bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stage-specific expression of the FSH receptor gene in the prepubertal and adult rat seminiferous epithelium
Authors: Rannikko A , Penttilä T-L , Zhang F-P , Toppari J , Parvinen M , Huhtaniemi I 
Published: December 2004

Abstract
Stage-specific expression of the FSH receptor (FSHR) gene in the rat seminiferous epithelium was studied. Using transillumination-assisted microdissection for sample preparation and Northern hybridization for analysis of total RNA, we first reassessed the stage specificity of the FSHR gene expression in the adult rat testis. Sixfold higher FSHR mRNA levels were found in stages XIII–I compared with stage VI of the seminiferous epithelial cycle, which had the lowest signal level (P<0·01). The other stages had intermediate signal levels. In situ hybridization showed distribution of grains which confirmed the data obtained by Northern analysis. Prepubertal stage-specific FSHR gene expression was studied using in situ hybridization. Stage specificity could first be demonstrated at the age of 16 days when the average grain counts in stages I–IV were threefold higher than in stages VI–VII (P<0·01). The present data are in agreement with earlier findings on stage-specific FSH binding and FSHR gene expression using both microdissected and stage-synchronized seminiferous tubules. The onset of stage-specific FSHR gene expression is concomitant with maturation of the Sertoli cell population and completion of the first generation of spermatocytes. This supports the hypothesis that spermatogonia and spermatocytes may be involved in the regulation of FSHR gene expression.
Journal of Endocrinology (1996) 151, 29–35
Regulation of intestinal cholecystokinin gene expression by glucocorticoids
Authors: Ratineau C , Roche C , Chuzel F , Cordier-Bussat M , Blanc M , Bernard C , Cuber J-C , Chayvialle J-A 
Published: December 2004

Abstract
The effect of glucocorticoids on the expression of intestinal cholecystokinin (CCK) was investigated both in vivo and in cell culture systems. In vivo, 2-day administration of methylprednisolone to adult male rats induced a decrease in CCK-like immunoreactivity (CCK-LI) and CCK mRNA levels in mucosal extracts. In two CCK-producing cell lines, RIN 1056E and STC-1 of pancreatic and intestinal origin respectively, dexamethasone induced dose-dependent decreases in both CCK-LI and steady-state CCK mRNA levels. The decrease in CCK mRNA was totally prevented by incubation of cells with an excess of RU 38486, a competitive inhibitor for the binding of glucocorticoids to their receptor. Actinomycin D, used to prevent RNA synthesis, did not modify CCK mRNA stability in dexamethasone-pretreated cells as compared with cells not exposed to dexamethasone. When cells were first incubated with actinomycin D, subsequent addition of dexamethasone left the steady-state CCK mRNA levels unaltered in both cell lines. Nuclear run-on assays performed in RIN 1056E cells showed that glucocorticoids decreased the rate of transcription of the CCK gene. In addition, cycloheximide, used to prevent protein synthesis, abolished the inhibitory effects of dexamethasone on steady-state CCK mRNA levels. These results demonstrate that glucocorticoids down-regulate CCK gene expression in the rat intestinal mucosa and in two CCK-producing cell lines. The effect is blocked by a glucocorticoid receptor antagonist. Inhibition of CCK gene expression may result from a decrease in the transcription rate, and probably involves one or several steps that depend on protein synthesis.
Journal of Endocrinology (1996) 151, 137–145
Interleukin-1β inhibits rat thyroid cell function in vivo and in vitro by an NO-independent mechanism and induces hypothyroidism and accelerated thyroiditis in diabetes-prone BB rats
Authors: Reimers J I , Rasmussen A K , Karlsen A E , Bjerre U , Liang H , Morin O , Andersen H U , Mandrup-Poulsen T , Burger A G , Feldt-Rasmussen U , Nerup J 
Published: December 2004

