scholarly journals EFFECTS OF SILVER NANOPARTICLES ON THYROID GLAND STRUCTURE AND FUNCTION IN FEMALE RATS

Author(s):  
Amal A Sulaiman ◽  
Noori M Luaibi ◽  
Hiba A Qassim

Objective: Due to their unique properties, silver nanoparticles (AgNPs) gained a broad utilization in nano-based industries and medicine, which may expose human to increased levels of NPs. However, little is known about their potential harmful effects on endocrine physiology. Hence, this study aimed to investigate the potential dose- and time-dependent outcomes of AgNPs on serum levels of thyroid hormones and thyroid gland histology in female rats.Methods: A total of 60 female rats were divided into three groups (each of 20 animals), treated with AgNPs for (10, 20, and 30) days. Within each treatment period, animals were assigned into four subgroups each of five rats; control treated with vehicle and the others treated with 12.5, 25, and 50 mg/kg of AgNPs, respectively, by intraperitoneal injection. At the end of treatments, all rats were sacrificed; blood samples were obtained and analyzed for serum levels of T3, T4, and thyroid-stimulating hormone (TSH). Thyroid gland was removed and weighed then kept in buffered formalin solution for microscopic examination.Results: The data showed a significant increase in the weight of the thyroid gland after 20 and 30 days of the treatment with 50 mg/kg of AgNPs, while the 25 mg/kg dose of AgNps resulted in significant increase only after 30 days. Serum levels of T3 and TSH were nonsignificantly altered by AgNPs in all the treatment groups. Thyroxin levels (T4) were significantly decreased after long-term exposure. Histological specimens of AgNPs treated group showed disturbance of the normal architecture of the thyroid tissue with degeneration of thyroid follicles and desquamated luminal cells.Conclusion: The results of the current study suggested the possible disrupting potential of long-term exposure to high level of AgNPs on thyroid gland function and histology in female rats.

Endocrinology ◽  
2019 ◽  
Vol 161 (5) ◽  
Author(s):  
Haruki Fujisawa ◽  
Manassawee Korwutthikulrangsri ◽  
Jiao Fu ◽  
Xiao-Hui Liao ◽  
Alexandra M Dumitrescu

Abstract Selenocysteine insertion sequence-binding protein 2, SBP2 (SECISBP2), is required for selenoprotein synthesis. Partial SBP2 deficiency syndrome manifests characteristic thyroid function tests. The Sbp2 deficiency mouse model, Sbp2 inducible conditional knockout (iCKO), replicates this thyroid phenotype and was used for pathophysiologic investigations. As selenoproteins have an antioxidative role in thyroid gland function, their deficiencies have potential to affect thyroid hormone (TH) synthesis. Sbp2 iCKO mice had larger thyroids relative to body weight and increased thyroidal thyroxine (T4) and triiodothyronine (T3) content while 5' deiodinases enzymatic activities were decreased. Possible mechanisms for the discrepancy between the increased thyroidal T3 and normal circulating T3 were investigated in dynamic experiments. Treatment with bovine thyroid-stimulating hormone (TSH) resulted in increased delta T4 in Sbp2 iCKO mice, indicating increased availability of preformed thyroidal TH. Next, the recovery of TH levels was evaluated after withdrawal of chemical suppression. At one day, Sbp2 iCKO mice had higher serum and thyroidal T3 concomitant with lower TSH, confirming increased capacity of TH synthesis in Sbp2 deficiency. Decreased TH secretion was ruled out as serum and thyroidal TH were high in Sbp2 iCKO mice. Treatment with a low-iodine diet also ruled out thyroidal secretion defect as both serum levels and thyroidal TH content similarly declined over time in Sbp2-deficient mice compared to wild-type (Wt) mice. This study provides evidence for unsuspected changes in the thyroid gland that contribute to the thyroid phenotype of Sbp2 deficiency, with increased thyroidal T4 and T3 content in the setting of increased TH synthesis capacity contributing to the circulating TH levels while thyroidal secretion is preserved.


