Effects of intrauterine exposure to thyroid dysfunction on the development of brain neurons in neonatal rats / 中华内分泌代谢杂志

Objective To investigate the expression of MCT8, DCX, SHH and ARC/ARG3. 1 in brain neurons of neonatal rats exposed to thyroid dysfunction in uterus. Methods Wistar pregnant rats were randomly divided into control group and experimental groups that rats were drunk water with 1, 3, or 5 ppm propylthiouracil ( PTU). The thyroid function and morphological changes of PND1 and PND7 were detected. The expression of MCT8, DCX, SHH, ARC/ARG3. 1 protein in cerebral cortex and hippocampus were detected by Western blot or immunohistochemistry. Results (1) The levels of TT4 decreased significantly in PND1 pups of PTU 3 ppm and 5 ppm groups (P＜0.05 or P＜0.01). The TSH levels significantly increased while FT4 levels significantly decreased in pups of PTU 5 ppm group on PND7 ( P＜0. 05). ( 2) The number NV, V, S, and cross-sectional area of thyroid follicles in offspring of PTU groups were significantly higher than those in the control group on postnatal day 1 and 7 (P＜0.05 or P＜0.01, respectively). (3) The expression of MCT8 in cortex and hippocampus gradually increased with the increase dose of PTU on two postnatal days, but there was significant change in PTU 5 ppm group on PND1 ( P＜0.05). The expression of SHH in pup cortex decreased with the increase of PTU exposure dose on PND7. DCX protein expression in the pup cortex on two postnatal days showed an uptrend with the increase of PTU exposure dose. ARC/ARG3.1 protein levels in hippocampal CA1 area of the pups increased significantly in PTU 1 ppm group on PND1 than that in the same-day control group ( P＜0. 05). Conclusion The damaged neurons of neonatal rats exposed to hypothyroidism in utero can be improved with the gradual recovery of thyroid function, but can not be completely restored to normal level.

Expression of thyroglobulin and thyroid peroxidase in pregnant and lactating rats / 中华地方病学杂志

Objective To observe the mRNA and protein expression of thyroglobulin (Tg) and thyroid peroxidase (TPO) in each trimester of pregnant and lactating Wistar rats.Methods Ninety-six SPFNAF Wistar rats (84 female and 12 male),weighting 220-260 g were involved.All female Wistar rats were randomly divided into 7 groups according to their body mass via the random number table method:control group,early pregnancy group (7 d),midpregnancy group (14 d),late pregnancy group (21 d),early lactation group (7 d),midlactation group (14 d) and late lactation group (21 d),12 rats in each group.The rats were fed with conventional feed and drank deionized water freely.Female rats of the last 6 groups were mated with male rats.Thyroids were collected on the 7 d,14 d and 21 d of their pregnancy and lactation,respectively.The mRNA expression levels of Tg and TPO were detected by quantitative real-time PCR,and the protein expression levels of Tg and TPO were detected by Western blotting.Results The expression levels of Tg mRNA in thyroid tissue in the control group,early,middle and late pregnancy and early,middle and late lactation (1.05 ± 0.01,3.20 ± 0.23,1.88 ± 0.12,2.69 ± 0.20,1.53 ± 0.19,2.37 ± 0.31,2.23 ± 0.12) were significantly different between groups (F =42.864,P ＜ 0.05),and those of pregnancy and lactation groups were higher than those in the control group (P ＜ 0.05).The expression levels of Tg protein were 0.15 ± 0.01,0.38 ± 0.01,0.32 ± 0.02,0.37 ± 0.01,0.21 ± 0.01,0.35 ± 0.01,0.44 ± 0.01,respectively.The differences between groups were statistically significant (F =232.250,P ＜ 0.05).And those of pregnancy and lactation groups were higher than those in the control group (P ＜ 0.05).The expression levels of TPO mRNA in thyroid tissue in the control group,early,middle and late pregnancy and early,middle and late lactation (0.57 ± 0.01,0.74 ± 0.03,0.78 ± 0.13,1.08 ± 0.10,0.98 ± 0.10,1.00 ± 0.07,0.76 ± 0.05) were significantly different between groups (F =15.448,P ＜ 0.05).And those of pregnancy and lactation groups were higher than those in the control group (P ＜ 0.05).The expression of TPO protein were 0.23 ± 0.01,0.41 ± 0.01,0.72 ± 0.02,0.78 ± 0.01,0.49 ± 0.01,0.52 ± 0.01,0.45 ± 0.02,respectively.The differences between groups were statistically significant (F =563.692,P ＜ 0.05).And those of pregnancy and lactation groups were higher than those in the control group (P ＜ 0.05).Conclusions The mRNA and protein expression levels of TPO and Tg have increased in pregnant and lactating rats.This performance may be raleted to thyroid hormone deficiency and mild hypothyroidism.