Abstract
Interleukin-1β has been implicated as a pathogenic factor in the development of autoimmune thyroiditis. When given for 5 days to normal non-diabetes-prone Wistar Kyoto rats, it decreased plasma concentrations of total tri-iodothyronine and thyroxine and increased plasma TSH. These effects were not prevented by co-injection of nitroarginine methyl ester or aminoguanidine, inhibitors of NO synthases. Exposure to interleukin-1β dose-dependently reduced iodine uptake in FRTL-5 cells, but had no effect on thyroglobulin secretion. Nitrite was not detected in the FRTL-5 cell culture media after exposure to interleukin-1β. However, reverse transcription PCR analysis of mRNA isolated from interleukin-1β-exposed FRTL-5 cells revealed a transitory expression of the inducible NO synthase, which was markedly lower than inducible NO synthase induction in interleukin-1β-exposed isolated rat islets of Langerhans. Co-incubation with the NO synthase inhibitor NG-monomethylarginine did not ameliorate the effect of interleukin-1β on FRTL-5 cell iodine uptake. Furthermore, we demonstrate that daily injections of interleukin-1β for 13 weeks aggravated spontaneous thyroiditis and induced severe hypothyroidism in non-diabetic diabetes-prone BB rats. The data suggest that NO does not mediate interleukin-1β-induced inhibition of rat thyroid function in vivo or in vitro in FRTL-5 cells, and the induction of hypothyroidism by interleukin-1β in diabetes-prone BB rats is speculated to be due to exacerbation of recruitment and activation of intrathyroidal mononuclear cells.
Journal of Endocrinology (1996) 151, 147–157
Transcription initiation of the rat insulin-like growth factor-I gene in hepatocyte primary culture
Authors: Krishna A Y , Pao C-I , Thulé P M , Villafuerte B C , Phillips L S 
Published: December 2004

Abstract
Transcription initiation in the insulin-like growth factor-I (IGF-I) gene is complex, involving multiple sites in two exons. While most transcripts are initiated in exon 1 in vivo, critical regulatory mechanisms are difficult to assess in intact animals. To examine the impact of insulin and growth hormone (GH) under more controlled conditions, we have studied the utilization of different exon 1 and exon 2 transcription-initiation sites in normal rat hepatocytes in primary culture. Normal rat hepatocytes were cultured for 48 h in serum-free medium, with insulin at 10−6 or 10−11 m, and with or without human GH 200 ng/ml. Relative abundance of IGF-I transcripts was evaluated by the RNase-protection assay, using a probe which permitted identification of initiation in exon 1 (site 1 (−380 bp from the 3′ end of exon 1), site 2 (−343 bp), site 3 (−242 bp), sites 1 and 2 spliced, and site 4 (−32 bp)), as well as in exon 2. After normalization of signal intensity to adjust for differences in length of protected probe, the utilization of initiation sites in vitro was remarkably similar to that in vivo: 1, 14, 6, 23, 19 and 37% for sites 1, 2, 3, 1 and 2 spliced, 4 and exon 2 respectively in the cultured hepatocytes, compared with 1, 12, 8, 21, 18 and 40% for these sites in normal liver. Insulin alone increased transcripts initiated from exon 1, site 2 by over 3 times, and both sites 1 and 2 spliced and exon 2 transcripts by about 5 times. GH alone had similar effects, producing a 4–5 times increase in transcripts from these initiation sites. Addition of both insulin and GH had additive effects, increasing transcripts from exon 1, sites 2, 3 and 4 by 4–6 times, and from exon 1, sites 1 and 2 spliced, and exon 2 by over 8 times. Of the total IGF-I mRNA transcripts, 37% were initiated from sites 2 and/or sites 1 and 2 spliced, and 37% from exon 2. Analysis of the relative contribution of individual initiation sites revealed hormone-induced increases which were statistically significant only for exon 2, in the presence of insulin alone and in combination with GH.
In conclusion, in cultured hepatocytes, insulin or GH alone produced a coordinated increase in all exon 1 transcripts, and the effect of the combination of insulin and GH was additive for these transcripts. Exon 2 appeared to be more sensitive to insulin alone, and to GH in the presence of insulin, than exon 1. Since utilization of initiation sites in hepatocytes mimics that found in liver, this in vitro system should be useful for examining underlying transcriptional regulatory mechanisms.
Journal of Endocrinology (1996) 151, 215–223
Plasma levels of chromogranin A are directly proportional to tumour burden in neuroblastoma
Authors: Wassberg E , Stridsberg M , Christofferson R 
Published: December 2004

