Central and peripheral administrations of levothyroxine improved memory performance and amplified brain electrical activity in the rat model of Alzheimer's disease

Shabani, Sahreh; Sarkaki, Alireza; Mard, Seyyed Ali; Ahangarpour, Akram; Khorsandi, Layasadat

doi:10.1016/j.npep.2016.09.003

Cited by 18 publications

(11 citation statements)

References 44 publications

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“…This not only provided a normal reference value range for this study, but also provided basic data for the study on thyroid-related diseases in this region. In rat experiments, the exogenous administration of L-T4 included intragastric perfusion, subcutaneous injection, intraperitoneal injection, and subcutaneous mini-pump implantation [15][16][17][18][19] . The advantage of oral administration is that it is easy to operate and does not cause irritation to rats, however, it cannot properly control the dose, and that is easily affected by the food intake (or water intake) and digestive function of rats.…”

Section: Discussionmentioning

confidence: 99%

Development of a Rat Model for Evaluating Thyroid-Stimulating Hormone Suppression after Total Thyroidectomy

Jin

Sugitani

2021

J Nippon Med Sch

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Background: This study aimed to induce an animal model for TSH suppression therapy after total thyroidectomy in rats.Methods: A total of 60 Wistar rats were randomly divided into 6 groups, including sham-operated group (SO group),total thyroidectomy group (TD group), L-T4 treatment I group (TS-I group), II group (TS-II group), III group (TS-Ⅲ group), and IV group (TS-Ⅳ group), in which the rats were accordingly treated with 1.4, 1.6, 1.8, and 2.0 μg/100g body weight after total thyroidectomy.Results: HE staining in the TD group and all L-T4 treated rats showed that the resected tissue was normal thyroid gland in rats, and no residual thyroid tissue was found in the neck tissue of the crosssection of thyroid gland. The serum levels of T3 in the TS-II group were not significantly different from those in the SO group, whereas the serum level of T4 was slightly higher than that in the SO group, and the serum level of TSH was slightly lower than that in the SO group. Conclusions:Rats subcutaneously injected with L-T4 at a dose of 1.6 μg/100g body weight for 15 days after total thyroidectomy could induce an animal model for TSH suppression therapy. It may be used as an animal model for TSH suppression therapy.

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Section: Discussionmentioning

confidence: 99%

Development of a Rat Model for Evaluating Thyroid-Stimulating Hormone Suppression after Total Thyroidectomy

Jin

Sugitani

2021

J Nippon Med Sch

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“…Thyroid hormones especially improve hippocampus-dependent learning and memory and hippocampal synaptic plasticity [49–51] as well as hippocampal neurogenesis [52]. Thyroxine treatment improves spatial learning in a water maze probably by induced increased cholinergic activity [53] and rescues spatial cognitive deficits and dentate gyrus electrical activity in a rat model of Alzheimer’s disease [54]. T3 and T4 reduce GABA-evoked and spontaneous inhibitory synaptic currents up to 50%, whereas T4 in contrast to T3 was ineffective in decreasing extra-synaptic GABA currents [55].…”

Section: Discussionmentioning

confidence: 99%

Age and cognitive status dependent differences in blood steroid and thyroid hormone concentrations in intact male rats

et al. 2019

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Background Age-dependent alterations of hormonal states have been considered to be involved in age related decline of cognitive abilities. Most of the studies in animal models are based on hormonal substitution in adrenal- and/or gonadectomized rodents or infusion of steroid hormones in intact rats. Moreover, the manipulations have been done timely, closely related to test procedures, thus reflecting short-term hormonal mechanisms in the regulation of learning and memory. Here we studied whether more general states of steroid and thyroid hormone profiles, independent from acute experiences, may possibly reflect long-term learning capacity. A large cohort of aged (17–18 months) intact male rats were tested in a spatial hole-board learning task and a subset of inferior and superior learners was included into the analysis. Young male adult rats (16 weeks of age) were also tested. Four to 8 weeks after testing blood plasma samples were taken and hormone concentrations of a variety of steroid hormones were measured by gas chromatography-tandem mass spectrometry or radioimmunoassay (17β-estradiol, thyroid hormones). Results Aged good learners were similar to young rats in the behavioral task. Aged poor learners but not good learners showed higher levels of triiodothyronine (T3) as compared to young rats. Aged good learners had higher levels of thyroid stimulating hormone (TSH) than aged poor learning and young rats. Both aged good and poor learners showed significantly reduced levels of testosterone (T), 4-androstenedione (4A), androstanediol-3α,17β (AD), dihydrotestosterone (DHT), 17-hydroxyprogesterone (17OHP), higher levels of progesterone (Prog) and similar levels of 17β-estradiol (E2) as compared to young rats. The learning, but not the memory indices of all rats were significantly and positively correlated with levels of dihydrotestosterone, androstanediol-3α,17β and thyroxine (T4), when the impacts of age and cognitive division were eliminated by partial correlation analyses. Conclusion The correlation of hormone concentrations of individuals with individual behavior revealed a possible specific role of these androgen and thyroid hormones in a state of general preparedness to learn.

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“…Ibo (0.5 µl at 0.6 µg/µl) was dissolved in PBS (0.01 M) and injected into DG region of the hippocampus bilaterally (Shabani et al 2016;Ogino et al, 2014).…”

Section: Methodsmentioning

confidence: 99%

“…In our recently study have been shown that administration of Aβ1-42 into the DG resulted in spontaneous discharges impairment of neurons and the memory process disorder (Shabani et al, 2016).…”

mentioning

confidence: 87%

The regulation of pituitary-thyroid abnormalities by peripheral administration of levothyroxine increased brain-derived neurotrophic factor and reelin protein expression in an animal model of Alzheimer’s disease

Shabani

Mard

Sarkaki

et al. 2018

Can. J. Physiol. Pharmacol.

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Alzheimer’s disease (AD) is associated with decreased serum levels of thyroid hormones (THs), increased levels of thyroid-stimulating hormone (TSH), and decreased protein expression of brain-derived neurotrophic factor (BDNF) and reelin in the hippocampus. In this study, we have evaluated the effect of subcutaneous administration of levothyroxine (L-T4) on levels of THs and TSH as well as protein expression of BDNF and reelin in AD rats. To make an animal model of AD, amyloid-beta peptide (Aβ) plus ibotenic acid were infused intrahippocampally, and rats were treated with L-T4 and (or) saline for 10 days. The levels of THs and TSH were measured by ELISA kits. Protein synthesis was detected by Western blotting method. Results have been shown that serum level of THs, BDNF, and reelin protein expression in the hippocampus were significantly decreased (P < 0.001) in AD animals and elevated significantly in AD rats treated with L-T4 (P < 0.01). Data showed that TSH level significantly decreased in AD rats treated with L-T4 (P < 0.05). These findings indicated that L-T4 increased BDNF and reelin protein expression by regulation of serum THs and TSH level in Aβ-induced AD rats.

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Central and peripheral administrations of levothyroxine improved memory performance and amplified brain electrical activity in the rat model of Alzheimer's disease

Cited by 18 publications

References 44 publications

Development of a Rat Model for Evaluating Thyroid-Stimulating Hormone Suppression after Total Thyroidectomy

Development of a Rat Model for Evaluating Thyroid-Stimulating Hormone Suppression after Total Thyroidectomy

Age and cognitive status dependent differences in blood steroid and thyroid hormone concentrations in intact male rats

The regulation of pituitary-thyroid abnormalities by peripheral administration of levothyroxine increased brain-derived neurotrophic factor and reelin protein expression in an animal model of Alzheimer’s disease

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