Choi Si Ho, Kwon Bum Sup, Lee Seoul, Houpt Thomas A, Lee Hoon Taek, Kim Dong Goo, Jahng Jeong Won
Department of Pharmacology and Yonsei Brain Research Institute, BK21 Project for Medical Science, Yonsei University College of Medicine, 120-752, Seoul, South Korea.
Regul Pept. 2003 Sep 15;115(2):73-80. doi: 10.1016/s0167-0115(03)00126-5.
This study was conducted to determine if serotonin (5-hydroxytryptamine; 5-HT) system correlates with the hypothalamic expression of cocaine-amphetamine-regulated transcript (CART) gene. Rats received intraperitoneal 5-hydroxy-L-tryptophan (5-HTP; a single or three daily injections at a dose of 100 mg/kg/10 ml), and CART mRNA level in the hypothalamus was examined by in situ hybridization at different time points. The 5-HT contents of the hypothalamus as well as the brainstem was increased persistently by 5-HTP injections, and food intake and body weight gain reduced. CART mRNA level decreased significantly in the hypothalamic arcuate nucleus by three daily 5-HTP, but not by a single injection. The pair-fed group of the chronic 5-HTP did not show a decrease in the arcuate CART mRNA level. The plasma leptin level markedly decreased in the chronic 5-HTP group, compared to the saline group, however, still higher than the pair-fed group with a statistical significance. These results suggest that 5-HT may suppress CART mRNA expression in the arcuate nucleus, not only by leptin signaling via its anorectic effect on the control of food intake, but also by some non-leptin mediated pathway.
本研究旨在确定血清素（5-羟色胺；5-HT）系统是否与下丘脑可卡因-苯丙胺调节转录物（CART）基因的表达相关。给大鼠腹腔注射5-羟-L-色氨酸（5-HTP；以100mg/kg/10ml的剂量每日注射一次或三次），并在不同时间点通过原位杂交检测下丘脑CART mRNA水平。注射5-HTP后，下丘脑以及脑干的5-HT含量持续增加，食物摄入量和体重增加减少。每日注射三次5-HTP可使下丘脑弓状核的CART mRNA水平显著降低，但单次注射则无此效果。慢性5-HTP处理的配对喂养组弓状核CART mRNA水平未降低。与生理盐水组相比，慢性5-HTP组血浆瘦素水平显著降低，但仍高于配对喂养组，具有统计学意义。这些结果表明，5-HT可能不仅通过其对食物摄入控制的厌食作用经由瘦素信号传导，还通过一些非瘦素介导的途径抑制弓状核中CART mRNA的表达。
