Salmi Jorma , Tervonen Sakari
Published: December 2008

Seventy thyrotoxic patients were treated with carbimazole (36 patients) or propranolol (34 patients) prior to and for 6 weeks after a therapeutic dose of 131I. The therapeutic response was evaluated on the basis of the serum free thyroxine index (FT4I) value and the thyrotoxicosis therapy-index (TTI) of Crooks et al. (1960b). Propranolol alleviated many symptoms and signs (palpitations, hyperkinesia, finger tremor, resting pulse rate) as effectively as carbimazole, whereas others (dyspnoea on effort, tiredness, heat intolerance, sweating, nervousness, bodyweight) were not equally affected. Biochemical euthyroidism was achieved significantly slower in the propranolol group (after 100.6 ± 40.5 days vs. 48.5 ± 24.0 days in the carbimazole group) although the dose of 131I was administered after a mean interval of 22 days from the start of treatment in the propranolol group and after 66 days in the carbimazole group. Between 2 and 6 months after 131I the FT4I and TTI followed a similar course in both treatment groups.

As judged from the TTI scores 2 weeks after the 131I-therapy no evident aggravation of hyperthyroidism occurred in either group of patients. However, one patient in each group showed marked exacerbation of symptoms which was due to inadequate dosage of the drugs. It is concluded that propranolol, given prior to radioactive iodine, is equally effective as carbimazole in preventing aggravation of thyrotoxicosis after the administration of 131I. In the propranolol-treated patients the tests of thyroid function are more reliable during the drug therapy, but the slow development of euthyroidism may be of clinical importance in patients presenting with severe symptoms.
Thyrotrophin binding glycoprotein isolated from bovine thyroid
Authors: Czarnocka B. , Gardas A. , Nauman J.
Published: December 2008

A butanol-water extraction of bovine thyroid plasma membranes was used to solubilize a thyrotrophin receptor. This method was found to solubilize approximately 12% of membrane proteins and 40% of the binding capacity of thyroid membranes for [125I]TSH. Thyrotrophin binding proteins were further purified 10 times over the butanol-water extract and 70 times over the plasma membranes by means of chromatography on DEAE-cellulose and AcA-54 Ultrogel columns. Purified fractions were found to be glycoproteins containing galactose, mannose, galactosamine, glucosamine and sialic acid. A minute amount (6.0 μg per sample) of two glycoprotein fractions obtained after chromatography on AcA-54 Ultrogel caused about 50% inhibition of [125I]-TSH binding to thyroid plasma membranes. This inhibition was due to specific interaction between thyrotrophin and isolated glycoproteins.
Serum levels of oestradiol-17β and luteinizing hormone related to follicular growth as monitored by ultrasound in women with normal menstrual cycles
Authors: Freundl G. , Terinde R. , Distler W. , Baumeister A. , Herberger J. , Kozlowski P.
Published: December 2008

Serum levels of oestradiol-17β (Oe2), luteinizing hormone (LH) and progesterone (P) in 20 healthy women were correlated to the size of the ripening follicle during the follicular phase of normal menstrual cycles. Growing follicles were measured by ultrasound using the full bladder technique. In each individual case a good correlation (r = 0.88) between the Oe2 values and the size of the maturing follicle was found. However, since all women examined ovulated at a different Graafian follicle diameter (range 17 to 26 mm), the corresponding Oe2 values showed quite a large variation (range 0.78 to 2.5 nmol/l).

The cervical score correlated to follicular maturation up to a follicle size of 19 mm (maximal cervical reaction). From then on no further improvement of the cervical parameters could be observed.

We conclude that ultrasound monitoring of follicular growth can be a useful addition to the Oe2 and P measurements in the clinical management of the infertile woman. Bifollicular maturation can be diagnosed early, when the endocrinological data are combined with follicle size. Moreover, a correlation can be made between follicular growth and oestradiol production in the individual cycle.
Characterization of placental luteinizing hormone-relasing factor-like material
Authors: Lee Jau-Nan , Seppälä Markku , Chard Tim
Published: December 2008

High pressure liquid chromatography (HPLC) and radioimmunoassay were employed to characterize luteinizing hormone-releasing factor (LRF)-like material in the human placenta. Methanol extracts of the placenta were washed with acetic acid and chloroform, further purified on coarse octadecylsilane columns, fractionated on HPLC, and tested by radioimmunoassay. In HPLC, placental LRF had the same retention time as synthetic LRF, and such fractions gave an inhibition curve which was parallel to that of synthetic LRF in radioimmunoassav. It is concluded that human placental I.RF is similar or identical to LRF in the central nervous system.
Influence of starvation on testosterone-luteinizing hormone feedback in the rat
Authors: Pirke Karl M. , Spyra Barbara
Published: December 2008

After 5 days of starvation, the body weight of adult male Wistar rats was on the average 34% lower than that of control animals. Luteinizing hormone (LH) and testosterone in plasma were significantly decreased in the starved animals (−95% and −82% on the average). The in vivo response to hCG (10 IU per animal for 3 days) was not diminished in the starved rats. The in vivo stimulation with synthetic LRH (100, 200, 500, 1000 ng/kg body weight iv) caused an increase of LH at all doses. The response however was quantitatively decreased in starved rats. The pituitary content of the LH and the LRH content in the preoptic area and in the hypothalamus were not influenced by starvation; the LRH content, however, was greatly increased in the median eminence (33.2 ± 11.7 versus 15.5 ± 7.1 ng per mg protein).