2021 ◽  
Vol 11 (9) ◽  
pp. 852-861
Author(s):  
Snizhana Sokolnyk ◽  
Iryna Sokolnyk ◽  
Dmytro Nechytaylo ◽  
Dmytro Kolesnik ◽  
Mykola Hinhuliak ◽  
...  

Diseases of thyroid gland (TG) rank first among all endocrine pathologies and remain one of the most difficult problems. According to the statistics of Ministry of Health of Ukraine, the prevalence of hypothyroidism in children does not exceed 0.035%. However, the relatively low rate can be explained by the low level of detection and diagnosis of this pathological condition due to the variability and low specificity of its symptoms. More acceptable for practice are methods of ultrasound diagnosis of the thyroid gland and laboratory examination of the content of thyroid-stimulating hormone in the serum. Aim. To evaluate the results of ultrasound examination of the thyroid gland in children with hypothyroidism. Methods. The results are based on a survey of 94 children with hypothyroidism living in the Chernivtsi region aged 2 to 10 years. An ultrasound examination of the thyroid gland, determination of the level of thyroid hormones (thyroid stimulating hormone (TSH), free thyroxine (fT4) was performed. Statistical analysis was performed using standard methods using the StatSoft software package © Statistica® 6.0 for Microsoft® Windows XP. Results. Analysis of the results of the study showed that in 59.6% of cases (56 out of 94) the diagnosis was made by screening for congenital hypothyroidism, and in 40.4% of cases (38 out of 94) the disease was diagnosed outside the screening. According to the results of our ultrasound, it was found that in 29 patients the thyroid tissue was not visualized in a typical place or its total volume was much less than normal. Of these, in 12 individuals, thyroid tissue was not reliably visualized at the site of TG projection, and in 17 cases was hypoplasia. In 65 patients, the TG was in a typical place, and its volume corresponded to the norm on the surface area of the body. In 85 people, regardless of the state of functional activity of the TG had a heterogeneous echostructure of the thyroid parenchyma), in 9 people the echostructure of the thyroid parenchyma was homogeneous. In thyroid hypoplasia, the level of TSH was at lower values (p <0.05) compared with thyroid dystopia. Conclusion. Sonographic examination of the thyroid gland has a high level of information. In cases of malformations of the thyroid gland there is a more pronounced degree of thyroid insufficiency.


2021 ◽  
pp. 1-8
Author(s):  
Niamh McGrath ◽  
Colin Patrick Hawkes ◽  
Stephanie Ryan ◽  
Philip Mayne ◽  
Nuala Murphy

Scintigraphy using technetium-99m (<sup>99m</sup>Tc) is the gold standard for imaging the thyroid gland in infants with congenital hypothyroidism (CHT) and is the most reliable method of diagnosing an ectopic thyroid gland. One of the limitations of scintigraphy is the possibility that no uptake is detected despite the presence of thyroid tissue, leading to the spurious diagnosis of athyreosis. Thyroid ultrasound is a useful adjunct to detect thyroid tissue in the absence of <sup>99m</sup>Tc uptake. <b><i>Aims:</i></b> We aimed to describe the incidence of sonographically detectable in situ thyroid glands in infants scintigraphically diagnosed with athyreosis using <sup>99m</sup>Tc and to describe the clinical characteristics and natural history in these infants. <b><i>Methods:</i></b> The newborn screening records of all infants diagnosed with CHT between 2007 and 2016 were reviewed. Those diagnosed with CHT and athyreosis confirmed on scintigraphy were invited to attend a thyroid ultrasound. <b><i>Results:</i></b> Of the 488 infants diagnosed with CHT during the study period, 18/73 (24.6%) infants with absent uptake on scintigraphy had thyroid tissue visualised on ultrasound (3 hypoplastic thyroid glands and 15 eutopic glands). The median serum thyroid-stimulating hormone (TSH) concentration at diagnosis was significantly lower than that in infants with confirmed athyreosis (no gland on ultrasound and no uptake on scintigraphy) (74 vs. 270 mU/L), and median free T4 concentration at diagnosis was higher (11.9 vs. 3.9 pmol/L). Six of 10 (60%) infants with no uptake on scintigraphy but a eutopic gland on ultrasound had transient CHT. <b><i>Conclusion:</i></b> Absent uptake on scintigraphy in infants with CHT does not rule out a eutopic gland, especially in infants with less elevated TSH concentrations. Clinically, adding thyroid ultrasound to the diagnostic evaluation of infants who have athyreosis on scintigraphy may avoid committing some infants with presumed athyreosis to lifelong levothyroxine treatment.