Comparison of two kinds of induction therapy in childhood acute myeloid leukemia / 临床儿科杂志

Objective To compare the efficacy and safety of induction therapy in 3+7 protocol and 3+10 protocol in children with acute myeloid leukemia (AML). Methods Two protocols were carried out in our hospital during January 2010 to January 2015, namely 3+7 protocol(AML-06,A group) and 3+10 protocol (modified AML protocol, B group). A total of 56 cases aged from 1 year-old to 13 year-old were enrolled in A group with male to female ratio at 31:25. Five of them were classified as FAB M1, 25 as M2, 11 as M4, 10 as M5, 2 as M6 and 3 as M7. Another 44 cases aged from 1 year to 12 years were enrolled in B group with a male to female ratio at 26:18, and 17 cases were classified as FAB M2, 14 as M4, 9 as M5, 2 as M6, and 2 as M7. Efficacy and adverse events were compared between the two groups. Results The complete remission rate (CR) of B group was 70.4%, while CR in A group was 48.2%. Considering the CR, 3+10 protocol showed higher efficacy than 3+7 protocol (P< 0.05). The major adverse event was bone marrow suppression. Treatment-related mortality (TRD) in A group was 1.8%, which was lower than that in B group (2.3%). The overall survival rate in A group was 75.0%, which was lower than that in B group (86.4%, P< 0.05). Conclusions The induction therapy of 3+10 protocol and 3+7 protocol showed effectiveness for AML treatment. The 3+10 protocol showed a higher CR than 3+7 protocol with no TRD increase, indicating that the 3+10 protocol should be recommended for AML treatment in children.

Comparison of orthotropic models of RET/PTC1 rearrangement and BRAFV600E mutation papillary thyroid cancer cell lines in nude mice / 中华内分泌代谢杂志

Objective To observe and compare the different orthotopic models of papillary thyroid cancer ( PTC) cell lines of RET/PTC1 rearrangement and BRAFV600E mutation in nude mice. Methods Human PTC cell lines TPC-1, BHP5-16 and BHP2-7 were used. The genotypes of RET/PTC1 rearrangement and BRAFV600E mutation were determined by realtime-PCR and DNA sequencing analysis. The cells(2×105) were injected into the thyroid gland of nude mice. The nude mice were executed at 4th, 12th week, and then their thyroid tumors were removed and weighed. The levels of thyroid hormone were detected using chemiluminescent immunoassay. Results Both TPC-1 and BHP2-7 cells were identified as RET/PTC1 rearrangement by real time-PCR, and the expression of RET/PTC1 rearrangement in BHP2-7 cell was higher than that of TPC-1 cell. BRAFV600E mutation was found in BHP5-16 cell by DNA sequencing analysis, but was not found in TPC-1 and BHP2-7 cells. There were different characteristics in three orthotopic nude model groups. Tumorigenic rates of TPC-1 and BHP5-16 groups were 100%, but the growth of tumor was more rapid in BHP5-16 group than that in TPC-1 group, with more weight tumor. The changes of thyroid hormone levels in BHP5-16 group and TPC-1 group were the same, which were normal at 4th week and sharply decreased at 12 th week(P0. 05). Conclusions It showed difference in the orthotopic models of PTC cell lines of RET/PTC1 rearrangement and BRAFV600E mutation in nude mice. BRAFV600E mutation has obvious impacts on increasing tumorigenic rate and promotion of tumor growth in the orthotopic model. It should not be ignored that advanced thyroid tumor will lead to the destruction of thyroid function.

Expression of exogenous genes in Chlamydia muridarum by transfection with shuttle vectors / 中华临床感染病杂志

Objective To add an open reading frame in the shuttle vector of pGFP ∷ CM for transfection of exogenous genes into Chlamydia muridarum.Methods The sequence of plasmid pGFP ∷ CM and new open reading frame (including promoter of pgp4,mCherry gene of red fluorescence protein and transcription termination sequence of Chlamydia trachomatis CT579) were amplified by polymerase chain reaction (PCR),and the products were transfected into Stellar competent cells.The recombinant plasmids were identified by PCR,enzyme digestion and sequencing.Then the recombinant plasmid was transfected into plasmid-free strain CMUT3,and the GFP-and mCherry-positive inclusions were observed under the fluorescence microscope.After the ampicillin selection and plaque purification,the purified CMUT3-pGFP-mCherry-CM was identified by indirect immunofluorecesent stain using anti-pgp3 and anti-glgA antibodies.Results The correct recombinant plasmid after sequencing identification,enzyme digestion and PCR amplification was successfully transfected into CMUT3,and the GFP-and mCherry-positive inclusions were observed.The transfected strain CMUT3-pGFP-mCherry-CM was purified after ampicillin selection and plaque purification.The expression of pgp3 and glgA protein in CMUT3-pGFP-mCherry-CM was similar to that in CMUT3-pGFP ∷ CM.Conclusion An open reading frame is successfully added in the plasmid pGFP ∷ CM,and the new plasmid can be transfected into CMUT3 and express exogenous protein,which can be used for further study on the function of single chlamydial protein.