The feedback was studied by castrating the animals and implanting silastic tubes of various sizes which released testosterone. The plasma levels of testosterone were proportional to the length of the capsules used. LH levels increased greatly (> 90 ng/ml) when testosterone levels were lower than 1.80 ng/ml in the control rats. The straved rats tolerated testosterone levels as low as 1.00 ng/ml plasma before LH was elevated. The LRH content in the median eminence increased in starved and control animals when plasma levels of testosterone dropped below 1.80 ng/ml. These data indicate that the increased sensitivity of the testosterone-LH feedback may be caused by an impaired release of LRH from the median eminence.
Non-specific adsorption of corticotrophin-releasing factor (CRF) to powdered glass
Authors: Yasuda Naoki , Greer Monte A.
Published: December 2008

CRF activity from various sources (rat hypothalamic median eminence and posterior pituitary, bovine hypophyseal stalk, and human peripheral blood) was adsorbed to finely ground glass (Quso, Corning). CRF activity was eluted from the glass with 30% acetone. Up to 85% of the total CRF activity originally present in the crude CRF preparation was adsorbed to Quso or Corning glass; up to 25% of the original total CRF activity was recovered from the glass with 30% acetone. We conclude that CRF is among the hormones adsorbed by glass.
Comparative immunohistochemical studies of γ-melanocyte stimulating hormone (γ-MSH) and adrenocorticotrophic hormone (ACTH) in the bovine and human pituitaries
Authors: Osamura R. Yoshiyuki , Watanabe Keiichi , Tanaka Issei , Nakai Yoshikatsu , Imura Hiroo
Published: December 2008

Comparative immunohistochemical localization of γ-melanocyte stimulating hormone (γ-MSH) and adrenocorticotrophic hormone (ACTH1-24) was studied on bovine and human pituitaries. By the combination of peroxidase labelled antibody method and 'mirror' sections, it was clearly demonstrated that γ-MSH and ACTH were present in the same cells in pars distalis and in pars intermedia or zona intermedia of the bovine and human pituitaries, respectively. Our studies further supported the concept of the production of precursor molecule for these peptides in pars distalis as well as in pars (zona) intermedia.
Effect of thyroid function on serum somatomedin activity
Authors: Marek Josef , Schüllerová Marie , Schreiberová Olga , Límanová Zdeňka
Published: December 2008

To obtain more information about a possible role of somatomedins in mediating the effects of thyroid hormones on the development and function of epiphyseal cartilage, somatomedin activity, measured on the basis of 35S incorporation in embryonic chick cartilage, was studied in thyrotoxic patients before and after treatment with carbimazole or surgery and in a group of patients with primary hypothyroidism. In 29 hyperthyroid patients mean values of somatomedin were 1.29 ± 0.03 sem and differed significantly (P < 0.01) from normals (1.04 ± 0.03). In 15 carbimazole treated patients and in 5 operated patients with thyrotoxicosis somatomedin levels fell from 1.29 ± 0.04 to 1.03 ± 0.04 (P < 0.01) when the patients became euthyroid. Correspondingly, somatomedin levels in 12 untreated hypothyroid patients (0.82 ± 0.04) were significantly less than in normals (P < 0.01) and increased from 0.77 ± 0.09 to 1.14 ± 0.13 (P < 0.05) in 4 patients on replacement therapy. In conclusion: somatomedin levels rise when thyroid hormones are present in excess, and fall when these are deficient. This suggests that thyroid hormones are important regulators of somatomedin levels.
Lipid metabolic studies in oophorectomized women. Effects induced by the addition of norethisterone acetate to two different oestrogens on serum individual phospholipids and serum lecithin fatty acid composition
Authors: Silfverstolpe G. , Johnson P. , Samsioe G. , Svanborg A. , Gustafson A.
Published: December 2008

Norethisterone acetate (NET) was administered to 11 oophorectomized women (mean age 34.5 ± 5.9 years) primed with the 17-C-alkylated ethinyl oestradiol (EOe) and the non-alkylated oestrogen, oestradiol valerate (Oe2V) in separate periods. Blood samples were drawn after 4 weeks without hormonal replacement therapy, after 6 weeks on each oestrogen and after 6 weeks on each oestrogen-progestogen combination. Routine liver function tests were carried out, assessment of individual phosholipids i.e. cephalin, lecithin, lysolecithin and sphingomyelin was done after thin layer chromatography. The relative fatty acid composition of serum and high density lipoprotein lecithin and serum cholesterol ester was determined by gas liquid chromatography.

The redistribution of serum individual phospholipids (increase in lecithin and decrease in lysolecithin) induced by both oestrogens was reversed by the addition of NET. This lecithin-lysolecithin shift seen after NET administration could depend on a stimulation of the hepatic lipase with its phospholipase Al-activity. The 17-C-alkylated EOe, but not the non-alkylated Oe2V, caused an increase in palmitic and a decrease in stearic acid in the 1-position of serum lecithin. When NET (like EOe, 17-C-alkylated) was added to EOe, this palmitic-stearic acid shift was further accentuated, and it also appeared when NET was added to Oe2V. It is suggested that the shift in 1-position fatty acids of serum lecithin induced by EOe and NET is a non-hormonal 'drug-effect' linked to their 17-C-alkylation and liver toxicity. The reduction in arachidonic acid of serum lecithin and serum cholesterol ester seen after NET administration is interpreted as an anti-oestrogenic effect which could be mediated by a decreased transformation of linoleic to arachidonic acid in the liver.
Clomiphene stimulation test in men with idiopathic hypospermatogenesis
Authors: Johnsen Svend G.
Published: December 2008