2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Dianna Liu ◽  
Feng Chen ◽  
Xue Yu ◽  
Linlin Xiu ◽  
Haiyan Liu ◽  
...  

Sargassum species combined with Glycyrrhiza uralensis is a famous herbal pair in traditional Chinese medicine, as one of the so-called “eighteen antagonistic medicaments.” In the Chinese Pharmacopoeia, two different species of Sargassum, Sargassum pallidum and Sargassum fusiforme, are recorded but they are not clearly differentiated in clinical use. In this study, we aimed to determine whether the two species of Sargassum could result in different effects when combined with G. uralensis in Haizao Yuhu Decoction (HYD), which is used for treating thyroid-related diseases, especially goiter. HYD containing S. pallidum or S. fusiforme was administered to rats with propylthiouracil-induced goiter. After 4 weeks, pathological changes in the thyroid tissue and the relative thyroid weight indicated that HYD containing S. pallidum or S. fusiforme protected thyroid tissues from propylthiouracil damage. Neither species increased the propylthiouracil-induced decrease in serum levels of thyroid hormones. However, there were some differences in their actions, and only HYD containing S. fusiforme abated the propylthiouracil-induced elevation of serum thyroid-stimulating hormone levels and activated thyroglobulin mRNA expression.


2017 ◽  
Vol 22 (5) ◽  
pp. 414-433 ◽  
Author(s):  
Abdulmaged M. Traish ◽  
Ahmad Haider ◽  
Karim Sultan Haider ◽  
Gheorghe Doros ◽  
Farid Saad

Objectives: In the absence of large, prospective, placebo-controlled studies of longer duration, substantial evidence regarding the safety and risk of testosterone (T) therapy (TTh) with regard to cardiovascular (CV) outcomes can only be gleaned from observational studies. To date, there are limited studies comparing the effects of long-term TTh in men with hypogonadism who were treated or remained untreated with T, for obvious reasons. We have established a registry to assess the long-term effectiveness and safety of T in men in a urological setting. Here, we sought to compare the effects of T on a host of parameters considered to contribute to CV risk in treated and untreated men with hypogonadism (control group). Patients and Methods: Observational, prospective, cumulative registry study in 656 men (age: 60.7 ± 7.2 years) with total T levels ≤12.1 nmol/L and symptoms of hypogonadism. In the treatment group, men (n = 360) received parenteral T undecanoate (TU) 1000 mg/12 weeks following an initial 6-week interval for up to 10 years. Men (n = 296) who had opted against TTh served as controls. Median follow-up in both groups was 7 years. Measurements were taken at least twice a year, and 8-year data were analyzed. Mean changes over time between the 2 groups were compared by means of a mixed-effects model for repeated measures, with a random effect for intercept and fixed effects for time, group, and their interaction. To account for baseline differences between the 2 groups, changes were adjusted for age, weight, waist circumference, fasting glucose, blood pressure, and lipids. Results: There were 2 deaths in the T-treated group, none was related to CV events. There were 21 deaths in the untreated (control) group, 19 of which were related to CV events. The incidence of death in 10 patient-years was 0.1145 in the control group (95% confidence interval [CI]: 0.0746-0.1756; P < .000) and 0.0092 in the T-treated group (95% CI: 0.0023-0.0368; P < .000); the estimated difference between groups was 0.0804 (95% CI: 0.0189-0.3431; P < .001). The estimated reduction in mortality for the T-group was between 66% and 92%. There were also 30 nonfatal strokes and 26 nonfatal myocardial infarctions in the control group and none in the T-treated group. Conclusion: Long-term TU was well tolerated with excellent adherence suggesting a high level of patient satisfaction. Mortality related to CV disease was significantly reduced in the T-group.


