AIMTo know the effect of cysteamine (CS) on the plasma levels of somatostatin (SS) and some metabolic hormones in adult geese.

METHODSFourteen adult crossbred geese (Chuan white x Tai lake) fitted with chronic wing vein cannulas were used in this study to evaluate the effect of CS on SS, TSH, T3 and T4 levels. The experiment was consisted of control and treated phase. The diet was added CS at dosage of 100 mg/kg bw on the first day of the treated phase. The blood samples were collected from the cannulas and analyzed by radioimmunoassay.

RESULTSThe plasma SS concentration was (1.87 +/- 0.10) microg/L in control phase. Whereas SS concentrations on day 1, 3, 5, 7 of treated phase were decreased markedly (P < 0.05 or P < 0.01). Thereafter it was rose on the seventh day, however it was still lower than that of control. The thyroid stimulating hormone (TSH) content (2.45 +/- 0.31 mIU/L) was significantly decreased by 21.63% (P < 0.01) on day 1, and 18.37% (P > 0.05) on day 3 and day 5. Comparing with control phase (5.41 +/- 0.98 microg/L), T4 contents were elevated by 60.26% (P < 0.01), 43.25% (P < 0.01), 37.15% (P < 0.01) and 16. 82% (P < 0.01) respectively on day 1, 3, 5, 7. T3 level was (1.05 +/- 0.06) microg/L in control phase, whereas the levels was significantly increased by 36.19% (P < 0.01) on day 3. Also, the insulin concentration was higher than that of control (4.43 +/- 0.41 mU/ L) by 18.28% (P < 0.05) on the day 5.

CONCLUSIONThese results indicate that CS can decrease the plasma SS and TSH levels, whereas increase the levels of T4, T3 and insulin, therefore change metabolism, improve the nutrition transform and accelerate the growth in geese.

Animals ; Cysteamine ; pharmacology ; Diet ; Geese ; Insulin ; blood ; Somatostatin ; blood ; Thyrotropin ; blood ; Thyroxine ; blood ; Triiodothyronine ; blood

OBJECTIVETo explore the effects of retinol acid (RA) and triiodothyronine (T3) on alleviating the impairment of cognitive function by sleep deprivation (SD).

METHODSMale Wistar rats were divided into 4 groups: control group (C group), sleep deprivation group (SD group), sleep deprivation + RA group (SD + RA group) and sleep deprivation + T3 group (SD + T3 group). Open field test (OFT) was used to observe the nervous behavior of the rats after SD and electrophysiological brain stereotactic method was used to test long-term potentiation (LTP) in dentate gyrus (DG) of the rats. Ng protein expression was determined by Western blot.

RESULTSCompared with the SD group, the number of crossing in OFT, the changes of amplitude of population spike (PS) and the expression of Ng protein in hippocampus were higher significantly in the SD + RA and SD + T3 groups. All of these had not significant difference comparing with the C group.

CONCLUSIONRA and T3 may alleviate the restrain state of neural system after SD by augmenting the expression of Ng protein in hippocampus.

Animals ; Cognition ; drug effects ; Dentate Gyrus ; metabolism ; Long-Term Potentiation ; Male ; Neurogranin ; metabolism ; Rats ; Rats, Wistar ; Sleep Deprivation ; metabolism ; psychology ; Triiodothyronine ; pharmacology ; Vitamin A ; pharmacology

OBJECTIVETo investigate the role of Bcl-2 in the cytoprotective effect of thyroid hormone against hippocampal cell apoptosis in rats with chronic cerebral ischemia.

METHODSFifty adult male SD rats were randomized into sham-operated group, 2-vessel occlusion (2VO) group and triiodothyronine (T3) treatment group. At 7 and 14 days after the operation, the tissue structure of the CA1 region was observed with Nissl staining, and TUNEL staining was used to determine the apoptosis index (AI) in the dentate gyrus; Western blotting was performed to detect the expression level of Bcl-2 in the hippocampus.

