我们先前表明,短期甲状腺功能减退和甲状腺功能亢进会引起雄性大鼠离散大脑区域神经肽谷氨酸-异亮氨酸-酰胺(NEI)浓度的变化。探讨甲状腺功能减退症和甲状腺功能亢进对主要与生殖和行为相关的下丘脑区NEI浓度的可能影响。雌性大鼠在发情周期的不同天处死。循环黄体生成素(LH),在对照组中测量雌二醇和孕酮浓度,甲状腺功能减退(T低,在7-9天内接受PTU治疗)和甲状腺功能亢进(hyperT,4-7天期间的l-T4)动物。两种治疗均减弱了LH激增。甲状腺功能减退和甲状腺功能亢进在发情期下午(P-PM)期间增加雌二醇浓度,尽管在发情早晨(P-AM)期间,hypoT大鼠与对照组相比显示出较低的值。在动情期早晨(D2)的P-PM和hyperT中,所有组的孕酮水平均较高。在发情周期中,除下丘脑外侧部(PLH)的发情期(E)外,hypoT大鼠的NEI浓度较低。在P-PM期间,在下丘脑外侧孔周围部分(PeFLH)的两种治疗方法也使它们减少。甲状腺功能减退症在P-PM期间导致终层和前脑室周围核(OVLTAVPV)的器官血管中的NEI浓度较高。目前的结果表明,NEI浓度在不同的研究区域受到甲状腺功能减退和甲状腺功能亢进的复杂调节,表明NEI值与发情周期中性腺类固醇水平变化之间存在相关性。这些变化可能是,在某种程度上,负责在这些病理中观察到的下丘脑-垂体-性腺轴的改变。
We previously showed that short-term hypo- and hyperthyroidism induce changes in neuropeptide glutamic-acid-isoleucine-amide (
NEI) concentrations in discrete brain areas in male rats. To investigate the possible effects of hypo- and hyperthyroidism on
NEI concentrations mainly in hypothalamic areas related to reproduction and behavior, female rats were sacrificed at different days of the estrous cycle. Circulating luteinizing hormone (LH), estradiol and progesterone concentrations were measured in control, hypothyroid (hypoT, treated with PTU during 7-9 days) and hyperthyroid (hyperT, l-T4 during 4-7 days) animals. Both treatments blunted the LH surge. Hypo- and hyperthyroidism increased estradiol concentrations during proestrus afternoon (P-PM), although hypoT rats showed lower values compared to control during proestrus morning (P-AM). Progesterone levels were higher in all groups at P-PM and in the hyperT during diestrus morning (D2).
NEI concentrations were lower in hypoT rats during the estrous cycle except in estrus (E) in the peduncular part of the lateral hypothalamus (PLH). They were also reduced by both treatments in the perifornical part of the lateral hypothalamus (PeFLH) during P-PM. Hypothyroidism led to higher
NEI concentrations during P-PM in the organum vasculosum of the lamina terminalis and anteroventral periventricular nucleus (OVLT+AVPV). The present results indicate that NEI concentration is regulated in a complex manner by hypo- and hyperthyroidism in the different areas studied, suggesting a correlation between
NEI values and the variations of gonadal steroid levels during estrous cycle. These changes could be, in part, responsible for the alterations observed in the hypothalamic-pituitary-gonadal axis in these pathologies.