Iodine deficiency up-regulates monocarboxylate transporter 8 expression of mouse thyroid gland / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Iodine deficiency is a major factor affecting thyroid auto-regulation, the quantity of iodine may greatly influence the synthesis of thyroid hormones (THs). It has long been believed that TH enters the cell through passive diffusion. Recent studies have suggested that several transporters could facilitate transportation of TH. The monocarboxylate transporter 8 (MCT8) was identified as a very active and specific TH transporter. The purpose of this study was to investigate whether iodine insufficient affected the expression of MCT8 in the thyroid gland.</p><p><b>METHODS</b>Sixty BALB/c mice were randomly divided into two groups: control group was fed with standard feed (iodine concentration of 300 µg/kg); while low-iodine (LI) group received iodine-insufficient feed (iodine concentration of 20-40 µg/kg). After 3 months, 10 mice of each group were sacrificed. The remaining 20 mice of each group were kept till 6 months. From the LI group, we randomly selected 15 mice and injected triiodothyronine (T3, 100 µg/kg body weight per day) intraperitoneally for 24, 48 or 72 hours (5 mice for each time-point). Then, all the mice were sacrificed. Mouse serum thyroxine (T4), T3, and thyroid-stimulating hormone (TSH) levels were determined by chemiluminescence immunoassay (CIA). The protein content or messenger RNA (mRNA) level of thyroid MCT8 was measured by Western blotting analysis or real time RT-PCR respectively. MCT8 subcellular location in thyroid tissues was probed with immunohistochemistry (IHC) assay.</p><p><b>RESULTS</b>We found that mouse serum T3 and T4 levels decreased and TSH level increased by the end of the third month. Consistent with these findings, there was significant goiter and hypothyroidism in the LI group. Meanwhile, the MCT8 mRNA increased to 1.36-fold of the level in the control group at the 3(rd) month. At 6(th) month, the serum T4 level in LI mice remained at a lower level, and MCT8 mRNA expression continued rising to nearly 1.60-fold compared with the control group. The protein content was also about 3 times higher than that in the control group. IHC results also revealed MCT8 was of higher expression and localized in the cytoplasm of thyroid follicular cells. After providing exogenous T3 to iodine deficient mice, the serum T3 and T4 gradually increased, whereas MCT8 mRNA and protein both started to decrease and returned to the same level as the control group.</p><p><b>CONCLUSION</b>There is a compensatory increase in thyroid MCT8 expression to enhance its capability to transport TH from thyroid to the blood circulation in iodine deficient mice.</p>

Effects of iodine intake on the orthotopic nude mouse model of human papillary thyroid carcinoma cell line TPC-1 / 中华内分泌代谢杂志

Objective To observe the effects of different iodine intake on the thyroid tumor growth and thyroid function in the orthotopic nude mice model of human papillary thyroid carcinoma (PTC) cell line TPC-1.Methods Human PTC cell line TPC-1 (2 × 105) was injected into the left thyroid gland of nude mice.After the operation,the nude mice were randomly divided into three groups:low iodine group (LI),normal iodine group (NI),and high iodine group(HI,50 folds of normal iodine) based on the iodine levels contained in their diet.4 and 12 weeks later,the nude mice were executed,then their thyroid tumors were removed and weighted.The levels of urinary iodine were measured with As3+-Ce4+ catalytic spectrophotometry using ammonium persulfate digestion method.The thyroid hormone level was detected using chemiluminescent immunoassay.The morphology and structure of thyroid tumor tissue was observed by microscope.Results The iodine intervention feeding was successful according to urinary iodine level of LI,NI,and HI groups,paralleled to their iodine intakes.However,the difference of the weight of thyroid tumor in three groups had no statistical significance(P＞0.05).At 4 weeks,compared with control group,the levels of thyroid hormones were normal in NI group,while lower T4 and normal T3 were found in LI group.However,T4 was higher and T3 was lower in HI group (P＜0.05).At 12 weeks,the levels of thyroid hormones all were decreased due to the enlargement of thyroid gland tumor in NI,LI and HI groups.T4 and T3 in LI group were the lowest among three groups,even T4 was below detection limit.T4 was normal and T3 was lower in HI group as compared to control group.Conclusion Iodine intake may not significantly affect tumor growth in the orthotopic nude mice model of human PTC cell line TPC-1,but it has a significant effect on the synthesis of thyroid hormones.

