Humans ; Perchlorates ; toxicity ; Thyroid Gland ; drug effects

OBJECTIVETo find out the distribution of noniodized salt and related affecting factors in Xinjiang.

METHODUsing NTTST's iodized salt inspection Plan.

RESULTSA total number of 17 973 house holds being surveyed in which 69.4% of those used iodized salt and 30.5% used noniodizd salt. In northern Xinjiang, 7 672 households being surveyed in which 83.9% used iodized salt while in eastern Xinjiang 1 200 house holds being surveyed in which 62.2% used iodized salt. In southern Xinjiang, 9 101 house holds being surveyed in which 58.2% used iodized salt. Data showed a statistically significant difference (chi(2) = 1 329.87, P < 0.01). The noniodized salt comes from shop-on-wheels (57.4%) and rock salt (23.0%). The source of iodine was different in different areas. In eastern and southern Xinjiang it came from shop-on-wheels, while in northern Xinjiang came from retail sites. Factors related to the use of iodized salt were awareness about iodine deficiency disorders (IDD) and income.

CONCLUSIONPrograms on fighting against iodine deficiency in Xinjiang needs more attention, especially in the following aspects as publicity on IDD, administration of salt market and supervision system.

China ; Female ; Humans ; Iodine ; deficiency ; pharmacology ; Male ; Thyroid Gland ; drug effects

OBJECTIVETo explore the effects of lead on the thyroid function of occupationally exposed workers.

METHOD157 workers occupationally exposed to lead in a smelting factory were investigated. The concentration of lead in air at workshop was measured by flame atomic absorption spectrophotometry (FAAS) and the levels of blood lead (PbB) by atomic absorption spectrophotometry (AAS), zinc protoporphyrin (ZPP) by ZnPP meter, as well as the indexes of thyroid function, thyroid-stimulating hormone (TSH), triiodothyronine (T(3)), thyroxin (T(4)), free T(3) (FT(3)), and free T(4) (FT(4)) in serum by radioimmunoassay.

RESULTSThe workers with higher level of blood lead (> 2.88 micro mol/L) showed lower levels of T(3) [(1.54 +/- 0.39) nmol/L] and FT(3) [(5.50 +/- 1.26) pmol/L] than those with lower blood lead level [PbB: (1.92 approximately 2.88) micro mol/L group, T(3): (1.71 +/- 0.45) nmol/L, FT(3): (6.12 +/- 1.64) pmol/L, P < 0.05]. There was no obvious effect of length of service on thyroid hormone of exposed workers.

CONCLUSIONHigher level of blood lead may cause certain damage to thyroid function by inhibiting deiodination of T(4). No obvious relation between length of service and thyroid function was found.

Adult ; Female ; Humans ; Lead ; blood ; toxicity ; Male ; Middle Aged ; Occupational Exposure ; Thyroid Gland ; drug effects ; physiology

OBJECTIVETo assess thyroid disruption induced by sodium pentachlorophenol (PCP) using Organization for Economic Co-operation and Development (OECD) recommended TG 407 method.

METHODSA total of 30 specific pathogen free (SPF) SD adult male and female rats were randomly divided into 3 groups, and treated with water, 0.33 and 30 mg x kg(-1)x d(-1) of PCP-Na by oral gavage for consecutive 28 days, respectively. After final treatment, histological changes of thyroid were observed by hematoxylin-eosin stain, and the levels of thyroid hormones (total thyroxine (TT(4)), free thyroxine (FT(4)), total triiodothyronine (TT(3)), and free triiodothyronine (FT(3))) were determined by radioimmunoassay. The expression levels of thyroid receptors (TRalpha and TRbeta) mRNA and deiodinases (DioI, DioII and DioIII) mRNA in liver were analyzed by RT-PCR.