RESULTSIn the 2VO group, the CA1 region of the hippocampus showed obvious structural damages with reduced number of neurons, and these changes were significantly improved in T3 treatment group. At 7 days after the operation, no significant difference was found in AI between the sham-operated group (17.714∓2.553), 2VO group (20.868∓2.090) and T3 group (20.365∓1.055) (P=0.060); the expression level of Bcl-2 was higher in T3 group than in 2VO group. On day 14, AI was 66.532∓3.249 in 2VO group, significantly higher than that in T3 treatment group (56.153∓4.556, P=0.001); Bcl-2 expression was the highest in T3 group and the lowest in 2VO group.

CONCLUSIONThyroid hormone can reduce cell apoptosis in the hippocampus of rats with chronic cerebral ischemia possibly by up-regulating the expression of Bcl-2.

Animals ; Apoptosis ; drug effects ; Brain Ischemia ; pathology ; CA1 Region, Hippocampal ; cytology ; pathology ; Male ; Neurons ; cytology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Rats ; Rats, Sprague-Dawley ; Triiodothyronine ; pharmacology

OBJECTIVETo study the effects of excess iodine intake on neurogranin expression in cerebrum of filial mice and the intervention of selenium.

METHODSSixty BALB/c mice were divided randomly into four groups with different drinking water: control group (tap water, NC), excess iodine group (3000 microg/L I, EL +), supplementing selenium group (200 microg/L Se, Se +) and the excess iodine plus selenium (3000 microg/L + I 200 microg/L Se, EI + Se +) group. The mice were mated at the end of the fourth month. Serum T4 and T3 were determined on postnatal day 14 and 28. The expression level of neurogranin in filial cerebrum was measured by immunohistochemistry and Western blot.

RESULTSSerum T4 level in EI (68.78 +/- 11.10 nmol/ L) + was lower significantly than that in NC (100.85 +/- 11.47 nmol/ L) and EI + Se + (93.15 +/- 12.10 nmol/ L) on postnatal day 14. Western blot analysis showed that the relative level of neurogranin in EI + (0.621 +/- 0.041) was lower than that in NC (0.841 +/- 0.039) and EI + Se + (0.781 +/- 0.029) on postnatal day 14 (P < 0.05). No significant difference in serum T4 and neurogranin level between four groups on postnatal day 28.

CONCLUSIONExcess iodine intake might change the expression of neurogranin in filial cerebrum and the selenium supplementation might alleviate it.

Animals ; Female ; Iodine ; adverse effects ; Male ; Mice ; Mice, Inbred BALB C ; Neurogranin ; biosynthesis ; Selenium ; pharmacology ; Telencephalon ; metabolism ; Thyroxine ; blood ; Triiodothyronine ; blood

OBJECTIVETo study the interaction between insulin-like growth factor binding protein-3 (IGFBP-3) and thyroid hormone receptor α1 (TRα1) and the modulatory effect of IGFBP-3 on transcription of the thyroid hormone responsive gene.

METHODSThe interaction between IGFBP-3 and TRα1 was detected with glutathione-S-transferase pull-down method, co-immunoprecipitation, fluorescence resonance energy transfer test. The cellular distribution of these two proteins was observed by confocal laser scanning microscopy. The effect of IGFBP-3 on the growth hormone promoter activity stimulated by triiodothyronine (T3) was determined by dual-luciferase reporter assay.

RESULTSIGFBP-3 interacted with TRα1 both in vivo and in vitro. IGFBP-3 and TRα1 were shown to co-localize in the nucleus of HEK-293 cells. The overexpressed IGFBP-3 inhibited the growth hormone promoter activity stimulated by T3 (P<0.01).

CONCLUSIONSIGFBP-3 interacts with TRα1 and inhibits T3 responsive gene transcription. This finding further confirms the insulin-like growth factor-independent role of IGFBP-3 in the nucleus.

HEK293 Cells ; Humans ; Insulin-Like Growth Factor Binding Protein 3 ; metabolism ; Promoter Regions, Genetic ; Thyroid Hormone Receptors alpha ; metabolism ; Thyroid Hormones ; genetics ; metabolism ; Transcription, Genetic ; Triiodothyronine ; pharmacology

AIMTo determine whether 7-oxo-dehydroepiandrosterone (7-oxo-DHEA) can reverse the hypoimmunity in BALB/c mice exposed to chronic mild stress.

