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Aims: To determine the impact of hypothyroidism on the bladder and urethral functions as well as in the activation of the pubococcygeous (Pcm) and bulbospongiosus (Bsm) during micturition., Methods: Age-matched control and methimazole-induced hypothyroid female rabbits were used to simultaneously record cystometrograms, urethral pressure, and the reflex activation of Pcm and Bsm during the induced micturition. Urodynamic and urethral variables were measured. Activation or no activation of the Pcm and Bsm during the storage and voiding phases of micturition were categorized as 1 or 0. Significant differences (P ≤ 0.05) between control and hypothyroid groups were determined with unpaired Student-t or Mann-Whitney tests., Results: One-month induced hypothyroidism increased the residual volume and threshold pressure while the opposite was true for the voided volume, maximal pressure, and voiding efficiency. Urethral pressure was also affected as supported by a notorious augmentation of the urethral resistance, among other changes in the rest of measured variables. Hypothyroidism also affected the reflex activation of the Pcm in the voiding phase of micturition., Conclusions: Our findings demonstrate hypothyroidism impairs the bladder and, urethral functions, and reflex activation of Pcm and Bsm affecting the micturition in female rabbits., (© 2018 Wiley Periodicals, Inc.)

Hypothyroidism is associated with the development of non-alcoholic steatohepatitis, but cellular mechanisms have been scarcely analyzed. Thyroid hormones regulate the synthesis and secretion of bile acids that are endogenous ligands of the farnesoid receptor (FXRα), which have been involved in the development of non-alcoholic steatohepatitis. However, the relationship between thyroid hormones and FXRα expression in the liver is yet unknown. Control ( n =6) and methimazole-induced hypothyroid ( n =6) female rabbits were used to evaluate the amount of lipids and glycogen, vascularization, hepatocytes proliferation, immune cells infiltration, and expression of FXRα. Student- t or Mann-Whitney U tests were carried out to determine significant differences. Hypothyroidism induced steatosis, glycogen loss, fibrosis, and a minor vascularization in the liver. In contrast, hypothyroidism increased the proliferation of hepatocytes and the infiltration of mast cells, but did not modify the number of immune cells into sinusoids. These changes were associated with a minor anti-FXRα immunoreactivity of periportal hepatocytes and pericentral immune cells. Our results suggest that hypothyroidism induces a moderate non-alcoholic steatohepatitis, alllowing the hepatic regeneration. The FXRα may be involved in the development of non-alcoholic steatohepatitis in hypothyroid subjects., (© Georg Thieme Verlag KG Stuttgart · New York.)

Aim: To evaluate the morphometry and thyroid-hormone receptor (TR) expression in pelvic (pubococcygeus, Pcm) and perineal (bulbospongiosus, Bsm) muscles of control and hypothyroid female rabbits., Methods: Hypothyroidism was induced administering 0.02% methimazole in the drinking water for one month. Hematoxylin-eosin stained muscle sections were used to evaluate the fiber cross-sectional area (CSA) and the number of peripheral myonuclei per fiber. Immunohistochemistry was used to calculate the proportion of TR immunoreactive nuclei per fiber. Significant differences were considered at a P ≤ 0.05., Results: As compared to control rabbits, hypothyroidism increased the averaged fiber CSA and the myonuclei per fiber in the Bsm. Although the myonuclei number per fiber was also increased in the Pcm, the effect concerning the fiber CSA was only observed in a fraction of the Pcm fibers. Both TRα and TRβ were similarly expressed in the Pcm and Bsm. Hypothyroidism increased the expression of the TRα in the Bsm. Meanwhile, the expression of TR isoforms in the Pcm was not altered., Conclusion: Our findings support that the TR signaling is directly involved in morphometrical changes induced by hypothyroidism in the Pcm and Bsm. The effect of hypothyroidism on the Pcm and Bsm could be related to the different type of fiber and metabolism that these muscles have. Neurourol. Urodynam. 35:895-901, 2016. © 2015 Wiley Periodicals, Inc., (© 2015 Wiley Periodicals, Inc.)

Oviductal regions show particular histological characteristics and functions. Tubal pathologies and hypothyroidism are related to primary and secondary infertility. The impact of hypothyroidism on the histological characteristics of oviductal regions has been scarcely studied. Our aim was to analyse the histological characteristics of oviductal regions in control and hypothyroid rabbits. Hypothyroidism was induced by oral administration of methimazole (MMI) for 30 days. For both groups, serum concentrations of thyroid and gonadal hormones were determined. Sections of oviductal regions were stained with the Masson's trichrome technique to analyse both epithelial and smooth muscle layers. The percentage of proliferative epithelial cells (anti-Ki67) in diverse oviductal regions was also quantified. Data were compared with Student t-test, Mann-Whitney U-test, or Fischer's test. In comparison with the control group, the hypothyroid group showed: (i) a low concentration of T3 and T4, but a high level of TSH; (ii) similar values of serum estradiol, progesterone and testosterone; (iii) a large size of ciliated cells in the ampulla (AMP), isthmus (IST) and utero-tubal junction (UTJ); (iv) a large size of secretory cells in the IST region; (v) a low percentage of proliferative secretory cells in the fimbria-infundibulum (FIM-INF) region; and (vi) a similar thickness of the smooth muscle layer and the cross-sectional area in the AMP and IST regions. Modifications in the size of the oviductal epithelium in hypothyroid rabbits could be related to changes in the cell metabolism that may impact on the reproductive functions achieved by oviduct., (© 2014 Blackwell Verlag GmbH.)