A standardized clomiphene stimulation test with assay of serum FSH, LH, testosterone and oestradiol and urinary androsterone + aetiocholanolone, dehydroepiandrosterone and total oestrogens was applied to 23 men with idiopathic hypospermatogenesis as compared with 12 normal controls. In the patients the percentual rise of LH was increased and the percentual rises of testosterone and oestradiol decreased as compared with controls. The study thus showed that abnormalities in the testicular steroid producing apparatus exist in hypospermatogenesis and could be the cause of the spermatogenetic failure. It was further showed that the reserve capacity of the testicular steroid production is highly limited in contrast to the large reserve capacity of gonadotrophin production in the hypophysis.
Serum prolactin and thyrotrophin responses to thyrotrophin-releasing hormone at different times of the day in normal women
Authors: Pérez-López F. R. , Gómez G. , Abós M. D.
Published: December 2008

In order to determine whether or not the pituitary responsiveness to thyrotrophin-releasing hormone (TRH) changes during the nyctohemeral cycle, 10 healthy regularly cycling women were given 200 μg of TRH at 02.00 h, 10.00 h and 18.00 h with at least a 32 h interval between each test. Serum prolactin (Prl) and thyrotrophin (TSH) in 7 of the 10 women were measured serially before and after TRH administration. The mean basal Prl levels were significantly higher (P < 0.01) at 02.00 h than at 10.00 h and 18.00 h. The mean basal TSH levels were higher, although not significantly, at 02.00 h than at 10.00 h and 18.00 h. Although a higher TSH release occurred at 02.00 h than at 10.00 h and 18.00 h, the mean serum TSH and Prl peak responses to TRH were statistically similar in the three groups of tests. The integrated changes scores, calculated as the difference between the average post-TRH hormonal release and the average baseline levels, although higher in the 18.00 h test for Prl and the 02.00 h test for TSH, were not statistically different among the three tests.
Iliac crest bone mass and remodelling in acromegaly
Authors: Halse Johan , Melsen Flemming , Mosekilde Leif
Published: December 2008

Iliac crest bone biopsies from 18 patients with active acromegaly, of whom 11 had received tetracycline double-labelling, were evaluated by quantitative histomorphometry and compared with age- and sex-matched normal controls. A significant increase (P < 0.01) was found in both cortical (175%) and trabecular (130%) bone mass. In trabecular bone, resorption surfaces and active (tetracycline-labelled) and total formation surfaces were increased (P < 0.05 and P < 0.01, respectively) causing an enhanced bone turn-over at tissue level (P < 0.01). The increased trabecular bone mass indicates a positive net balance per remodelling cycle and, therefore, larger than normal bone remodelling units, which in part may explain the increased bone turn-over at tissue level. The activity of the osteoblasts active in mineralization (the appositional rate) was increased (P < 0.01) and positively related to the fasting serum growth hormone levels (Rs = 0.69, P < 0.05). The average activity of active and inactive osteoblasts (bone formation rate at basic metabolic unit (BMU) level) was insignificantly increased. The proportion of active (tetracycline labelled) to non-active formation surfaces was normal. The bone changes were unrelated to serum levels and urinary excretions of calcium and phosphorus or to renal excretion of total and non-dialyzable hydroxyproline or cAMP.
HLA-A, -B, -C and -DR antigens in patients with Graves' disease and their correlation with signs and clinical course
Authors: Dahlberg P. A. , Holmlund G. , Karlsson F. A. , Säfwenberg J.
Published: December 2008

Among 78 consecutive patients with Graves' disease, an increased frequency of HLA-B8 and HLA-DR3 antigens was found. The relative risk for Graves' disease among individuals with these HLA antigens was calculated as 4.4 and 3.9, respectively. Thus, genes promoting the development of Graves' disease are clearly associated to the B8 and DR3 haplotypes. In groups of patients with different clinical expressions of the disease, such as thyroid hormone levels, autoantibodies and relapse rates, the frequency of B8 and DR3 antigens was found to be similar. Consequently, factors influencing the clinical expression and the course of the disease do not have a stronger association to these antigens.
Effects of graded doses of triiodothyronine on TSH synthesis and secretion rates in hypothyroid rats
Authors: Lemarchand-Béraud Th. , Berthier C.
Published: December 2008

The effects of a graded low dose of T3 on plasma TSH, anterior pituitary TSH content (AP-TSH) and on TSH synthesis and secretion rates, were studied in adult male rats previously treated for 7 days with 0.01% prophylthiouracil (PTU). Pituitary TSH content, plasma T3, T4 and TSH levels were measured by RIA at 0, 6, 12, 24 h after the injection of T3 ranging from 0.1 to 0.75 μg/100 g b.w. Saline treated normal rats served as control. The 7-day PTU treated rats displayed low but still detectable thyroid hormone plasma levels; high plasma TSH levels were observed, but with no further increase after TRH injection as the AP-TSH content was depleted. Injections of T3 increased plasma T3 in proportion with the dose given. Plasma T4 remained low and there was no significant decrease in plasma TSH until doses of 0.2 μg/100 g b.w. T3 was given. Then the transient TSH depression was dose-dependent from 0.2 to 0.75 μg/100 g b.w. The AP-TSH content increased regularly from 0.2 μg/T3 onwards, overlapping the transient inhibition of TSH secretion resulting in a 3-fold increase in the AP-TSH content, suggesting a positive action of T3 on TSH synthesis. In addition, TSH response to TRH was observed at every time studied after T3 injection. Then, the different groups were injected with [125I]rTSH in order to estimate metabolic clearance rates, TSH secretion and synthesis rates.