The relationship between thyroid autoantibodies and thyroid function in different populations / 中华内分泌代谢杂志

To explore the relationship between thyroid autoantibodies and thyroid function in school children aged 8-10 years,adults,pregnant women,and lactating women in China,in order to provide reference for the prevention and monitoring of thyroid disease.Healthy 8-10 years old school children (693 cases),adults (698 cases),pregnant women(325 cases),and lactating women(332 cases) from six iodine sufficient areas were enrolled.Serum TSH,FT4,and FT3 were determined by chemiluminescent immunoassay,while antithyroid antibody by radioimmunoassay.The positive rate of thyroid autoantibodies in females was significantly higher than that in the male (5.6％ vs 2.0％ in school children,and 22.8％ vs 3.2％ in adults) ; while positive rate of autoantibodies in pregnant and lactating women (8.9％,8.7％) were significantly lower than that in the other healthy adult women (22.8％).The incidence of abnormal thyroid function in antibody-positive people was higher than that in negative ones in all groups,and abnormal thyroid function showed mainly as subclinical hypothyroidism.In addition,lactating women with negative autoantibodies presented a higher incidence of abnormal thyroid function,mainly as low FT4.The abnormal thyroid function is related with the positive thyroid autoantibodies,indicating that it is essential to follow-up these people with positive antibodies in order to facilitate prevention,early diagnosis,and treatment of thyroid disease.Reference data for thyroid hormones in lactating women should be establisbed as soon as possible.

Reference range for thyroid function indices of 8-10 years old school children in certain regions of China / 中华内分泌代谢杂志

Objective To set up the reference range for thyroid hormones and thyrotropin (TSH) of 8-10 years old school children in certain regions of China to provide reference criteria for diagnosis,treatment,and monitoring of thyroid diseases and related research.Methods A cross-sectional survey was conducted in primary school children aged 8-10 years from six iodine sufficient areas.664 normal school children were selected for establishing reference ranges of thyroid hormones and TSH after crucial screening through questionnaire and laboratory investigation.The serum hormone levels were determined by using chemiluminescent immunoassay (Bayer's reagents),and the reference range of each hormone was displayed as its 95％ central interval.Results The reference ranges of TSH,FT4,FT3,TT4,and TT3 were 1.03-8.42 mIU/L,13.44-20.59 pmol/L,4.75-6.96pmol/L,75.29-152.66 nmol/L,and 1.76-3.35 nmol/L,respectively.There was no significant difference in hormone levels between boys and girls.The eight years old group had slightly higher TT4 level compared with the other age groups.The rural children had higher TSH and TT3 levels and lower FT4 level than the urban children.Conclusion The thyroid hormone and TSH levels are substantially different between school children and adults.Therefore,it is necessary to establish the reference range of thyroid function indices for normal school children in order to diagnose,treat,and monitor thyroid diseases.

Effect of iodine deficiency in pregnant rats on doublecortin and synaptophysin (p38) expressions of fetal brain / 中华内分泌代谢杂志

ObjectiveTo investigate the effects of maternal thyroid dysfunction during pregnancy caused by iodine deficiency of different degrees on doublecortin ( DCX ) and synaptophysin ( p38 ) expressions in fetal brain.Methods Wistar female rats were randomly divided into four groups:adequate iodine ( AI),mild iodine deficiency ( MiID ),moderate iodine deficiency ( MoID ),and severe iodine deficiency ( SID ),according to the total daily iodine supply( fed on an iodine deficient diet with different dosages of KI added in drinking water).Three months later the rats were mated.Serum TSH and thyroid hormones were determined in maternal rats on gestational day 20 using chemiluminescent immunoassay.The iodine contents in urine and histological changes of thyroid gland were observed in pregnant rats.The mRNA and protein levels of DCX and synaptophysin ( p38 ) were analyzed in fetal brain by using real time quantitative RT-PCR and western blotting respectively.Results( 1 ) Iodine contents in urine of pregnant rats were reduced with the decrease of their iodine supply.Compared with group AI,serum TSH was significantly increased [ ( 2.95 ± 1.70 vs 1.31 ± 0.55 ) mU/L,P ＜ 0.05 ],and both TT4 and FT4 were significantly decreased [ ( 14.3±4.1 vs 28.4±19.3 ) nmol/L,P＜0.05 ] and [ ( 10.8±3.6 vs 20.2±8.0) pmol/L,P＜0.01 ] in pregnant rats of SID group.Whereas,a slight rise in TSH,and a mild decline in both TT4and FT4 were found in MoID and MiID groups.However,there were no significant changes in TT3 and FT3 levels among these four groups.( 2 )Histological characteristics of thyroid gland in pregnant rats showed a typical goiter with small follicular hyperplasia and lack of colloid in SID group,moderate follicular hyperplasia with decreased colloid in MoID group; but mild cellular hyperplasia without decrease in follicular size and colloid in MiID group.( 3 ) The mRNA levels of DCX were increased in fetal brains of three iodine deficiency groups compared with AI group,but a statistical significance was found in MoID group.The protein levels of DCX in all experiment groups were significantly increased.Both mRNA and protein expressions of synaptophysin ( p38 )were significantly down-regulated in three iodine deficiency groups.Conclusions Maternal thyroid dysfunction caused by iodine deficiency,even by mild or moderate iodine deficiency,may lead to retardation of fetal neuronal and synaptic growth.