RESULTSIn high dose group, liver weight coefficient of male and female rats were (4.82 +/- 0.42)% and (4.99 +/- 0.17)%, increased by 36.2% (t = 7.338, P < 0.01) and 41.8% (t = 8.955, P < 0.01), compared to control group ((3.54 +/- 0.14)%, (3.52 +/- 0.19)%), respectively, while the significant changes of kidney or thyroid weight were not observed. In high dose group, the levels of TT(4) and FT(4) in serum of male rats were (64.95 +/- 7.16) nmol/L and (8.16 +/- 2.29) pmol/L, and decreased by 26.6% (t = -3.999, P < 0.01) and 42.3% (t = -4.112, P < 0.01) compared to control group ((88.48 +/- 6.99) nmol/L, (14.13 +/- 1.68) pmol/L). In the same group, FT(4) in serum of female rats was (4.94 +/- 0.89) pmol/L, decreased by 55.5% (t = -3.380, P = 0.012) compared to control group ((11.10 +/- 3.40) pmol/L) and TT(3) and FT(3) in serum of female rats were (1.92 +/- 0.24) nmol/L and (3.05 +/- 0.79) pmol/L, increased by 74.5% (t = 5.263, P < 0.01) and 55.6% (t = 3.495, P < 0.01) compared to control group ((1.10 +/- 0.23) nmol/L, (1.96 +/- 0.32) pmol/L), respectively. PCP-Na didn't affect the expression levels of TRalpha, TRbeta, DioIII mRNA in high dose group, while DioII expression of male rats (0.209 +/- 0.017) down-regulated by 79.2% (t = -5.426, P < 0.01) compared to control group (1.006 +/- 0.137), and DioI expression of female rats (1.844 +/- 0.189) up-regulated by 66.6% (t = 4.359, P < 0.01) compared to control group (1.005 +/- 0.083), indicating DioI and DioII poss different sensitivity to adverse effects induced by PCP-Na between male and female rats. The histopathological results showed that PCP-Na could give rise to hyperplasia of the follicular epithelium cells, and the depletion of colloid. There were no significant changes in serum THs levels and expression of TRalpha, TRbeta, DioI-IIImRNA in low dose group. However, sporadic lymphocytic infiltration, follicles amplification in part and slightly increased in thickness of follicular cells were observed in this group.

CONCLUSIONPCP is a kind of thyroid disrupting chemical.

Animals ; Female ; Liver ; drug effects ; metabolism ; pathology ; Male ; Organ Size ; Pentachlorophenol ; toxicity ; Rats ; Rats, Sprague-Dawley ; Thyroid Gland ; drug effects ; Thyroid Hormones ; blood ; Thyroxine ; blood ; Triiodothyronine ; blood

Animals ; Female ; Herbicides ; toxicity ; Male ; Mice ; Mice, Inbred Strains ; Testis ; drug effects ; Thiocarbamates ; toxicity ; Thyroid Gland ; drug effects ; Weight Gain ; drug effects

OBJECTIVETo study the dose-response relationship between the quantitative morphological stereology on thyroid and different iodine doses in mice.

METHODSWeaning Kunming mice were randomly divided into seven groups. The mice were fed for 100 days with distilled water containing different KIO3 concentrations, i.e. 50, 250, 500, 1 000, 1 500, 2 000, and 3 000 microgram/L respectively. The 50 microgram/L (proper iodine concentration) group was control group, and the groups of 250 approximately 3 000 microgram/L were high iodine groups. The stereology parameters of thyroid follicle and follicular cavities were measured with HPIAS-1000 (High Resolution Pathological Image & word Analysis System). The stereology parameters included mean surface, volume on area, volume on circumference, specific surface, numerical density on area, spherical factor, the percentage of mean surface and mean volume of the follicular epithelial cell in thyroid follicle was further calculated.

RESULTSPositive correlations was observed between the thyroid absolute and relative weight, goiter rate and different iodine doses. And the thyroid absolute and relative weight of mice in the 250 microgram/L group was significantly different from that in 50 microgram/L group. The goiter rate of mice in different high iodine groups was in conformity with that of epidemiological investigation. The goiter rate of mice in 500 microgram/L group was different from that in 50 microgram/L group. Positive correlations were observed between mean surface, volume on area, volume on circumference, spherical factor and iodine doses, but the negative correlations were observed between numerical density on area, specific surface, the percentage of mean surface and mean volume of the follicular epithelial cell in thyroid follicle and iodine doses.

CONCLUSIONSWhen Iodine doses are between 250 approximately 3 000 microgram/L, the dose-response relationship was observed between the morphological stereology parameters of thyroid follicle and follicular cavities and iodine doses, and when the dose of iodine is 250 microgram/L, it is possible to induce colloid goiter of mice. The goiter rates of mice resulted by different high iodine doses were in conformity with that of the epidemiological investigation of people.