The half-life of [125I]rTSH (22 min) and its metabolism clearance rates (16 ± 0.4 ml/h/100 g b.w.) were found similar in all groups. Whereas the TSH secretion rates was highly reduced in the normal rats receiving 0.3 μg T3 (156 ± 9 vs 408 ± 22 μg/24 h in normal rats), the PTU group displayed a 3-fold increased secretion rate (1222 ± 44 μg/24 h) which was not modified by the injection of 0.1–0.2 μg T3 and decreased to 868 and 472 μg/24 h with 0.3 μg and 0.75 μg T3, respectively. TSH synthesis rates were found highly increased in the PTU group (1222 ± 44 μg/d vs 408 ± 22 μg/d in normal rats) and was neither increased nor reduced in the 7-day PTU rats receiving 0.1–0.3 μg T3 but a slight reduction was observed only in the 0.75 μg T3 group.

These data show that 0.1–0.2 μg/100 g b.w. T3 changed neither TSH secretion nor its synthesis rates while 0.3 μg more or less a replacement dose inhibited TSH secretion without changing TSH synthesis rates, resulting in a AP-TSH replenishment. Therefore, no direct positive effect of low doses of T3 on TSH synthesis could be demonstrated over 24 h while higher doses are capable of inhibiting first secretion and then synthesis of TSH.
The influence of vitamin D intake on serum calcium in tuberculosis
Authors: Gwinup Grant , Randazzo Guy , Elias Alan
Published: December 2008

We report the first prospective controlled study designed to determine the effect of vitamin D ingestion on serum calcium concentration in patients with tuberculosis. Every patient admitted to the tuberculosis ward over a 6 month period, who was free of any condition which might influence serum calcium concentration, was randomly assigned to one of two groups. The diet of the first group was substituted with ergocalciferol 5000 units daily. The diet of the second group was not supplemented. In addition, the second group was randomly subdivided into two subgroups. The first subgroup received a diet unrestricted in vitamin D. The second subgroup received a diet containing less than 50 units of vitamin D. Serum calcium was determined at weekly intervals. In contradistinction to the results of a previously reported retrospective study, there was no significant difference between the group receiving supplemental vitamin D and the control group at any time during the entire period of study. Furthermore, there was no significant difference between the subgroup of patients receiving normal dietary vitamin D and the sungroup maintained on the diet restricted in vitamin D.
Serum levels of testosterone, cortisol, prolactin and bioactive luteinizing hormone in adult male rhesus monkeys following cage-restraint or anaesthetizing with ketamine hydrochloride
Authors: Puri C. P. , Puri V. , Kumar T. C. Anand
Published: December 2008

The present studies were carried out to characterize and compare the acute effects of cage-restraint or administration of a mild anaesthetic on serum levels of testosterone (T) cortisol (C), prolactin (Prl) and bioactive luteinizing hormone (LH) in adult male rhesus monkeys. Serum T levels declined progressively while C levels increased in the 3 sequential blood samples obtained at 20 min intervals from restrained monkeys. Prl and LH levels in the serum remained unaltered. Following single or multiple injections of ketamine hydrochloride (10 mg/kg) serum T levels did not decline progressively as seen in the blood samples obtained from the cage-restrained, conscious monkeys. Serum C and Prl levels showed a progressive rise following anaesthetization. LH levels were not affected by the anaesthetic. The findings reported here are of pertinent relevance to the evaluation of acute effects of any experimental procedure aimed at altering circulating levels of the hormones studied.
A sensitive bioassay for luteinizing hormone-like activity applied to systemic plasmas of foetal rats
Authors: Picon Régine , Habert René
Published: December 2008

A sensitive bioassay for plasma LH-like activity has been developed by utilization of the testosterone response of foetal rat testes to gonadotrophic stimulation in vitro. The volume of plasma required for the assay and the target organ make the method suitable for bioassays of circulating LH-like activity in foetal rat plasma. When applied to foetal plasmas, the method has shown that castration performed on day 19 of gestation induced 24 h later an increase in the LH-like activity of the plasma and that decapitation under the same conditions led to a decrease in this activity in male foetuses.
Treatment of maternal hyperthyroidism with antithyroid agents and changes in thyrotrophin and thyroxine in the newborn
Authors: Lamberg B.-A. , Ikonen E. , Teramo K. , Wägar G. , Österlund K. , Mäkinen T. , Pekonen F.
Published: December 2008

Eleven pregnant women with concomitant hyperthyroidism were treated with antithyroid drugs. At monthly intervals serum thyroxine (T4) and triiodothyronine (T3) were measured with radioimmunoassay, the Sephadex uptake of radioactive triiodothyronine (T3U) determined and the free T4 and T3 indices calculated (FT4I, FT3I). TSH-binding inhibiting immunoglobulins (TBII) were determined by the radiomembrane assay. Serum TSH and T4 were measured at delivery from cord blood and/or from the newborn infants some days after birth.

Serum TSH was significantly elevated in one infant. There was an inadequate post-partal rise in serum T4 concentration in this child and in another who showed only a marginal elevation of TSH. The mothers of these infants were given carbimazole in doses of 30 and 25 mg/day, respectively, at the time of delivery. No significant changes were seen in other infants, the daily doses being 20 mg of carbimazole or less. There was no clinical indication of hypo- or hyperthyroidism in any of the newborn.