The detection of the binding protein of chlamydiaphage phiCPG1 capsid protein Vp1 on chlamydial outer membrane of serotype D / 中华传染病杂志

Objective To investigate the binding protein of chlamydiaphage phiCPG1 capsid protein Vp1 on chlamydia trachomatis outer membrane.Methods The bacterium with recombinant plasmid Vp1/pet30a( + ) was induced.The expressed protein was purified by gel recycling.FarWestern blot was utilized to' investigate the binding protein of Vp1 on chlamydial outer membrane,including recombinant polymorphic outer membrane protein (rPmp) and major outer membrane protein (MOMP).Results The recombinant protein Vp1 was successfully expressed in E.coli.Monoclonal antibody against Vp1 was used as primary antibody in Western blot,and no specific band was present,which indicated that the monoclonal antibody did not specifically bind with any rPmp.Far-Western blot results showed that there was an obvious band for the rPmpI,but no specific band for other rPmp and MOMP,which suggested that Vp1 could specifically bind with rPmpI protein on the chlamydial outer membrane of serotype D.Conclusions There is a binding site of Vp1 on the chlamydia trachomatis outer membrane.Vp1 may play an important role in the interaction between the chlamydiaphage and the chlamydiae.

Analysis of urinary iodine levels in normal pregnant Chinese women in four districts / 中华内分泌代谢杂志

Objective To analyze the median urinary iodine(MUI)level in normal pregnant women based on World HeMth Organization(WHO) recommended criterion,and to provide the MUI reference values for monitoring and evaluating iodine nutrition during pregnancy and related studies.Methods Total 604 normal pregnant and 192 non-pregnant women(as a comparison)were selected from a cross-sectional survey.These women were all healthy,iodine sufficient,with normal thyroid function,and negative anti-thyroid antibodies.The iodine content in drinking water,edible salt,and urine was determined by standard methods,and serum TSH,FT4,FT3,thyroid peroxidaseantibody(TPOAb),and thyroglobulin antibody(TgAb)were measured using chemiluminescent immunoassay.Resuits (1)The iodine in drinking water was 3.0μg/L indicating such small amount of iodine could be neglected for daily iodine intake.(2)All women consumed iodized salt with the median iodine in salt of 31.7 mg/kg.The daily iodine intake of at least 240 μg could be roughly estimated if an average of 10 g salt was taken per person per day and further subtracted by 20%iodine lost during cooking,which could meet the iodine needs during pregnancy.(3)The MUI of 173.1μg/L was calculated from 604 pregnant women having 174.5,167.0,and 180.7 μg/L during the first,second,and third trimesters,respectively,reaching the optimal level of 150-249 μg/L recommended by WHO for pregnant women.However,our data showed relatively lower levels,not reaching 200μg/L.The MUI of 240.2μg/L was calculated from 192 non-pregnant women,reaching the level of"above requirement"(200-299μg/L) recommended by WHO for adults.(4)All women were euthyroid and antibody-negative,but the TSH level in pregnant women was lower than that in non-pregnant women,in particular during the first trimester,while FT4 and FT3 were considerably decreased compared with the non-pregnant(with an exception of FT4 in the first trimester),and both gradually declined with the gestational age.Conclusions The optimal MUI level of 150-249 μg/,L recommended by WHO can be applied to pregnant Chinese women,but our data provided a relatively low range of 150-200μ/L throughout pregnancy.The higher MUI of 240.2μg/L in non-pregnant women indicated that iodized salt with different contents should be supplied on market to meet the requirement of different groups of population.