1971 ◽  
Vol 68 (3) ◽  
pp. 585-596 ◽  
Author(s):  
O. Helmer Serensen ◽  
Inge Hindberg

ABSTRACT The influence of short-term and long-term treatment with gonadal hormones on the response to calcitonin was investigated in the rat. Oestrogen-treatment, short-term as well as long-term, resulted in a reduced responsiveness to calcitonin. Long-term treatment with androgens enhanced the hypocalcaemic effect of calcitonin in castrated rats of either sex, but reduced the effect in intact animals. No sex differences could be registered in the sensitivity to calcitonin, when intact animals were compared according to age, while marked differences were observed, when the animals were compared according to weight. There was a linear decrease in the response to calcitonin with increasing age in rats of both sexes. An intraperitoneal calcium load was followed by an acute rise in the serum calcium levels. The adult animals counteracted the hypercalcaemia more slowly than the young ones. Significant differences also occurred between male and female rats, the rise in the serum calcium concentration being much more pronounced in the latter group. The hypocalcaemic activity of thyroid tissue from rats of both sexes and of various ages showed considerable variations, but no differences correlated to age or sex.


2006 ◽  
Vol 189 (1) ◽  
pp. 77-88 ◽  
Author(s):  
Martina Böttner ◽  
Julie Christoffel ◽  
Hubertus Jarry ◽  
Wolfgang Wuttke

Hormone replacement therapy (HRT) has been used for several decades to treat menopausal discomforts. However, in the light of recent studies that draw attention to the potential hazards of conventional HRT, various attempts have been undertaken to search for alternatives to classical HRT. Phytoestrogens are claimed to be capable of positively influencing menopausal symptoms, including hot flushes. We designed a long-term study of 3 months to assess the effects of subcutaneous and orally fed 17β-estradiol (E2), as well as the actions of resveratrol (RES) on pituitary function in female rats. Our results have demonstrated that RES binds with a 10-fold lower affinity to estrogen receptor (ER)-α than to ERβ. The data from the in vivo study revealed that a dosage of 5 μg and 50 μg RES/kg bodyweight per day given to ovariectomized (OVX) rats achieved serum levels of 1.0 and 8.1 μM respectively. Long-term treatment of OVX rats with RES revealed no estrogenic potential on pituitary function in vivo as assessed by LH and prolactin secretion and by regulation of mRNAs for LHα, LHβ, and GnRH receptor. Subcutaneous treatment with E2 in silastic capsules exerted stronger effects on LH and prolactin secretion, as well as on LHβ, LHα, GnRH receptor, and ERβ mRNA regulation compared with orally applied estradiol benzoate despite comparable serum levels. Levels of aryl hydrocarbon receptor (AhR) mRNA in the pituitary were increased following OVX and attenuated by long-term E2 treatment, whereas RES did not modulate AhR mRNA expression.


2012 ◽  
Vol 06 (02) ◽  
pp. 184-190 ◽  
Author(s):  
Mahadevi B Hosur ◽  
S R Puranik ◽  
Shrinivas Vanaki ◽  
Surekha R Puranik