METHODSA chronic mild stress animal model was established by subjecting BALB/c mice to a stressful regimen arranged in an unpredicted manner for 4 consecutive weeks. Immunological function alternations under chronic mild stress were assessed by lymphocytes proliferative response to mitogens and NK cell lysis activity test.

RESULTSThe studies showed the correlation between the state of depression and abnormalities in the immune response, such as a decrease of T lymphocytes proliferative response to Con A and suppression of cytotoxic of NK cell. Meanwhile, significant decrease of T3 and T4 levels was also observed. When stressed mice were daily given 7-oxo-DHEA 15 mg.kg-1, lymphocyte proliferative response and the NK cell activity were significantly enhanced and the decreased levels of T3 and T4 were restored in the stressed mice.

CONCLUSION7-oxo-DHEA can improve the depressive symptoms and hypoimmunity of BALB/c mice induced by chronic mild stress as its parent DHEA.

Adjuvants, Immunologic ; pharmacology ; Animals ; Antidepressive Agents ; pharmacology ; Cell Division ; drug effects ; Chronic Disease ; Dehydroepiandrosterone ; analogs & derivatives ; pharmacology ; Killer Cells, Natural ; immunology ; Male ; Mice ; Mice, Inbred BALB C ; Stress, Physiological ; blood ; immunology ; T-Lymphocytes ; immunology ; pathology ; Thyroxine ; blood ; Triiodothyronine ; blood

Ammonium perchlorate (AP), mainly used as solid propellants, was reported to interfere with homeostasis via competitive inhibition of iodide uptake. However, detailed mechanisms remain to be elucidated. In this study, AP was administered at 0, 130, 260 and 520 mg/kg every day to 24 male SD rats for 13 weeks. The concentrations of iodine in urine, serum thyroid hormones levels, total iodine, relative iodine and total protein, and malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) activity in thyroid tissues were measured, respectively. Our results showed that high-dose perchlorate induced a significant increase in urinary iodine and serum thyroid stimulating hormone (TSH), with a decrease of total iodine and relative iodine content. Meanwhile, free thyroxine (FT4) was decreased and CAT activity was remarkably increased. Particularly, the CAT activity was increased in a dose-dependent manner. These results suggested that CAT might be enhanced to promote the synthesis of iodine, resulting in elevated urinary iodine level. Furthermore, these findings suggested that iodine in the urine and CAT activity in the thyroid might be used as biomarkers for exposure to AP, associated with thyroid hormone indicators such as TSH, FT4.
Analysis of Variance ; Animals ; Catalase ; metabolism ; Dose-Response Relationship, Drug ; Homeostasis ; drug effects ; Iodine ; metabolism ; urine ; Male ; Malondialdehyde ; metabolism ; Perchlorates ; pharmacology ; Quaternary Ammonium Compounds ; pharmacology ; Radioimmunoassay ; Rats, Sprague-Dawley ; Superoxide Dismutase ; metabolism ; Thyroid Gland ; metabolism ; Thyrotropin ; blood ; Thyroxine ; blood ; Triiodothyronine ; blood

OBJECTIVETo investigate the effect of selenium supplementation on the selenium status and selenoenzyme, especially the activity and mRNA expression of type 1 deiodinase (D1) in mice with excessive iodine (EI) intake and to explore the mechanism of selenium intervention on iodine-induced abnormities.

METHODSWeanling female BALB/c mice were given tap water or 3 mg/L of iodine or supplemented with 0.5 mg/L or 1.0 mg/L of selenium in the presence of excessive iodine for 5 months. Selenium status, thyroid hormone level, hepatic and renal D1 activity and mRNA expression were examined.

RESULTSExcessive iodine intake significantly decreased the selenium concentration in urine and liver, and the activity of glutathione peroxidase (GSH-Px) in liver. Meanwhile, serum total T4 (TT4) increased while serum total T3 (TT3) decreased. Hepatic D1 enzyme activity and mRNA expression were reduced by 33% and 86%, respectively. Renal D1 enzyme activity and mRNA were reduced by 30% and 55%, respectively. Selenium supplementation obviously increased selenium concentration, activity of GSH-Px and Dl as well as mRNA expression of D1. However, increasing the supplementation of Se from 0.5 to 1.0 mg/L did not further increase selenoenzyme activity and expression.