Mother-infant's iodine metabolism and thyroid function during lactation with different iodine intakes / 中华内分泌代谢杂志

Objective To study mother and infant's iodine metabolism and thyroid function during lactation with different iodine intakes. Methods Wistar rats were randomly assigned to four groups with severe iodine deficiency (SID), mild iodine deficiency (MiID), normal iodine (NI), and excessive iodine (ExI) intake respectively. All rats were fed on an iodine deficient food and drinking water with different quantities of potassium iodide for 3 months until mating. The urinary iodine, milk iodine, blood iodine, and thyroid hormones (TH) were detected in lactating mother and the offspring rats 14 days after birth. Thyroid weight of mother rats was determined. Thyroid morphology of mother and their offsprings was observed. Results ( 1) Iodine contents in urine, milk, and blood of lactating rats and the offsprings were increased with the increase of iodine supplied in diet. But the change in amplitude between groups was decreased in the other; urine iodine > milk iodine > blood iodine. (2) Serum TT4[ (16. 7±12. 0 vs 36.4±15. 0) nmol/L, P<0.05] was significantly decreased, but TSH [(5.73±2.90vs 1. 38±0.30)mIU/L, P<0.01]and TT3/TT4(6.6±2.7 vs 2. l±0.3,P<0.01) were increased in lactating rats of SID group compared with NI, so as TT4( 10.6±2. 3 vs 16.4±4. 7) nmol/L, P<0.05 ] of offspring rats in SID, but were not in MiID and ExI groups. (3 ) Histological studies showed that small follicular thyroid nodules with follicular hyperplasia occurred in both lactating rats and their offsprings in the SID group, mild swelling in MiID group and polymorphism changes appeared in mother rats of ExI group, but no significant difference appeared in offsprings compared with NI group. Conclusions Severe iodine deficiency will lead to hypothyroidism in mother and infant, but normal iodine nutrition and thyroid function in mother and offspring were maintained through the compensatory action of mother and child in mild iodine deficiency and iodine excess.

Sodium iodide symporter gene expression in thyroid of mice with different iodine intakes / 中华内分泌代谢杂志

Objective To investigate the sodium iodide symporter (NIS) gene expression during different iodine intakes and its function in thyroid autoregulation. Methods BabL/c mice were randomly divided into five groups according to their different iodine intake levels : low iodine (LI), normal iodine (NI), five-fold iodine (5HI) ,ten-fold iodine (10 HI) and fifty-fold iodine (50 HI). After three months and six months administration, they were sacrificed and thyroids were excised. The mRNA and protein expression level were determined by real time quantitative PCR and immunohistochemistry respectively. Iodine content in thyroid tissue was measured with spectrophotometry and thyroid hormone level was measured with radioimmunoassay. Results Compared with NI group, NIS mRNA and protein expression was greatly increased in LI groups. Immunohistochemistry analysis indicated that NIS was mostly located at the basolateral membrane of thyrocyte,suggesting the improved activity in transporting iodine. But when faced with long-term and severe iodine deficiency, the iodine content in thyroid was finally decreased ,and hormone level lowered. On the other hand, in HI groups NIS mRNA and protein expression was greatly down-regulated. There was a tendency of decreasing NIS gene expression level with increasing doses of iodine intakes. In addition, NIS protein was found mainly in intracellular vesicles, rather than at the cell membrane,suggesting the loss of its activity. The iodine content in thyroid tissue was only slightly increased and was not consistent with the iodine intake levels. Conclusion These findings indicate that NIS may be. regulated at transcription, translation and post-translation levels. This phenomenon constitutes a highly specialized intrinsic autoregulatory system that protects thyroid from high doses of iodine, but at the same time ensures adequate iodine uptake for hormone biosynthesis. NIS plays a critical role in thyroid autoregulation mechanism.

Effects of iodine deficiency during pregnancy on fetal iodine metabolism and thyroid function / 中国地方病学杂志

