Muscaritoli M, Meguid M M, Beverly J L, Yang Z J, Cangiano C, Rossi-Fanelli F
Department of Surgery, University Hospital, SUNY Health Science Center, Syracuse, NY 13210, USA.
J Surg Res. 1996 Feb 1;60(2):389-97. doi: 10.1006/jsre.1996.0064.
Whether in tumor-bearing rats a temporal relationship exists between an increase in plasma free tryptophan (FTRP), an increase in brain serotonin (5-HT), and onset of anorexia was studied. Rats were assigned to three groups: tumor-bearing (TB), pair fed (PF), and controls. Food intake was recorded daily. In TB rats anorexia developed on Day 18 and thereafter food intake decreased progressively until end of study. After tumor inoculation, tumor became palpable on Day 10 and continued to grow exponentially until end of study. Rats were killed on Days 6, 10, 16, 18, 22, and 26 to determine plasma FTRP, FTRP/LNAA, and brain 5HT and compared to PF and controls. On Day 6, before tumors became detectable, FTRP and FTRP/LNAA were increased (P < 0.05) in TB rats vs controls. Both continued to increase so that by Day 18 when food intake had started to decrease (P < 0.05), brain 5-HT increased and correlated with the onset of anorexia (R2 = 0.6, P < 0.05). Increases in plasma FTRP the precursor to brain 5-HT occurred in TB rats before physical appearance of tumor and increased until an increase in brain 5-HT occurred, leading to anorexia.
研究了荷瘤大鼠血浆游离色氨酸（FTRP）增加、脑血清素（5-HT）增加与厌食症发作之间是否存在时间关系。将大鼠分为三组：荷瘤组（TB）、配对喂食组（PF）和对照组。每天记录食物摄入量。在TB大鼠中，厌食症在第18天出现，此后食物摄入量逐渐减少直至研究结束。接种肿瘤后，肿瘤在第10天可触及，并持续呈指数生长直至研究结束。在第6、10、16、18、22和26天处死大鼠，以测定血浆FTRP、FTRP/LNAA和脑5-HT，并与PF组和对照组进行比较。在第6天，即在肿瘤可检测到之前，TB大鼠的FTRP和FTRP/LNAA较对照组增加（P<0.05）。两者均持续增加，以至于在第18天食物摄入量开始减少时（P<0.05），脑5-HT增加，并与厌食症发作相关（R2 = 0.6，P<0.05）。作为脑5-HT前体的血浆FTRP增加在TB大鼠肿瘤出现之前就已发生，并持续增加，直至脑5-HT增加导致厌食症。