The TBII were positive in most patients and there was a trend of normalization during treatment. No relationship between the dose of antithyroid drug and the level of TBII could be seen. During treatment the dose was adjusted according to the FT3I values. This seems to be an adequate laboratory test for this purpose.
Effect of epinephrine and 5-hydroxytryptamine on in vitro thyroid iodine organification
Authors: Masini-Repiso Ana María , Coleoni Aldo Héctor
Published: December 2008

The effect of epinephrine (E) and 5-hydroxytryptamine (5-HT) on some elements involved in thyroid iodine organification was studied using a bovine thyroid subcellular fraction sedimented at 30 000 g. 131I-incorporation into particulate proteins and into tyrosine was increased by 10−3 m and 10−5 m E and 5-HT. This effect was inhibited by 6-n-propyl-2-thiouracil and by catalase.

In the presence of these amines the activity of NADPH-cytochrome c reductase was not modified. Both E and 5-HT were able to generate H2O2 when added to the particulate fraction as measured by the oxidation of o-dianisidine. H2O2 generation and [131I]iodotyrosine formation were inhibited by pargyline, a monoamine oxidase (MAO) inhibitor. Tyramine, a specific substrate for thyroid MAO, produced H2O2 and increased [131I]iodotyrosine formation. This effect was higher when compared to the effect elicited by E or 5-HT. The stimulatory effects of tyramine were blocked by pargyline. The action of tyramine on H2O2 generation and [131I]iodotyrosine formation was diminished when E or 5-HT were incorporated to the system.

From these results it is suggested that E and 5-HT serving as MAO substrates would generate H2O2 and in this way increase the thyroid iodine organification. On the other hand, these amines would be able to reduce the increased H2O2 generation induced by tyramine and thus decrease the iodination process. These findings could explain the stimulatory or inhibitory effects of biogenic amines on thyroid function which are dependent on the previous thyroid activity.
The disappearance of l-thyroxine and triiodothyronine from plasma and red and white skeletal muscle after administration of one sc dose of l-thyroxine to hyperthyroid and euthyroid rats
Authors: Janssen J. W. , de Lange-Berkhout I. W. L. , van Hardeveld C. , Kassenaar A. A. H.
Published: December 2008

Rats were made hyperthyroid by repeated sc injections of l-thyroxine (T4) in a two-week period. At several time-points after the last injection, the triiodothyronine (T3) and T4 concentrations in plasma and red and white skeletal muscle were determined by a radioimmunoassay. This was done to investigate the relationship between the change in thyroid-hormone concentration in plasma and muscle and to see whether this change was similar in both muscle types. The results show that:

1. Information about the T3 and T4 concentrations in the muscles of the hyperthyroid rats can only be obtained by direct measurement in the muscles and cannot be gathered from the plasma-T3 concentration at any time-point or from below-normal plasma-T4 concentrations.

2. In hyperthyroid rats T4 and T3 are cleared more rapidly from the plasma than from the skeletal muscle.

3. A proportionally higher T3 concentration is present in the red compared with the white skeletal muscle of hyperthyroid rats.
Gonadotrophin release by gonadotrophs incubated with gonadotrophin-releasing hormone is independent of intracellular cAMP accumulation
Authors: Benoist L. , Le Dafniet M. , Rotsztejn W. H. , Besson J. , Duval j.
Published: December 2008

Rat pituitary cells were dispersed with trypsin and separated by sedimentation at unit gravity. The distributions of prolactin (Prl), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were determined, and two enriched cell populations (mammotrophs and gonadotrophs) were subsequently cultured. During a 4 h incubation, gonadotrophin-releasing hormone (GnRH) stimulated the release of LH and of FSH by both the unfractionated population and the enriched gonadotrophs; the magnitude of this stimulation increased with the length of the pre-culture periods, and the amount of LH released into the medium correlated strongly with the amount of FSH, whatever the length of the pre-culture period. The cellular cAMP content was also enhanced during the 4 h incubation, but no correlation was found between the hormone release and the cAMP accumulation. Furthermore, during the first 30 min of incubation with GnRH there was no increase of cellular cAMP, whatever cell population used.

We conclude that the gonadotrophin release was independent of the cAMP accumulation observed in pituitary cells several hours after stimulation by GnRH; consequently, the late increase in the nucleotide is suggested to be a non-specific secondary process.
Prolactin content in rat pituitary gland. RIA of prolactin after different extraction procedures
Authors: Haggi E. , Aoki A.
Published: December 2008

The prolactin content of rat pituitary varies considerably when determined by RIA, due to incomplete solubilization of prolactin secretory granules with standard procedures for tissue homogenization and centrifugation. Freezing and thawing, Triton X-100 and ultrasonic treatments increased the yield of prolactin significantly but electron microscopy of pellets revealed numerous unmodified secretory granules. Addition of 2.5 m urea produced complete extraction of tissue prolactin confirmed by RIA of supernatants and electron microscopy of pellets.
Micromethod of human thyrocyte cultures for detection of thyroid-stimulating antibodies and thyrotrophin
Authors: Stöckle G. , Wahl R. , Seif F.J.
Published: December 2008

The activation of adenylate cyclase of human thyrocytes in primary cell cultures and the release of cAMP into the medium are used to detect thyrotrophin (TSH) and thyroid-stimulating antibodies (TSAb) in sera of patients with Graves' disease. Tissue digestion and cell dispersion are performed using a neutral protease of Bacillus polymyxa (Dipase II), which harvests more vital thyrocytes than does trypsin. The cells show an enhanced response to stimulation. The efficeincy of the cell preparation and cultivation is increased by using microtest plates instead of culture flasks. By this minimization only 0.6–1.8 × 106 cells are needed to evalute a single sample. Cyclic AMP concentrations are measured directly in the supernatant culture medium by a competitive protein binding assay with charcoal separation. The minimal detectable dose of bTSH is about 10 μU/ml. With increasing doses of bTSH cAMP concentrations rise to a peak at about 50 to 100 mU/ml, beyond which there is a gradual decrease of cAMP indicating negative cooperativity in the activating mechanisms. The 'long-acting thyroid stimulator' effect of TSAb is reflected by a protracted increase of cAMP to its maximal value. All 41 sera of hyperthyroid patients with Graves' disease were TSAb-positive, whereas sera of patients with toxic nodular goitre and of euthyroid controls were TSAb-negative.
Plasma prolactin and gonadotrophins in anorexia nervosa and amenorrhoea due to weight loss
Authors: Skrabanek P. , Devlin J. , McDonald D. , Powell D.
Published: December 2008