Objective To study the effects of iodine deficiency during pregnancy on fetal iodine metabolism and thyroid function. Methods Wistar dams were randomly divided into four groups: severe iodine deficiency(SID), moderate iodine deficiency(MoID), mild iodine deficiency(MiID) and normal iodine(NI). All the dams were fed with iodine deficient food(iodine contents: 50 μg/kg) and drinking water with different doses of KI (0,54.9,163.8,381.7 μg/L) for 3 months till mating. Iodine was supplied at the dose of 1.24 μg/d(SID), 2.50 μg/d(MoID), 5.00 μg/d(MiID) and 10.00 μg/d(NI), respectively. The dams and their fetuses on gestation of 20 days were studied. Urine iodine of dams and iodine contents in fetal amniotic fluid were measured by As3+-Ce4+catalytic spectrophotometry using ammonium persulfate digestion. And blood iodine in pregnant rats and iodine contents in placental tissue were measured by As3+-Ce4+catalytic spectrophotometry in dry ash of samples in KClO3-ZnSO4-K2CO3-NaCl. Thyroid hormone levels in mother serum and in fetal amniotic fluid were detected by chemiluminascent assay, and their thyroid glands were weighted and carefully observed. Results ①Iodine content in urine and blood of pregnant rats and amniotic fluid of fetal rats reduced along with their decrease of iodine supply. Urine iodine median of rats in 4 groups(NI: 353.7 μg/L; MiID: 115.9 μg/L; MoID: 26.9 μg/L; SID: 0 μg/L) were statistically significant(χ2=32.884, P < 0.01). Blood iodine level in MoID and SID[(29.4±18.6), (11.7± 7.0)μg/L]was significantly lower than that in NI[(49.1±23.0)μg/L, P < 0.05 or < 0.01]. In iodine deficiency groups, there was a decreasing trend in iodine contents of fetal amniotic fluid[MiID: (48.3±23.1)μg/L; MoID: (29.2±14.7)μ/L; SID:(19.5±6.7)μg/L]and an increasing tendency in iodine contents of placental tissue [MiID: (0.57±0.26)μg/g, MoID: (0.53±0.34)μg/g; SID: (0.53±0.15)μg/g], but there was no statistical significance(P>0.05). ②In SID, TT4[(14.3±4.1)nmol/L]and FT4[(10.8±3.6)pmol/L]were lower than that in NI[(28.4±19.3)nmol/L, (20.2±8.0)pmol/L, P < 0.05 or < 0.01], while that in MoID[(22.1±6.1)nmol/L, (18.5±4.1)pmol/L]and MiID[(25.5±13.1)nmol/L, (18.6±8.4)pmol/L]were decreased without statistical significance(P > 0.05). And FT3/FT4 ratio(0.34±0.16), absolute[(48.4±22.7)mg]and relative weights[(144± 76)mg/kg]of thyroid gland in pregnant rats were respectively higher than that in NI[0.16±0.02, (19.5±3.1)mg, (66±10)mg/kg, P<0.01]. But that in MoID[0.19±0.04, (27.0±5.7)mg, (84±19)mg/kg]and MiID[0.17± 0.06, (25.0±8.9)mg, (78±25)mg/kg]were increased without statistical significance(P > 0.05). A visibly congestive enlargement thyroid was found in SID, while thyroid mildly enlarged in MoID and MiID. ③Compared with NI [(2.38±1.55)pmol/L,0.50±0.18], the FT4 levels [(1.07±0.87) pmol/L]in amniotic fluid were significantly decreased (P < 0.05) and the FT3/FT4 ratio (1.96±0.61) was significantly increased (P < 0.01) in SID. There were no statistical significances(P > 0.05) in other 3 groups[MiID: (2.77±0.90)pmol/L,0.46±0.15; MoID: (2.35±0.76)pmoL/L,0.61±0.21]. A visible thyroid enlargement with hyperemia was observed in SID fetus while in other 2 experiment groups their thyroids were only mildly congested. Conclusions Severe iodine deficiency during pregnancy can result in both mother and fetus overt hypothyroidism. The fetal thyroid hormone levels in mild iodine deficiency status is close to normal levels because of maternal and placental compensation. Moreover, both the dam and the fetus suffer from the negative effects in moderate iodine deficiency during pregnancy.

Trimester-specific reference data of thyroid hormones for normal pregnancy / 中华内分泌代谢杂志

Objective To set up the trimester-specific reference ranges of thyroid hormones for normal pregnant women to provide reference criteria for diagnosis, treatment and monitoring or screening of thyroid disease during pregnancy and related research. Methods A cross-sectional survey was conducted in pregnant and non-pregnant women in iodine sufficient areas. A total of 505 normal pregnant women and 153 normal non-pregnant women (as control) were selected for establishing trimester-specific reference ranges of thyroid hormones after rigorous screening through the survey questionnaire and laboratory tests. Thyroid hormones were measured by Bayer automated chemiluminescence immunoassay, and the reference range of each hormone was calculated as median (the 50th percentile value) and two-sided limits (the 2.5th and 97.5th percentile values). Results All women investigated were in iodine sufficient status within optimal urine iodine level. The serum TSH level during the 1st trimester was obviously declined compared with that in the non-pregnant individuals (P < 0.01), and started to rise during the 2nd trimester, but was still not restored to non-pregnant level until the 3rd trimester. Serum FT4 and FT3 levels gradually decreased from the 2nd trimester to the 3rd (P < 0.01), and the TT4 and TT3 levels were markedly elevated since early pregnancy (P < 0.01) and reached peak levels at the 2nd trimester approximately making up to 1.5 times of those in the non-pregnant individuals. Conclusion The thyroid hormone levels during pregnancy differ completely from those of the non-pregnant individuals, and also differ during different gestation periods. Therefore, to establish trimester-specific reference data of thyroid hormones during normal pregnancy may be important for clinical practice.

