Our results show that 6-n-propyl-2-thiouracil (PTU) treatment producing hypothyroidism induced a significant increase in the expression of PC1/3, PC2, and pro-TRH in the PVN and LH, but not VMN.
Serum IGF-I levels were reduced by approximately 30% in all the 18-day-old hypothyroid animals, and did not correlate with the duration of the hypothyroid state.
These results suggest that epigenetic modification of chromatin might underlie the mechanisms of hypothyroidism-induced down-regulation of reelin and BDNF gene expression in developmental rat hippocampus.
Given the role of the homologous Tom70 gene, the alteration of KIAA0719 expression may contribute to the changes in mitochondrial morphology and physiology caused by hypothyroidism in the developing rat brain.
Short term hypothyroidism alters normal hormone profile in the cycling rat increasing the expression of estrogen receptor-beta and cyp19A1aromatase on estrus, which in turn may stimulate estradiol and prolactin secretion, favouring corpus luteum survival and the subsequent instauration of pseudopregnancy.
In the present study we investigated effects of perinatal iodine deficiency and hypothyroidism on cerebellar cell apoptosis, doublecortin (Dcx) and reelin.
The immunohistochemistry study revealed that the UCP2 protein expression in both renal glomeruli and tubule tissues in the hypothyroidism group was significantly lower than that of control group (renal glomeruli: 0.17±0.02 vs. 0.24±0.04, renal tubule: 0.19±0.02 vs. 0.25±0.02, both P<0.01).
Second, in the control group more than 96% of spermatogonia were PCNA-positive cells; however, hypothyroidism caused the reduction to approximately 25% PCNA staining in spermatogonia.
Northern blot analysis of poly(A)+ RNA from hypothyroid rat interscapular brown adipose tissue demonstrated that the levels of beta 1- and beta 2-AR mRNA per tissue are decreased by 73% and 58% respectively, whereas in hypothyroid heart, only the beta 1-AR mRNA is decreased, by 43%.
These findings may implicate decreases in the number of Purkinje cells and the alterations in the levels of caveolin-1 and synaptotagmin-1 in the impairments of cerebellar development induced by developmental iodine deficiency and hypothyroidism.
In all, our findings demonstrate that myostatin expression is increased in hypothyroid rats, thus supporting a possible role for this factor in the pathogenesis of the muscle loss that may occur in hypothyroidism.
Myosin heavy chain messenger RNA and protein isoform transitions during cardiac hypertrophy. Interaction between hemodynamic and thyroid hormone-induced signals.