Neonatal handling and reproductive function in female rats
Neonatal handling and reproductive function in female rats
复制标题
DOI：
10.1677/joe.1.05907
复制
发表时间：
2005-02-01
影响因子：
4
通讯作者：
Lucion, AB
中科院分区：
文献类型：
--
作者：
Gomes, CM;Raineki, C;Lucion, AB
新生儿处理诱导无排卵性发情周期和降低雌性大鼠的性接受性。雌性大鼠生殖腺（雌二醇（E-2）和孕酮(P)）、垂体（促黄体生成素（LH）和促卵泡生成素（FSH））和下丘脑（LH释放激素（LHPH））的同步分泌对生殖功能至关重要。本研究旨在描述初生处理大鼠整个发情周期血浆E2、P水平和发情前下午LH、FSH、催乳素（PRL）水平，以及发情前内侧视前区（MPOA）、中突区（ME）和内侧间隔区（MSA） LHRH含量。Wistar幼鼠在分娩后10天内被处理1分钟（新生儿处理组）或不受干扰（未处理组）。当他们成年后，通过颈静脉插管采集血样，显微解剖MPOA、ME和MSA。采用RIA法测定血浆激素水平和LHRH含量。经处理的大鼠发情当天早晨卵母细胞计数明显低于未经处理的大鼠。新生儿处理仅在发情前期降低E-2水平，而P水平在发情期和发情期降低。处理过的雌性在发情前的下午也表现出血浆LH、FSH和PRL水平的降低。MPOA中LHRH含量显著高于未处理组。孕前期E-2、LH、FSH和LHRH的分泌减少可能解释了新生处理大鼠的无排卵性发情周期。发情期PRL分泌减少可能与被处理过的雌性的性接受能力下降有关。综上所述，早期环境刺激可对下丘脑-垂体-性腺轴产生持久的影响。
Neonatal handling induces anovulatory estrous cycles and decreases sexual receptivity in female rats. The synchronous secretion of hormones from the gonads (estradiol (E-2) and progesterone (P)), pituitary (luteinizing (LH) and follicle-stimulating (FSH) hormones) and hypothalamus (LH-releasing hormone (LHPH)) are essential for the reproductive functions in female rats. The present study aimed to describe the plasma levels of E2 and P throughout the estrous cycle and LH, FSH and prolactin (PRL) in the afternoon of the proestrus, and the LHRH content in the medial preoptic area (MPOA), median eminence (ME) and medial septal area (MSA) in the proestrus, in the neonatal handled rats. Wistar pup rats were handled for 1 min during the first 10 days after delivery (neonatal handled group) or left undisturbed (nonhandled group). When they reached adulthood, blood samples were collected through a jugular cannula and the MPOA, ME and MSA were microdissected. Plasma levels of the hormones and the content of LHRH were determined by RIA. The number of oocytes counted in the morning of the estrus day in the handled rats was significantly lower than in the nonhandled ones. Neonatal handling reduces E-2 levels only on the proestrus day while P levels decreased in metestrus and estrus. Handled females also showed reduced plasma levels of LH, FSH and PRL in the afternoon of the proestrus. The LHRH content in the MPOA was significantly higher than in the nonhandled group. The reduced secretion of E-2, LH, FSH and LHRH on the proestrus day may explain the anovulatory estrous cycle in neonatal handled rats. The reduced secretion of PRL in the proestrus may be related to the decreased sexual receptiveness in handled females. In conclusion, early-life environmental stimulation can induce long-lasting effects on the hypothalamus-pituitary-gonad axis.