ABSTRACTObjective: Apart from its well-known deleterious dental and skeletal effects, fluoride excess can have toxic effects on many other tissues. Fluoride, when in excess, is known to interfere with thyroid gland function. Fluoride-induced thyroid disturbances similar to those observed in iodine deficiency state in spite of adequate iodine intake have been documented. Similar thyroid disturbances in individuals with dental fluorosis have not been well studied in populations with endemic fluorosis. This work was undertaken to study the effects of fluoride-induced thyroid disturbances in individuals with dental fluorosis.Methods: The study group included 65 subjects with dental fluorosis from endemic fluorosis populations. An additional control group was comprised of 10 subjects without dental fluorosis. The drinking water fluoride levels of the study populations were analyzed. Serum free FT3, FT4, and TSH levels of both groups were assessed.Results: All subjects with dental fluorosis had serum levels of thyroid hormones (FT3, FT4, and TSH) within the normal range, with the exception of 1 individual, who had elevated levels of TSH. Statistical significance was found when FT3 and TSH values were compared with different Dean’s index groups by a 1-way ANOVA test: FT3 (F = 3.4572; P=.0377) and TSH (F = 3.2649 and P=.0449).Conclusions: Findings of this study did not show any significant alterations in the levels of the thyroid hormones FT3, FT4, and TSH in subjects with dental fluorosis. Our observations suggest that thyroid hormone levels were not altered in subjects with dental fluorosis. Hence, future studies of this kind, along with more detailed investigations are needed. (Eur J Dent 2012;6:184-190)


2001 ◽  
Vol 171 (1) ◽  
pp. 193-198 ◽  
Author(s):  
VM da Costa ◽  
DG Moreira ◽  
D Rosenthal

The effects of aging on human or animal thyroid function are still not well defined. We evaluated some aspects of thyroid function during aging using an animal model (young and old Dutch-Miranda rats). In old rats of both genders, serum thyroxine (T4) decreased but serum thyrotrophin (TSH) remained unaltered, suggesting a disturbance in the pituitary-thyroid feedback mechanism during aging. Serum tri-iodothyronine (T3) only decreased in old males, possibly because female rats are almost twice as efficient in hepatic T4 to T3 deiodination. Thyroidal T4-5'-deiodinase activity did not change much during aging, although it decreased slightly in males. Thyroidal iodothyronine-deiodinase type I mRNA expression but not total thyroidal enzymatic activity were higher in female than in male rats. Thus, ovarian/testicular hormones may modulate the expression and/or the activity of hepatic and thyroidal type I iodothyronine-deiodinase. Thyroperoxidase (TPO) and thyroglobulin (Tg) expression were higher in young male rats than in females. In males, TPO and Tg gene expression decreased with aging, suggesting that androgens might increase their expression. Our results showed that aging induces real changes in rat thyroid gland function and regulation, affecting at least pituitary, thyroid and liver functions. Furthermore, some of these changes were gender related, indicating that gonadal hormones may modulate thyroid gland function and regulation.


1995 ◽  
Vol 269 (5) ◽  
pp. G699-G705 ◽  
Author(s):  
A. Nishida ◽  
A. Kobayashi-Uchida ◽  
S. Akuzawa ◽  
Y. Takinami ◽  
T. Shishido ◽  
...  

Female rats were treated orally for 13 wk with YM022 (300 mumol.kg-1.day-1) and with omeprazole (400 mumol.kg-1.day-1) or famotidine (900 mumol.kg-1.day-1) with or without YM022. At 2 h after the last dose, YM022 and omeprazole markedly inhibited basal and pentagastrin-induced acid secretion. Famotidine was less potent than YM022 and omeprazole against both secretions. The degree of increase in plasma gastrin level in the three groups was parallel to the antisecretory potencies of the drugs. At 14 days after the cessation of omeprazole treatment, the secretory response to pentagastrin increased above that of the control. This hyperresponse lasted for > or = 56 days. In the famotidine-treated group, a small increase in secretory response to pentagastrin was observed but was not statistically significant. The increase in secretory response to pentagastrin was paralleled by an increase in mucosal cell mass. In contrast, YM022 not only exhibited a long-lasting inhibition of pentagastrin-induced acid secretion but also prevented the hyperresponse to pentagastrin caused by omeprazole. These results indicate that the hypergastrinemia caused by long-term administration of antisecretory drugs increases mucosal secretory response to pentagastrin through a gastrin/cholecystokinin B receptor-mediated pathway in rats.


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