Abstract
A novel animal experimental model involving the human, poorly differentiated, and adrenergic neuroblastoma cell line SH-SY5Y xenotransplanted to subcutaneous tissue of 13 nude rats (WAG rnu/rnu) was used to investigate the usefulness of six proposed neuroblastoma markers. It was shown that the plasma concentrations of human chromogranin A (CgA) as measured by RIA were directly proportional to tumour volume (r=0·83, P<0·001). To rule out possible liberation of CgA by tumour cell lysis, the CgA degradation product pancreastatin was also measured in plasma by a specific RIA, but was not detectable. Plasma neurone-specific enolase (NSE) was elevated in tumour-bearing animals (P<0·01), but did not correlate with tumour volume (r=0·49, P>0·05). Urine homovanillic acid (HVA), detected by HPLC, was elevated in tumour-bearing animals (P<0·01), but did not correlate with tumour volume (r=−0·32, P>0·05). Urine vanillyl mandelic acid was not detectable. Urine dopamine was found in low concentrations that did not correlate with tumour volume. In summary, although plasma NSE and urinary HVA were elevated in tumour-bearing animals only plasma CgA correlated with tumour burden. This makes CgA a promising biochemical marker for neuroblastomas.
Journal of Endocrinology (1996) 151, 225–230
Differential regulation of granulocyte-macrophage colony-stimulating factor mRNA and protein expression in human thyrocytes and thyroid-derived fibroblasts by interleukin-1α and tumour necrosis factor-α
Authors: Aust G , Hofmann A , Laue S , Ode-Hakim S , Scherbaum W A 
Published: December 2004

Abstract
In this study, we provide the first report on the production of granulocyte-macrophage colony-stimulating factor (GM-CSF) by human thyroid epithelial cells. Primary cultures of highly purified thyrocytes and thyroid-derived fibroblasts (n=3) and three thyroid anaplastic and one largely papillary carcinoma cell lines were exposed to different potent GM-CSF stimulators, employing interleukin 1α (Il-1α) and tumour necrosis factor-α (TNF-α). Cytokine mRNA levels were monitored by semiquantitative reverse transcriptase-PCR including an internal heterologous competitor fragment after 3, 6 and 18 h of culture. Culture supernatants were assayed for GM-CSF using a highly sensitive ELISA (detection limit ≤ 0·5 pg/ml) after 24 h.
Basal GM-CSF mRNA expression was higher in fibroblasts and SW 1736 cells compared with thyrocytes, C 634, 8505 C and HTh 74 cells. GM-CSF was spontaneously secreted by fibroblasts (means ± s.e.m.; 43 ± 15 pg/ml), SW 1736 (59 ± 4 pg/ml), HTh 74 (34 ± 4 pg/ml) and C 643 cells (12 ± 1 pg/ml) but not by thyrocytes and 8505 C cells. Treatment with Il-1α (10 U/ml) resulted in a marked increase of GM-CSF mRNA within 3 h and an increase or induction of protein expression in thyrocyte (2350 ± 214 pg/ml), fibroblast (5242 ± 1400 pg/ml), SW 1736 (20016 ± 280 pg/ml) and C 643 cultures (1285 ± 79 pg/ml). Stimulation with TNF-α (10 U/ml) yielded divergent results. No significant increase of GM-CSF mRNA or protein expression was found in thyrocytes although TNF-α receptor expression in these cells is well documented. Stimulation with TNF-α resulted in an increased GM-CSF production in fibroblasts (361 ± 14 pg/ml), HTh 74 (148 ± 51 pg/ml) and SW 1736 cultures (235 ± 43 pg/ml). TSH (10 mU/ml) did not stimulate GM-CSF secretion in thyrocytes and HTh 74 cells, both expressing the TSH receptor. Phorbol 12-myristate 13-acetate (10 ng/ml) enhanced GM-CSF mRNA and protein levels in all cell types investigated.
Our data suggest that both thyrocytes and fibroblasts synthesize GM-CSF in response to Il-1α, but only fibroblasts respond to TNF-α with a significant increase in GM-CSF. Anaplastic thyroid carcinomas are potential GM-CSF producers.
Journal of Endocrinology (1996) 151, 277–285
Investigation of the effects of antisense oligodeoxynucleotides to islet amyloid polypeptide mRNA on insulin release, content and expression
Authors: Kulkarni R N , Smith D M , Ghatei M A , Jones P M , Bloom S R 
Published: December 2004

