Sun Jianran, Hui Cancan, Xia Tongjia, Xu Min, Deng Datong, Pan Faming, Wang Youmin
Department of Endocrinology, Institute of Endocrinology and Metabolism, The First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei, 230022, Anhui, China.
Department of Epidemiology and Biostatistics,School of Public Health, Anhui Medical University,81Meishan Road, Hefei, 230032, Anhui, China.
BMC Endocr Disord. 2018 May 24;18(1):30. doi: 10.1186/s12902-018-0258-y.
This 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.
Female 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.
The abortion rate differed significantly between the hypothyroidism pregnancy group and the normal pregnancy group (P < 0.05). No significant differences were found in the distribution of the GnRHR among the five nuclei (hypothalamic arcuate nucleus, hypothalamic ventromedial nucleus, hypothalamic anterior nucleus, paraventricular nucleus of the hypothalamus, and ventral premammillary nucleus) of the hypothalamus and ovary (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).
Hypothyroidism 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.
本研究旨在检测甲状腺功能减退的斯普拉格-道利（SD）大鼠下丘脑-垂体-卵巢轴激素水平的变化，并确定成年雌性大鼠妊娠率和流产率的差异。还研究了促性腺激素释放激素（GnRH）作为下丘脑-垂体-卵巢轴与甲状腺激素调节的生殖功能之间联系的潜在作用。
将136只雌性SD大鼠随机分为两组：正常饮水组（n = 60）和0.05%丙硫氧嘧啶饮水组（PTU 2 mg/kg/天，n = 76），以建立成年大鼠甲状腺功能减退模型（6周）。以1:2的雌雄比例建立甲状腺功能减退妊娠模型。分别采用实时定量PCR（qRT-PCR）和免疫组化检测大鼠GnRH mRNA和GnRH受体（GnRHR）的表达。
甲状腺功能减退妊娠组与正常妊娠组的流产率差异有统计学意义（P < 0.05）。下丘脑和卵巢的五个核（下丘脑弓状核、下丘脑腹内侧核、下丘脑前核、下丘脑室旁核和乳头体前腹侧核）中GnRHR的分布无显著差异（P > 0.05）。甲状腺功能减退对四组（正常对照组、正常妊娠组、甲状腺功能减退妊娠组和甲状腺功能减退组）下丘脑-垂体-卵巢轴中GnRH mRNA表达无显著影响（P > 0.05）。
甲状腺功能减退对大鼠妊娠有不良影响，可能影响垂体GnRHR的分布，而对下丘脑和卵巢核中GnRHR的分布无明显影响。甲状腺功能减退对GnRH mRNA表达无影响。