The role of prolactin in anorexia nervosa is controversial and both hyperprolactinaemia and normoprolactinaemia were reported in patients with anorexia nervosa. We have measured immunoreactive prolactin by radioimmunoassay in plasma samples from 14 consecutive patients with anorexia nervosa and found normoprolactinaemia in 13 patients and a borderline elevation of plasma prolactin in one patient. The mean plasma prolactin level in anorexia nervosa patients did not differ from an age-matched control gorup of patients with amenorrhoea due to simple weight loss. While we were unable to confirm reports on the common occurrence of hyperprolactinaemia in anorexia nervosa, the absence of hyperprolactinaemia suggests a different mechanism of amenorrhoea in patients with anorexia nervosa and due to simple dieting from that in idiopathic secondary amenorrhoea in which the frequency of hyperprolactinaemia is about 30%. The mean plasma follicle-stimulating hormone was abnormally low both in patients with anorexia nervosa and simple weight loss, while the mean plasma luteinizing hormone was depressed only in patients with anorexia nervosa. This difference is compatible with a more profound hypothalamic disorder in anorexia nervosa, which is not solely dependent on the weight loss, than in amenorrhoea due to simple dieting.
Properties of human thyroidal and extrathyroidal TSH receptors
Authors: Trokoudes Krinos M. , Michelsen Harold , Kidd Arthur , Row Vas V. , Volpé Robert
Published: December 2008

The presence of high affinity receptor sites for thyroid-stimulating hormone (TSH) in the human is not limited to the thyroid gland. In this report, the properties of thyroidal and extrathyroidal TSH binding have been explored through the effect of various agents (TSI of Graves' disease, propranolol, hCG, N-acetylneuraminic acid, ACTH, insulin and L-thyroxine) on the receptors.

Statistically significant inhibition of [125I]TSH binding occurred with all immunoglobulin preparations (TSI) of Graves' disease on thyroid cell membrane receptors. Thirty-three per cent of the same immunoglobulins showed significant inhibition of [125I]TSH binding when testicular cell membranes were used, while there was no such inhibition when renal cell membranes were utilized. D or L-propranolol at least doubled the [125I]TSH initial binding (Bo) to the thyroid membranes but had no effect on the testicular or fat cell binding. Human chorionic gonadotrophin (hCG) at concentrations of 400 USP units per 350 μl totally inhibited the [125I]TSH from binding to testicular membranes but not to thryroid or fat cell membranes. Conversely, the binding of [125I]hCG to human testicular membrane was inhibited by both stable hCG and TSH, but with human thyroid membrane, only TSH could inhibit binding of [125I]hCG. These data suggest that the TSH receptors in extrathyroidal tissues may not be identical to TSH receptors within the thyroid. TSH binding to thyroidal tissue was significantly suppressed by N-acetylneuraminic acid, was increased by D and L-propranolol and was unaffected by ACTH and insulin. L-thyroxine had a dose-related suppressive effect on the TSH binding, commencing at 50 μg/ml. While these effects were observed in vitro, it is possible that some of the above agents may also interfere with thyroid gland function in vivo. They suggest further that a number of interactions may take place at the TSH binding sites which could alter TSH binding and/or function.
Paradoxical effect of perchlorate on thyroidal weight, glucose 6-phosphate dehydrogenase and polyamines in methylthiouracil-treated rats
Authors: Matsuzaki S. , Suzuki M.
Published: December 2008

The effect of sodium perchlorate (NaClO4) on the methylthiouracil-induced increase in the activity of thyroid glucose 6-phosphate dehydrogenase (G6PDH), ornithine decarboxylase (ODC) and polyamine contents was studied in the rat. The G6PDH activity was increased nearly three-fold by methylthiouracil (MTU) but not by ClO4- at 7 days of treatment. Perchlorate lowered the MTU-induced enzyme activity to nearly the control level, without changing circulating thyrotrophin (TSH). The anion had no inhibitory effect on G6PDH activity in vitro. The possibility that an inhibitor specific for G6PDH was generated in ClO4- treated rat thyroids was excluded.

The activity of ODC was greatly increased by both ClO4- and MTU, the increase being significant as early as on the second day of treatment. Perchlorate had no inhibitory effect on MTU-induced ODC activity in vivo but decreased total contents of spermidine and spermine in the thyroid, without affecting the concentration (nmoles/ g wet weight) of the polyamines. These results suggest that ClO4- acts directly on the thyroid to suppress specifically the stimulatory effect of TSH on G6PDH activity and possibly on polyamine accumulation.
Plasma aldosterone response to acute stimulation in panhypopituitarism
Authors: Birkhäuser M. , Rionde A. M. , Gaillard R. , Mantero F. , Vallotton M. B.
Published: December 2008

The influence of acute stimulation by ACTH, upright posture and angiotensin II on plasma aldosterone levels was assessed in human panhypopituitarism.