Abstract
We have investigated the effects of antisense oligodeoxynucleotides (oligos) to islet amyloid polypeptide (IAPP) mRNA on the expression and secretion of IAPP and insulin, in the clonal β-cell line HIT-T15. Phosphorothioate-modified oligos were cytotoxic compared with phosphodiester (D)-oligos. Of the nine oligos tested using a lipofection reagent, 03, a 30-mer D-oligo complementary to a sequence downstream of the IAPP initiation codon, showed a significant dose-dependent suppression of IAPP mRNA, with a 42% decrease at 7·5 μm, compared with a scrambled (MS03) control oligo (n=3, P<0·01). A subsequent 89% suppression of IAPP release was observed in the 4-h period following antisense treatment (1·78 ± 0·13 (MS03) vs 0·19 ± 0·14 (03) pmol/106 cells per 240 min, n=7, P<0·01). A significant increase in insulin mRNA (100 ± 10% (MS03) vs 124 ± 8% (03), n=3, P<0·05) and insulin content (13·0 ± 0·9 (MS03) vs 17·4 ± 1·4 (03) pmol/106 cells, n=7, P=0·028) was observed following treatment with 03 at 7·5 μm. 08, a 20-mer D-oligo directed to a region of IAPP mRNA further downstream than 03, also showed a decrease in IAPP mRNA and peptide release and an increase in insulin content. No significant changes were observed in the expression and release of the unrelated β-cell peptide, neuropeptide Y. We thus show a suppression of synthesis and release of IAPP in HIT-T15 cells using antisense oligos. The associated increase in insulin mRNA and content in these cells after treatment with IAPP antisense oligos is in accord with an inhibitor action of IAPP on insulin availability.
Journal of Endocrinology (1996) 151, 341–348
Repartitioning of maternal muscle protein towards the foetus induced by a polyclonal antiserum to rat GH
Authors: Palmer R M , Thom A , Flint D J 
Published: December 2004

Abstract
Growth and protein accretion were studied in maternal muscle and liver and in foetuses of rats on day 20 of pregnancy. In young rats, weighing 120 g at mating, muscle mass and protein content of three hind-limb muscles, soleus, plantaris and gastrocnemius, increased on average by 7% compared with non-pregnant controls although the rate of muscle protein synthesis was decreased. In mature rats, rates of muscle protein synthesis were also reduced on day 20 of pregnancy but no change in muscle mass was observed. Rates of liver protein synthesis and accretion were increased in the pregnant animals; the effect was larger in the young pregnant rat. Administration of an antibody to rat GH (anti-rGH) for 10 days to young pregnant rats reversed the effect on the same three maternal muscles and resulted in a 9–11% lower muscle mass and protein content, compared with control pregnant animals. In both young and mature dams serum IGF-I concentrations were halved on day 20 of pregnancy, a further small reduction was observed in response to anti-rGH. No significant change in serum insulin or corticosterone levels was observed. Anti-rGH treatment also reduced food intake but foetal weight at 20 days was significantly increased (14%). The effects on maternal muscle were not the result of loss of appetite associated with anti-GH administration as, in rats pair-fed to the intake of the anti-rGH group, maternal muscle and foetal weights were the same as in animals with food available ad libitum. The data suggest that the GH/IGF axis is involved in the partitioning of nutrients between the dam and the foetus.
Journal of Endocrinology (1996) 151, 395–400
The effect of epidermal growth factor on circulating levels of IGF and IGF-binding proteins in adult Goettingen minipigs
Authors: Vinter-Jensen L , Orloff Juhl C , Frystyk J , Dajani E Z , Oksbjerg N , Flyvbjerg A 
Published: December 2004

Abstract
It has recently been demonstrated that epidermal growth factor (EGF) administration to neonatal rodents causes growth retardation with concomitant reductions in circulation levels of IGF-I. We describe the effects of systemic EGF administration for 4 weeks on circulating levels of IGF-I and IGF-binding proteins (IGFBPs) and on thyroid hormones (tri-iodothyronine, T3; thyroxine, T4) in sexually mature pigs. Goettingen minipigs of either sex were treated with placebo (n=5) or EGF (30 μg/kg per day, n=6) s.c. for 4 weeks (in relation to an oesophageal sclerotherapy regimen). Blood samples were taken under anaesthesia before and after 1, 2, 3 and 4 weeks of treatment. Circulating levels of IGF-I, insulin, glucose, T3 and T4 were analysed every week and IGFBPs every second week. IGF-I was not reduced significantly after 1 week but significantly reduced after 2 and 3 weeks of EGF treatment. A similar decline was observed for the major IGFBP, IGFBP-3, which was reduced after 2 and 4 weeks. IGFBP-1, IGFBP-2 and IGFBP-4 increased throughout the treatment period (all significantly at week 4). EGF treatment induced increased circulating T3 after 2, 3 and 4 weeks of EGF treatment. In conclusion, we report that EGF treatment for 4 weeks in Goettingen minipigs reduces circulating IGF-I and IGFBP-3, increases circulating IGFBP-1, IGFBP-2 and IGFBP-4, and induces a slight hyperthyroidism as judged from increased circulating levels of T3.
Journal of Endocrinology (1996) 151, 401–407
Thyroxine effect on intestinal Cl−/HCO3− exchange in hypo- and hyperthyroid rats
Authors: Tenore A , Fasano A , Gasparini N , Sandomenico M L , Ferrara A , Di Carlo A , Guandalini S 
Published: December 2004