CONCLUSIONRelative selenium deficiency caused by excessive iodine plays an essential role in the mechanism of iodine-induced abnormalities. An appropriate dose of selenium supplementation exercises a beneficial intervention.

Animals ; Antioxidants ; pharmacology ; Creatinine ; metabolism ; urine ; Dietary Supplements ; Female ; Iodide Peroxidase ; genetics ; metabolism ; Iodine ; toxicity ; urine ; Kidney ; metabolism ; Liver ; metabolism ; Mice ; Mice, Inbred BALB C ; RNA, Messenger ; metabolism ; Selenium ; pharmacology ; urine ; Thyroxine ; blood ; Triiodothyronine ; blood

OBJECTIVESome research has shown that learning and memory function impairments in rats with hypothyroidism are associated with triiodothyronine (T3) deficiency in neurons. This study aimed to investigate the effects of L-T3 administration on learning and memory behaviors in neonatal mice with excitotoxic brain damage.

METHODSSeventy-one 5-day-old ICR neonatal mice were randomly assigned to five groups: controls that received intracerebral and intraperitoneal injections of phosphate buffered saline (PBS) (n=14); a group that received intracerebral injections of ibotenic acid (IA) and intraperitoneal injection of PBS (n=14); 3 groups that received intracerebral injections of IA and intraperitoneal injection of L-T3 at 0.2, 0.5, and 1 microg/kg, respectively (n=14-15). Intraperitoneal injections were done 1, 24, 48, 72 and 96 hrs after intracerebral injections. Learning and memory functions were evaluated by the Y-maze discrimination learning test on postnatal days 33-34.

RESULTSThe learning and memory functions in the highest L-T3 dose group were significantly better than those in the IA, and the lower L-T3 dose groups, presenting with decreased number of trials to criterion[15.8 + or - 4.5 vs 21.3 + or - 6.3 (IA group), 20.5 + or - 6.0 (0.2 microg/kg L-T3 group) or 21.0 + or - 6.5 (0.5 microg/kg L-T3 group); P<0.05], and achieving a higher correct percentage [91.4+ or - 9.5% vs 79.3 + or - 10.0% (IA group), 77.9 + or - 14.2% (0.2 microg/kg L-T3 group) or 80.7 + or - 12.2% (0.5 microg/kg L-T3 group); P<0.05].

CONCLUSIONSHigh-dose L-T3 (1 microg/kg) may improve learning and memory functions in mice following excitotoxic brain damage.

Animals ; Animals, Newborn ; Brain ; drug effects ; Excitatory Amino Acid Agonists ; toxicity ; Female ; Ibotenic Acid ; toxicity ; Learning ; drug effects ; Male ; Maze Learning ; drug effects ; Memory ; drug effects ; Mice ; Mice, Inbred ICR ; Triiodothyronine ; pharmacology

OBJECTIVETo explore the effect of T(3) on the expression of transferrin receptor (TfR) and ferritin (Fn) in K562 cells and its possible mechanism.

METHODSFlow cytometry was used for the detection of TfR expression, radioimmunoassay for Fn expression, RNA/protein band shift assay for the binding activity of iron regulatory protein (IRP) and iron responsive elements (IRE), and RT-PCR for TfR and Fn mRNA levels.

RESULTSDifferent concentration of T(3) significantly increased Fn expression of K562 cells, especially at 100 nmol/L and 200 nmol/L (p < 0.05). However, T(3) had no effect on TfR expression. T(3) decreased the binding activity between IRP and IRE, particularly at concentration of 50 nmol/L. Different concentration of T(3) increased Fn-H mRNA level at different time point while it had no effect on TfR mRNA level.

CONCLUSIONT(3) increased Fn expression of K562 cells through the possible mechanisms of either the post-transcriptional regulation or transcriptional modulation.

Ferritins ; biosynthesis ; drug effects ; genetics ; Flow Cytometry ; Gene Expression Regulation, Leukemic ; drug effects ; Humans ; K562 Cells ; RNA, Messenger ; genetics ; Radioimmunoassay ; Receptors, Transferrin ; biosynthesis ; drug effects ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Triiodothyronine ; pharmacology