While stimulation by ACTH in hypopituitary patients induced a plasma aldosterone increase similar to that observed in healthy controls, stimulation by upright posture or by infusion of angiotensin II resulted in a lower plasma aldosterone response than in controls in most of the patients.

These results suggest that the presence of an anterior pituitary hormone, most likely ACTH, directly or indirectly exerts a permissive action on aldosterone secretion in man.
Inhibitory effect of potassium on blood pressure in DOCA salt hypertension in rats
Authors: Suzuki Hiromichi , Kondo Kazuoki , Saruta Takao
Published: December 2008

The present study was performed to assess the influence of potassium on blood pressure in deoxycorticosterone (DOCA) salt hypertensive rats. The effects of potassium administration on the systolic blood pressure, fluid intake, urine volume, excretion of sodium and potassium, serum sodium and potassium, plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were investigated both during the first 2 weeks of development of DOCA salt hypertension and during the next 2 weeks of established DOCA salt hypertension. Potassium administration prevented the development of DOCA salt hypertension and reduced the blood pressure in established DOCA salt hypertension. Fluid intake, urine volume, and excretion of sodium and potassium appeared to be markedly increased in rats treated with potassium. The levels of serum sodium and potassium were unchanged by potassium loading. Both the PRA and PAC which were suppressed in DOCA salt hypertensive rats, were reversed in rats treated by potassium loading. It is suggested that the elevation of blood pressure may be prevented and the increased blood pressure reduced mainly by the diuresis and natriuresis caused by potassium loading.
Effects of prolonged ACTH treatment on adrenal steroidogenesis and blood pressure in rats
Authors: Vazir H. , Whitehouse B.J. , Vinson G. P. , McCredie E.
Published: December 2008

The effects of long-term (8–16 days) treatment of rats with synthetic 1–24 ACTH (100 μg/day) on adrenocortical function and blood pressure have been investigated. After 16 days, treated animals had considerably enlarged adrenals, a reduced body weight and systolic blood pressures of 169 ± 3 mmHg compared with 117 ± 4 mmHg in untreated controls. Corticosterone and 18-hydroxydeoxycorticosterone (18-OH-DOC) production in vitro from endogenous precursors was increased 3–4-fold in capsules and 1.5-fold in inner zones, whereas production of aldosterone and 18-hydroxycorticosterone was reduced. Similar increases in corticosterone and 18-OH-DOC production by capsules and inner zones were found with 12 days' treatment, during which blood pressure increased to a constant level after 8 days. Secretion of 18-OH-DOC and corticosterone by the left adrenal gland in anaesthetised rats was significantly higher in the ACTH treated group while the secretion of aldosterone was more than 80% lower. The aldosterone response of dispersed capsule cells to stimulation by potassium (8.4 mmol/l) and ACTH (10−8 mol/l) was lost following ACTH treatment. The responses of inner zone and capsule dispersed cell preparations to ACTH (10−8 mol/l) were reduced compared with controls. Restriction of the rats' sodium intake (to less than 20 μmol/day) during ACTH treatment did not prevent the decrease in aldosterone production in vitro, nor the increase in blood pressure. Overall chronic ACTH treatment resulted in a marked inhibition of aldosterone production and response to stimulation coupled with an increase in corticosterone and 18-OH-DOC production. The results are consistent with the hypothesis that ACTH induces functional transformation of the glomerulosa cell to a fasciculata-like cell. It appears that the hypertension in ACTH treated rats should be related to the increased secretion of corticosterone and 18-OH-DOC, and that aldosterone and 18-hydroxycorticosterone are not involved.
Effect of oestradiol-17ß on the metabolism of noradrenaline in brain slices of ovariectomized rats
Authors: Köster G. , Breuer H.
Published: December 2008

Ovariectomized rats received a single injection of 10 μg oestradiol-17β 3-benzoate; 90 min or 19 h after injection, slices of various brain areas were prepared and incubated with tritiated noradrenaline for 30 min. Methylated and non-methylated metabolites of tritiated noradrenaline were determined after chromatographic separation. Nineteen h after administration of oestradiol-17β 3-benzoate, the formation of normetanephrine, 3-methoxy 4-hydroxy phenylglycol and 3-methoxy 4-hydroxy mandelic acid was decreased (P < 0.05) in hypothalamic tissue, whereas that of 3,4-dihydroxy mandelic acid was increased (P < 0.001). In thalamus tissue a decrease of normetanephrine (P < 0.05) and an increase of 3,4-dihydroxy mandelic acid (P < 0.01) were also observed. No conclusive results were obtained with hypophyseal tissue. The present findings suggest that oestrogens reduce the methylation of noradrenaline, probably through a competitive inhibition of the catechol-O-methyl-transferase by 2-hydroxylated oestrogens.
Somatomedin activity measured as sulphation factor in culture media from normal human liver and connective tissues explants. Effects of human growth hormone
Authors: Schimpff R. M. , Donnadieu M. , Gautier M. , Polini G. , Repellin A. M.
Published: December 2008

Normal human explants from liver and from connective tissues (aponeurosis or skin) incubated in vitro released sulphation activity measurable in chick embryo cartilage. Addition of human Growth Hormone (hGH) at physiological levels (10 ng/ml) increased the sulphation activity after 6 hours incubation time. Higher doses failed to increase the sulphation activity produced by connective tissues and decreased the sulphation activity produced by the liver.
Sensitivity of insulin secretion to feedback inhibition by hyperinsulinaemia
Authors: DeFronzo Ralph A. , Binder Christian , Wahren John , Felig Philip , Ferrannini Eleuterio , Faber Ole K.
Published: December 2008

The ability of insulin to inhibit its own secretion was examined in 15 normal subjects given an intravenous infusion of insulin in a dose of 0.25, 0.50, 1.0, 5.0 or 10.0 mU/kg/min for two hours. Arterial plasma insulin concentration achieved during the infusion segregated into three levels of hyperinsulinaemia: 35 ± 1 (mean ± sem), 87 ± 15 and 828 ± 210 μU/ml. Plasma glucose concentration was kept constant at the basal level by a variable glucose infusion. Fasting C-peptide (0.29 ± 0.02 pmol/ml) fell significantly in all subjects during hyperinsulinaemia and reached a concentration of 0.19 ± 0.03 pmol/ml at 60 min and 0.14 ± 0.03 at 120 min after the start of the insulin infusion. The C-peptide response was not related to the infusion dose nor to the steady state plasma insulin concentration.