Animals ; Dose-Response Relationship, Drug ; Epithelial Cells ; drug effects ; Female ; Iodine ; adverse effects ; pharmacology ; Male ; Mice ; Organ Size ; Thyroid Gland ; drug effects ; pathology

OBJECTIVETo observe the effects of iodine on the level of CD4/CD8 cells and the production of thyroglobulin autoantibody (TGAb) and thyroid peroxidase autoantibody (TPOAb) in Wistar rats and to investigate the role of iodine in thyroid autoimmunity.

METHODSRat models with different iodine intakes including low iodine (LI,), normal iodine (NI,), 5 times normal iodine (5HI), 10 times normal iodine (10HI), 50 times normal iodine (50HI) and 100 times normal iodine (100HI) were established. The amount of iodine intake per rat per day in every group was about < 1, 6.15, 30.75, 61.50, 307.50, 615.00 microg separately. The levels of CD4 and CD8 immune cells in peripheral blood were measured by using flow cytometry. Radioimmunoassay (RIA) was used to determine the titers of TGAb and TPOAb in the serum.

RESULTSIn peripheral blood, the level of CD4 cells in LI group was (57.9 +/- 4.3)%, being much higher than in NI group (51.2 +/- 4.9)%. When the level of CD8 cells in 100HI group was (18.4 +/- 3.1)% showing significantly lower than in NI group (26.5 +/- 4.1)%, thus making the ratio of CD4/CD8 cells in the above two groups (LI: 2.4 +/- 0.40 and 100 HI: 2.7 +/- 0.4) higher than in NI group (1.9 +/- 0.3). As comparing with NI group (2099 +/- 220) CPM, the level of TGAb in LI group (1510 +/- 221) CPM was significantly decreased; while in 50HI group (3986 +/- 286) and 100HI group (3550 +/- 378) CPM, the levels of TGAb were both increased, and the levels of TPOAb in 10HI group (2066 +/- 184) CPM and in 50HI group (2141 +/- 163) CPM were both distinctly lower than in NI group (2372 +/- 245) CPM.

CONCLUSIONSIodine might exert influence on the level of CD4/CD8, and thus the production of thyroid antibodies might directly or indirectly take part in the process of thyroid autoimmunity. Both low iodine and 100 times normal iodine intakes might activate the immune state on some degrees. The effects of iodine on immune responses of TG and TPO antigen in thyroid autoimmunity might not be completely the same.

Animals ; Autoantibodies ; immunology ; Autoimmunity ; drug effects ; CD4-CD8 Ratio ; Drug Overdose ; Iodine ; adverse effects ; deficiency ; Rats ; Rats, Wistar ; Thyroid Gland ; drug effects ; immunology

OBJECTIVETo study the effects of toxicity of ammonium perchlorate (AP) on thyroid of rats.

METHODSEighty-eight Wistar rats were treated orally with different dosages of AP. Three treated groups received 129, 257, 514 mg.kg(-1).d(-1) of AP respectively and one control group drunk water for 13 weeks. Another 3 groups received 1.2, 46.5, 465.0 mg.kg(-1).d(-1) of AP respectively and one control group drunk water for 36 weeks. The behavior and change of body weight in rats were observed. The levels of thyroid hormones in serum were measured and the pathological changes of thyroid tissue were observed as well.

RESULTSThere were no differences in behavior and change of body weight between different AP exposure time. When the rats were treated with AP 514 mg for 13 weeks, free triiodothyronine (FT3, 2.48 pmol/L), free thyroxin (FT4, 13.33 pmol/L) were lower than those in control group (3.24, 20.92 pmol/L respectively, P<0.05). Thyroid-stimulating hormone (TSH, 0.375 mIU/L), thyroglobulin (TG, 3.37 microg/L) were higher than those in control group (0.29 mIU/L, 2.00 microg/L respectively, P<0.05). When the rats were treated with AP 465 mg for 36 weeks, FT3 (2.65 pmol/L) was lower than that in control group (4.97 pmol/L, P<0.01). FT4 in 46.5, 465 mg groups (10.63, 2.17 pmol/L respectively) were lower than that in control group (15.74 pmol/L, P<0.05, P<0.01). TSH in 465 mg group (0.34 mIU/L) was higher than that in control group (0.14 mIU/L, P<0.05). Histopathologic examination showed that follicle proliferation, no colloid in follicle, gore, follicular diminishing or atresia were found in 46.5, 465 mg groups with a dose-effect relationship.