Effects of High Levels Iodine Intake through Meal on mRNA Expression of Placental and Breast NIS in Rats / 环境与健康杂志

Objective To study the effects of excessive iodine intake through the meal on the expression of mRNA of placental NIS in pregnant rat and breast NIS in lactating rats. Methods Wistar rats, weaning one month, were randomly divided into three groups according to the body weights, i.e., normal iodine (NI), ten fold high iodine(10HI), one hundred fold high iodine(100HI), the ratio of female and male was 2∶1. Iodine intake of the groups were about 6.15, 61.5 and 615.0 mg/d respectively. After 3 months of treatment, the urine iodine was determined by As-Ce-catalytic spectrophotometry. The rats mated and had offspring. Their placenta and breasts were taken on the seventeenth day of pregnancy and tenth day of lactation respectively. Then NIS mRNA expression was determined by RT-PCR. Results The urine iodine increased with the increase of the iodine intake. The urine iodine and iodine intake showed the parallel magnification. Compared with the NI group,AR value of the placental NIS mRNA in 100HI group and the breast NIS mRNA in 10HI and 100HI group significantly decreased. Conclusion Excessive iodine intake may down-regulate the expression of the placental and breast NIS, which presents a protective effect on offspring.

Effects of Different Iodine Intake on Apoptosis and Proliferation of Rats Thyroid Cells / 环境与健康杂志

Objective To explore the effects of iodine on apoptosis and proliferation of the thyroid cells. Methods Wistar rats of one month wean were randomly divided into five groups(low iodine-LI, normal iodine-NI, fivefold high iodine-5 HI, tenfold high iodine-10 HI, fiftyfold high iodine-50 HI), and fed on water containing different concentration of iodine. All groups got prospective iodine intake, that is 0.6, 6.15, 30.75, 61.5, and 307.5 mg/d. After 7 days, 14 days, 28 days, the rats were sacrificed. The proliferation, apoptosis, and apoptosis related genes expression in the thyroid cells were determined by TUNEL, immunohistochemistry and RT-PCR. Results As for short-term of iodine deficiency, no significant change was seen in the mRNA expression of fas and fasL genes, while in the iodine excess groups,the expreesion showed an up-regulation trend as iodine intake increased. Fas and FasL proteins expressions were consistent in LI and NI groups and all of them were negative or weak positive. In the HI groups the stain density increased with iodine intake and treatmnet period increased. Expression of PCNA was enhanced by short-term iodine deficiency, but not by short-term iodine excess. Apoptosis was not observed in all groups. Conclusion Both short-term iodine deficiency and iodine excess have no obvious effects on thyrocytes apoptosis. Proliferation can be induced by short-term iodine deficiency, not by iodine excess. Wistar rats present a strong tolerance to long-term iodine excess.

The Impact of Different Iodine Intakes on Type Ⅰ Iodothyronine Deiodinase Activity and mRNA Expression in Mouse Thyroid Tissue / 生物化学与生物物理进展

Thyroid function ultimately depends on appropriate iodine supply to the gland. Thyroid hormone deiodination is an intrinsic component of the thyroid hormone homeostasis. Type Ⅰ iodothyronine deiodinase (D1) plays an important role in thyroid hormone metabolism and has close relationship with thyroid function. Based on successfully establishing animal models of iodine deficiency and iodine excess in Babl/c mice (Babl/c mice were randomly divided into five groups: low iodine (LI), normal iodine (NI), five-fold iodine (5HI) , ten-fold iodine (10HI) and fifty-fold iodine (50HI) group. Three months and six months after admistration, they were sacrificed and thyroids were excised), the expression level of D1 mRNA were examined by using real time quantitative PCR method. D1 activity was analyzed by 125I-rT3 as substrate combined with ion-exchange chromatography. The thyroid hormone was measured with radioimmunoassay method. The data revealed that in the case of iodine deficiency, both D1 mRNA expression and D1 activity was greatly increased(compared with NI groups, P

ASSAY OF TYPE I IODOTHYRONINE DEIODINASE ACTIVITY AND mRNA EXPRESSION IN THYROID IN RATS OF DIFFERENT IODINE NUTRITION STATUS / 营养学报

Objective: To further investigate the effects of iodine intake on thyroid function and its possible mechanism. Method: Wistar rats were randomly divided into six groups: LI, NI, 5HI, 10HI, 50HI, 100HI. Different groups of rats were fed with feed and water of different iodine content. 3, 6 and 12 months after administration, they were sacrificed and thyroids were excised. The thyroid D1 mRNA expression level was determined by RT-PCR semi-quantitative method and the thyroid D1 activity was analyzed by using 125I-rT3 as substrate. Results: Compared with NI group, the thyroid D1 mRNA expression was decreased in all HI groups, and D1 activity was significantly higher in LI group and lower in HI groups. There was a tendency of decrease in D1 activity with increased doses of iodine intakes. Conclusion: In the case of iodine deficiency, thyroid D1 activity will increase greatly in order to convert more T4 to T3, but deficient iodine intake doesn’t improve thyroid D1 mRNA expression. Excess iodine can inhibit both thyroid D1 mRNA expression and its activity.