It is concluded that (a) basal insulin secretion as evaluated from C-peptide measurements is inhibited by small (24 ± 3 μU/ml) physiological elevations in plasma insulin concentration independent of changes in plasma glucose, and (b) supraphysiological or even pharmacological elevations in plasma insulin do not result in a further decrease in endogenous insulin secretion above that achieved with mild hyperinsulinaemia.
Mineralocorticoid and metabolic response to metyrapone in normotensive children and children with dexamethasone-suppressible and primary hyperaldosteronism
Authors: Sonino Nicoletta , Levine Lenore S. , New Maria I.
Published: December 2008

The effect of 5 to 9 days of metyrapone administration (400 mg/m2 every 4 h) on aldosterone, deoxycorticosterone, plasma renin activity, electrolyte balance, and blood pressure was investigated in 2 normotensive siblings (one of whom showed limited ACTH reserve), in 3 patients with hypertension and dexamethasone-suppressible hyperaldosteronism, and in a hypertensive patient with primary hyperaldosteronism due to bilateral adrenal hyperplasia.

Results:

1. Plasma and urinary aldosterone levels were steadily suppressed by metyrapone in all cases, except in the oldest patient studied who had dexamethasonesuppressible hyperaldosteronism and in whom, after a few days, aldosterone gradually rose to normal levels. 2. Mild mineralocorticoid effect occurred only in the normal subject. In all other patients there was no apparent mineralocorticoid effect despite deoxycorticosterone hypersecretion. 3. There was no significant change in blood pressure with metyrapone administration in any patient.
Isolated growth hormone deficiency, ovarian dysgenesis and Turner stigmata with normal chromosomal complement
Authors: McNeil Larry W. , Daniel James F. , Russell Marcia H. , Rabin David
Published: December 2008

An 18 year old white female presented with short stature and amenorrhoea. Her height was 135 cm, weight 46.6 kg; she had a broad neck, a high arched palate, short fifth metacarpals bilaterally, short third, fourth and fifth metatarsals bilaterally and minimal breast development. Although the clinical picture strongly suggested Turner's syndrome, investigations revealed: (a) normal female 46,XX chromosomal pattern on analyses of skin, lymphocytes and ovarian tissue; (b) undetectable serum growth hormone levels; (c) pre-pubertal oestradiol-17β levels; (d) only very occasional primordial follicles on ovarian biopsy with a thickened capsule; and (e) basal LH and FSH levels of 6.8 and 9.6 mIU/ml which rose after LRH injection to 90 and 26 mIU/ml, respectively. The patient has the unusual combination of growth hormone deficiency, gonadal dysgenesis and Turner stigmata with a normal chromosomal complement.
Luteal blood flow and plasma steroids in rats with corpora lutea of different ages
Authors: Damber Jan-Erik , Janson Per Olof , Axén Claes , Selstam Gunnar , Cederblad Åke , Ahrén Kurt
Published: December 2008

Ovarian and luteal blood flow rates were measured at different stages of luteal development in anaesthetized rats using 15 ± 5 μm radioactive microspheres. Ovulations were induced by injection of 8 IU of PMSG at 28 days of age. Steroid concentrations in peripheral plasma were determined using radioimmunoassays. The highest luteal blood flow was found in the youngest corpora lutea and decreased gradually with luteal age. Luteal flow on days 13 and 14 was significantly lower than that of days 2,4, and 6. Ovarian stromal blood flow remained unchanged throughout the lifespan of the corpus luteum. Peripheral progesterone concentrations rose significantly on days 4, 6, and 8 with a maximum on day 8, as compared to day 2, and fell significantly after day 8. The levels of 20α-OH-progesterone increased sharply on day 10, indicating functional luteolysis. The progesterone levels fell significantly between day 8 and 10 without a concomitant significant decline in luteal blood flow. Since a fall in progesterone production seems to precede a drop in luteal blood flow, the initiation of luteolysis does not appear to be caused by a vascular mechanism.
Possible circadian periodicity of foetal prolactin secretion late in gestation
Authors: Yaginuma Tsutomu
Published: December 2008

Prolactin levels were determined in samples of umbilical venous blood at vaginal delivery after 38–42 weeks of uncomplicated gestation. The mean level of prolactin for all samples was 328.4 ± 7.4 (se) ng/ml. The levels did not vary significantly during these weeks of gestation, nor correlate with the duration of labour. The means of levels combined every 2 h varied significantly throughout the 24 h period with a maximum value of 460.3 ± 85.1 ng/ml at 2–4 a.m. and a minimum value of 241.4 ± 27.2 ng/ml at 6–8 a.m. and remained relatively constant between 2–4 and 10–12 p.m. These results suggest that a circadian periodicity may exist in the secretion of prolactin by the human foetus, and that this is not affected by labour and delivery.