过刊浏览

哺乳、哺乳--禁乳及哺乳--禁乳后再哺乳对大鼠下丘脑胖素A免疫反应神经元的影响

孙桂荣, 田字彬, 曹永献, 樋口隆

青岛大学医学院附属医院分子生物学实验中心.山东,青岛 266003；青岛大学医学院附属医院内科.山东,青岛 266003；福井大学医学部生理学教室.福井市,910-1193

摘要

为观察下丘脑胖素A在哺乳期摄食增加和能量代谢中的作用,该研究采用脑连续切片之免疫组织化学和图像定量分析技术对分娩后d12非哺乳、持续哺乳、持续哺乳后禁哺乳过夜和持续哺乳--禁哺乳后再急性哺乳大鼠下丘脑胖素A免疫反应神经元的免疫反应性进行了观察和半定量分析。结果表明,分娩后持续哺乳11d,大鼠的日摄食量较同期分娩的非哺乳大鼠明显增加(180%),一夜禁哺乳则明显降低哺乳大鼠的日摄食量(--45%);哺乳12d,大鼠下丘脑胖素A免疫反应神经元的数目和平均染色强度较非哺乳大鼠明显增加({sl P}<0.001,{sl P}<0.05);禁哺乳过夜(15 h)明显降低哺乳大鼠胖素A免疫反应神经元的数目和平均染色强度({sl P}<0.001,{sl P}<0.05),与非哺乳大鼠比较无明显差异;禁哺乳过夜后再急性哺乳2小时明显增加禁哺乳大鼠胖素A免疫反应神经元的数目和平均染色强度({sl P}<0.001,{sl P}<0.05),急性哺乳5小时后,虽亦明显增加禁哺乳大鼠胖素A免疫反应性({sl P<0.05),但与急性哺乳2小时比较作用减弱。上述结果表明,持续哺乳和禁乳后再哺乳均导致下丘脑胖素A明显增加,提示哺乳期胖素A可能表达上调并可能与哺乳期摄食增加有关,且吸乳动作与下丘脑胖素A样神经元之间可能存在某种神经或体液性联系途径。

关键词： 神经生物学; 下丘脑; 胖素A; 免疫组织化学; 图像分析; 哺乳

Effects of lactation, lactation-cessation and lactation--cessation--lactation paradigms on hypothalamic orexin--A immunoreactive neurons in rats

Sun Guirong, Tian Zibin, Cao Yongxian, Higuchi T

Clinical Immunologic Center,the Affiliated Hospital of Medical College,Qingdao University.Qingdao 266003,Shandong；China；Department of Physiology,Medical Faculty,Fukui University.Fukui 910-1193,Japan

Abstract

Orexin-A is a novel neuropeptide produced by neurons mainly located in lateral hypothalamic area that potently facilitates appetite and food intake. The purpose of this study was to investigate the possible change in orexin-A immunoreactivity in suckling-induced hyperphagia. By using immunohistochemistry and image analysis techniques we examined orexin-A-like immunoreactivity in a series of rat brain sections corresponding to the hypothalamus in groups of non-lactating, lactating, lactating with overnight cessation of suckling, lactating and cessation followed by resumed short-term sucklings. Long-term lactation significantly increased daily food intake on day 3 (81%) and day 11 (180%) post partum compared to that in non-lactating postpartum rats, whereas daily food intake was significantly decreased by overnight cessation of suckling on day 11 post partum in long-term lactating rats (-45%). Moreover, long-term lactating rats on day 12 post partum exhibited significantly greater number and higher mean staining intensity of orexin-A immunoreactive neurons than those of non-suckling postpartum rats（P<0.001 and P<0.05 respectively）. Overnight cessation of lactation in rats on day 12 postpartum significantly decreased both the number and mean staining intensity of orexin-A immunoreactive neurons compared to those in long-term lactating group of rats（P<0.001 and P<0.05 respectively）, similar to the levels in the non-lactating postpartum rats. Resumed lactation for 2 and 5 hours after overnight cessation of lactation significantly increased the number （P<0.001 and P<0.05 respectively） and mean staining intensity （P<0.05） of orexin-A immunoreactive neurons compared to those in the rats without resumed lactation. Both long-term lactation and short-term resumed suckling enhanced orexin-A immunoreactivity in the hypothalamus in rats, and overnight cessation of lactation down-regulated the increased orexin-A immunoreactivity induced by long-term lactation. Suckling may regulate orexin-A expression in the hypothalamus and the increased orexin-A may be involved in hyperphagia seen in lactating rats, possibly suggesting the existence of some neural-humoral links between suckling and hypothalamic orexin-A-immunoreactive neurons.

Key words: neurobiology;Hypothalamus;orexin-A;Immunohistochemistry;image analysis;lactation

收稿日期：　　录用日期：

通讯作者：　　E-mail:

引用本文：

孙桂荣, 田字彬, 曹永献, 樋口隆. 哺乳、哺乳--禁乳及哺乳--禁乳后再哺乳对大鼠下丘脑胖素A免疫反应神经元的影响[J]. 生理学报 2004; 56 (6): .

Sun Guirong, Tian Zibin, Cao Yongxian, Higuchi T. Effects of lactation, lactation-cessation and lactation--cessation--lactation paradigms on hypothalamic orexin--A immunoreactive neurons in rats. Acta Physiol Sin 2004; 56 (6): (in Chinese with English abstract).