■生殖系统受到环境和生理信号的严格调节。褪黑激素,被称为黑暗激素,在调节哺乳动物的昼夜节律和生殖系统中起着至关重要的作用。甲状腺功能减退症是危害生殖系统的关键内分泌疾病。尽管许多关于褪黑素对生殖系统的影响的研究,关于甲状腺功能减退症中褪黑激素合成调节的信息相互矛盾。本研究的目的是研究一天中不同时间甲状腺功能减退症大鼠松果体和性腺中血浆褪黑素水平和Aanat和Asmt基因表达的调节。
■雌性和雄性Wistar大鼠分为对照组和甲状腺功能减退组。使用丙基硫氧嘧啶(PTU)诱导甲状腺功能减退15天,大鼠在亮灯后六小时安乐死(ZT6),关灯前(ZT11.5),和6小时后关灯(ZT18)。血浆中游离甲状腺素(FT4)和褪黑素定量,在松果体和性器官(睾丸和卵巢)中测量褪黑激素合成酶(Aanat和Asmt)的基因表达。此外,对性器官进行形态学分析.
■结果揭示了两性之间的一些差异。甲状腺功能减退症减少了卵巢的窦和初级卵泡,减少了睾丸的重量,附睾,还有前列腺.关于基因表达,我们观察到在光照期(ZT6)期间松果体中Aanat表达减少,在男性中,这种减少发生在黑暗阶段(ZT18)。关于Asmt表达式,在黑暗阶段(ZT18),女性也有所减少。在性腺里,ZT11.5时两性的表达均增加。此外,有趣的是观察性腺中FT4水平与Asmt表达之间的关联。
■这项研究表明,急性甲状腺功能减退症可以影响性腺中的褪黑能系统成分,特别是褪黑激素合成酶(Aanat和Asmt)的基因表达,有助于疾病进展过程中生殖器官的变化。这些发现增强了我们对甲状腺功能减退期间生殖系统褪黑素合成的理解,在雄性和雌性大鼠中表现出不同的反应,并提示甲状腺功能减退以性别依赖性方式影响褪黑素合成的昼夜节律。
UNASSIGNED: The reproductive system is tightly regulated by environmental and physiological signals. Melatonin, known as the hormone of darkness, plays a crucial role in regulating both the circadian and reproductive systems in mammals. Hypothyroidism is a key endocrine disorder that harms the reproductive system. Despite many studies on melatonin\'s effects on the reproductive system, there is conflicting information regarding melatonin synthesis modulation in hypothyroidism. The objective of this study was to investigate the modulation of plasma melatonin levels and gene expression of Aanat and Asmt in the pineal gland and gonads of rats with hypothyroidism at different times of the day.
UNASSIGNED: Female and male Wistar rats were divided into control and hypothyroid groups. Hypothyroidism was induced using propylthiouracil (PTU) for 15 days, rats were euthanized six hours after lights on (ZT6), before lights off (ZT11.5), and six hours after lights off (ZT18). Free thyroxine (FT4) and melatonin were quantified in plasma, and gene expressions of melatonin synthesizing enzymes (Aanat and Asmt) were measured in pineal and sexual organs (testis and ovary). Also, morphological analysis was performed in sexual organs.
UNASSIGNED: The results reveal some disparities between the sexes. Hypothyroidism reduced antral and primary follicles in the ovary, and reduced the weight of testis, epididymis, and prostate. In relation to gene expression, we observed a reduction in Aanat expression in the pineal gland during the light phase (ZT6), and in males, this reduction occurred during the dark phase (ZT18). Regarding Asmt expression, there was a decrease in females also during the dark phase (ZT18). In the gonads, there was an increase in expression in both sexes at ZT11.5. Additionally, it was interesting to observe the association between FT4 levels and Asmt expression in the gonads.
UNASSIGNED: This study showed that acute hypothyroidism can affect components of the melatonergic system in gonads, particularly gene expression of melatonin synthesis enzymes (Aanat and Asmt) contributing to changes in reproduction organs during disease progression. These findings enhance our understanding of melatonin synthesis in the reproductive system during hypothyroidism, showing distinct responses in male and female rats, and suggest that hypothyroidism affects the circadian rhythmicity of melatonin synthesis in a sex-dependent manner.