Robert J J, Orosco M, Rouch C, Cohen Y, Jacquot C
Laboratoire de Pharmacologie, U.A.-CNRS 594, Faculté de Pharmacie, Châtenay-Malabry, France.
Brain Res. 1990 Feb 26;510(1):7-11. doi: 10.1016/0006-8993(90)90720-v.
The Leu-enkephalin analogue D-Ser2-Leu-Enk-Thr6 (DSLET) had been shown to enhance feeding in rats, increase dopaminergic activity in the striatum like other opiate agonists, and particularly to decrease dopaminergic activity in the hypothalamus. In this study, the latter effect was found to be localized in the hypothalamic nuclei involved in the regulation of feeding such as the paraventricular (PVN), ventromedian (VMH), dorsomedian (DMH) nuclei and the lateral hypothalamus (LH). DSLET produced the same decrease in dopaminergic activity in the LH as in the whole hypothalamus. In the median nuclei (PVN and VMH and to a lesser extent in the DMH), an opposite effect was observed, resembling that in the striatum. The relevance of these opposite variations with regard to the feeding effect of DSLET is discussed. The decreased dopaminergic activity in the LH would appear to be the most specifically related to the behavioural effect given the known role of dopamine in this region. These data reconcile apparently contradictory aspects of the role of dopamine and the functional opposition between the lateral and median hypothalamus in food intake control.
亮氨酸脑啡肽类似物D-丝氨酸2-亮氨酸-脑啡肽-苏氨酸6（DSLET）已被证明可增强大鼠的进食量，与其他阿片类激动剂一样增加纹状体中的多巴胺能活性，尤其是降低下丘脑中的多巴胺能活性。在本研究中，发现后一种效应定位于参与进食调节的下丘脑核团，如室旁核（PVN）、腹内侧核（VMH）、背内侧核（DMH）和外侧下丘脑（LH）。DSLET在下丘脑外侧产生的多巴胺能活性降低与整个下丘脑的情况相同。在中间核团（室旁核和腹内侧核，背内侧核的程度较轻）中，观察到相反的效应，类似于纹状体中的效应。讨论了这些相反变化与DSLET进食效应的相关性。鉴于多巴胺在该区域的已知作用，下丘脑外侧多巴胺能活性的降低似乎与行为效应最具特异性相关。这些数据调和了多巴胺作用以及下丘脑外侧和中间部分在食物摄入控制中的功能对立方面明显相互矛盾的情况。