Abstract
Changes in transepithelial water and electrolyte transport as causative or contributing factors of the diarrhoea and constipation found associated with changes in thyroid physiology were studied. Albino Wistar rats were pharmacologically made either hypothyroid or hyperthyroid. After sacrifice, the small intestine was mounted in Ussing chambers in order to measure in vitro ion net fluxes under short-circuit conditions. Hypothyroid animals showed an increase in intestinal transit time, Cl− absorption (mainly due to an increment in its mucosal to serosal component) and residual ion flux (which is believed to represent HCO3− secretion) when compared with euthyroid animals. The hyperthyroid animals showed a decrease in Cl− mucosal to serosal transport. Furthermore, a significant correlation was found between serum l-thyroxine (T4) levels and both net Cl− transport (r= −0·74, P<0·00001) and residual ion flux (r= −0·55, P<0·005).
These results indicate that the effect of T4 is firstly to inhibit Cl−/HCO3− anion exchange thereby influencing transepithelial flux transport and secondly to affect intestinal motility. Such inhibition was not found when T4 was acutely added to rat ileum, suggesting that the effect on electrolyte transport probably requires protein synthesis. In conclusion, the phenomenon observed in vitro could explain the clinical manifestations of constipation and diarrhoea in hypo- and hyper-thyroidism respectively.
Journal of Endocrinology (1996) 151, 431–437
Hepatocyte growth factor/scatter factor and its receptor c-met: localisation and expression in the human placenta throughout pregnancy
Authors: Clark D E , Smith S K , Sharkey A M , Sowter H M , Charnock-Jones D S 
Published: December 2004

Abstract
Hepatocyte growth factor (HGF), also known as scatter factor, acts via the c-met receptor resulting in pronounced effects on certain epithelial cells. We hypothesised that HGF would be important in placental development where the trophoblast represents a specialised barrier of epithelial origin. In this paper we examine the expression and production of HGF and its receptor in the human placenta throughout pregnancy. In addition, RT-PCR was undertaken on human embryos to ascertain whether preimplantation embryonic or trophoblast cells were under the influence of this growth factor. In samples from the first trimester of pregnancy in situ hybridisation with a c-met antisense probe detected message expression in villous cytotrophoblast and in decidual glands but not in extravillous trophoblast. Some c-met expression was detected in cytotrophoblast from the second trimester placentae; this declined to negligible levels by term. Staining with an anti c-met antibody largely confirmed these findings but found relatively strong staining of cytotrophoblast at term. HGF was confined to the villous core throughout pregnancy when examined by both in situ hybridisation and immunohistochemistry. Trophoblast was consistently negative for HGF. Pre-implantation embryos examined by RT-PCR were negative for both c-met and HGF mRNA. These results indicate that the HGF may exert an important influence on cytotrophoblast throughout the process of placental formation and growth.
Journal of Endocrinology (1996) 151, 459–467
Effect of lactation on insulin signal transduction in sheep adipose tissue and skeletal muscle
Authors: Wilson L A , Mills S E , Finley E , Kilgour E , Buttery P J , Vernon R G 
Published: December 2004

Abstract
The molecular basis of the insulin resistance of adipocytes and skeletal muscle during lactation has been investigated in sheep. The number of insulin receptors per adipocyte or per unit membrane protein for skeletal muscle is unchanged by lactation. The ability of insulin to stimulate autophosphorylation of its β-subunit was enhanced in adipocytes but not in skeletal muscle during lactation. This increased autophosphorylation was due, at least in part, to enhanced tyrosine phosphorylation and was found when both solubilised, immunoprecipitated insulin receptors and intact adipocytes were incubated with insulin. The ability of the insulin receptor kinase to phosphorylate other proteins did not appear to be altered by lactation; this was shown with lectin-purified insulin receptors using the artificial substrate, polyglutamyl tyrosine, and in intact adipocytes. Lactation had no effect on the ability of insulin to activate two key downstream kinases, mitogenactivated protein kinase and phosphatidyl inositol-3-kinase in adipocytes. The study thus shows that the insulin resistance of lactation in sheep is due to changes downstream of the receptor in both adipocytes and skeletal muscle.
Journal of Endocrinology (1996) 151, 469–480