CONCLUSIONSThe toxic effects of AP on the growth of rats were not found, but those on the thyroid of rats were found significantly. Thyroid is the target organ of AP. It is considered that none effect dose of AP for rat thyroid may be 1.2 mg.kg(-1).d(-1), its threshold dose may be 46.5 mg.kg(-1).d(-1).

Animals ; Dose-Response Relationship, Drug ; Female ; Male ; Perchlorates ; toxicity ; Quaternary Ammonium Compounds ; toxicity ; Rats ; Rats, Wistar ; Thyroid Gland ; drug effects ; pathology ; Thyroid Hormones ; blood ; Thyrotropin ; blood

OBJECTIVETo study the effects of ammonium perchlorate (AP) on the levels of thyroid hormone and the testis function of male rats.

METHODSTwenty male rats were randomly divided into 4 groups: control group, low, middle and high AP group. The rats were exposed orally to 0, 130, 260 and 520 mg AP/kg a day for 80 days. The levels of thyroid hormone, testosterone in serum and sperm motility were measured and the testis histological change was observed as well.

RESULTSThe increase of body weight in high AP group was significantly lower than that in the control group (P < 0.01). The organ coefficients of testis and thyroid in high AP group obviously enhanced, as compared with the control group (P < 0.01). The free thyroxin (FT4) levels of serum in all AP treated groups were significantly lower than that of the control group (P < 0.05). There were no differences of serum FT3 levels between all AP groups and control group, while serum TSH levels in middle and high AP groups decreased significantly, as compared with control group (P < 0.01). In terms of sperm motility, the percentage of Grade A and B sperm in middle and high groups were 12.3% +/- 2.52% and 14.8% +/- 5.93%, 17.7% +/- 4.63%, 15.8% +/- 2.28% respectively, which were significantly lower than that (27.8% +/- 8.70%) in control group (P < 0.01). The percentage of Grade D sperm in middle and high groups were 38.0% +/- 3.61% and 40.0% +/- 8.99%, respectively, which were significantly higher than that (17.0% +/- 5.00%) in control group (P < 0.01). No difference of serum testosterone level between all AP groups and control group was observed.

CONCLUSIONAP can influence the levels of thyroid hormone and reduce the serum FT4 levels in rats. The main toxic effects on male reproductive system may decrease the sperm motility.

Animals ; Male ; Perchlorates ; adverse effects ; Quaternary Ammonium Compounds ; adverse effects ; Rats ; Rats, Sprague-Dawley ; Sperm Motility ; drug effects ; Spermatozoa ; drug effects ; Testis ; drug effects ; Thyroid Gland ; drug effects ; Thyrotropin ; blood ; Thyroxine ; blood ; Triiodothyronine ; blood

TSH secretion is controlled by the stimulatory action of hypothalamic TRH and the inhibition via central dopaminergic and somatostatinergic mechanisms as well as by a hypothalamic inhibitory action of thyroid hormones. Metoclopramide is DA2 receptor blockade which can accelerate to elevate the concentration of serum TSH in hypothyroidism, which is accompanied by a progressive loss of dopaminergic tone as demonstrated by a progressive increase in prolaction serum levels, especially in patients with differentiated thyroid carcinoma(DTC). So the period of L-thyroxine withdrawal is contracted and the symptoms of hypothyroidism is released. It's important to monitor and treat DTC patients with radioactive iodide.
Dopamine Antagonists ; pharmacology ; Humans ; Hyperthyroidism ; blood ; drug therapy ; Hypothalamo-Hypophyseal System ; drug effects ; physiology ; Hypothyroidism ; blood ; drug therapy ; Metoclopramide ; chemistry ; pharmacology ; Thyroid Gland ; drug effects ; physiology ; Thyroid Hormones ; blood ; Thyrotropin ; blood