Effect of hypothyroidism on the hypothalamic-pituitary-ovarian axis and reproductive function of pregnant rats.

ABSTRACT: BACKGROUNDThis study aimed to detect changes in hormone levels in the hypothalamic-pituitary-ovarian axis in Sprague-Dawley (SD) rats with hypothyroidism, and identify differences in the pregnancy and abortion rates of female adult rats. The potential role of gonadotropin releasing hormone (GnRH) as the link between the hypothalamic-pituitary-ovarian axis and reproductive function regulated by thyroid hormones was also investigated.METHODSFemale SD rats (n?=?136) were causally classified into two groups: the normal-drinking-water group (n?=?60) and the 0.05% propylthiouracil-drinking-water group (PTU 2 mg/kg/day, n?=?76) to establish an adult rat model of hypothyroidism (6 weeks). Female and male rats at a ratio of 1:2 were used to establish a hypothyroidism pregnancy model. GnRH mRNA and GnRH receptor (GnRHR) expression in rats was detected using real time quantitative PCR(qRT-PCR) and immunohistochemistry, respectively.RESULTSThe abortion rate differed significantly between the hypothyroidism pregnancy group and the normal pregnancy group (P??0.05). Hypothyroidism had no significant effect on GnRH mRNA expression in the hypothalamic-pituitary-ovarian axis in the four groups (normal control group, normal pregnancy group, hypothyroidism pregnancy group, and hypothyroidism group) (P?>?0.05).CONCLUSIONSHypothyroidism had an adverse impact on pregnancy in rats and may affect the distribution of pituitary GnRHR, whereas it did not obviously affect the distribution of GnRHR in the nuclei of the hypothalamus and ovary. Hypothyroidism had no effect on GnRH mRNA expression.

SUBMITTER: Sun J 

PROVIDER: S-EPMC5968710 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature