Hammer V A, Gietzen D W, Beverly J L, Rogers Q R
Department of Physiological Sciences, School of Veterinary Medicine, University of California, Davis 95616.
Am J Physiol. 1990 Sep;259(3 Pt 2):R627-36. doi: 10.1152/ajpregu.1990.259.3.R627.
The role of serotonin3 (5-HT3) receptors in the initial food intake depression of rats ingesting amino acid imbalanced or high-protein diets was investigated. The 5-HT antagonists metergoline, pirenpirone, ICS 205-930, and MDL 72222, the dopamine antagonist pimozide, or the alpha-adrenergic antagonist phentolamine were injected 15-45 min before presentation of test diets. Food intake was measured at intervals for 3 days. The 5-HT3 antagonists, ICS 205-930 and MDL 72222, restored feeding of a mild isoleucine (Ile)-imbalanced diet to control levels, although MDL 72222 had a longer time course of action. ICS 205-930 also increased intake of a severe Ile-imbalanced diet and Thr-imbalanced diet but not a high-protein (44% casein) diet. Treatment with metergoline, which blocks 5-HT1, 5-HT2, and dopamine receptor sites but not 5-HT3 sites, increased intake of the basal diet at 3 and 6 h but did not significantly alter intake of the mild Ile-imbalanced diet. Although pimozide tended to increase intake of the mild imbalanced diet, neither dopamine nor alpha-adrenergic receptor antagonism significantly affected imbalanced diet intake. Thus 5-HT3 receptors may mediate the anorexigenic activity of 5-HT associated with feeding an amino acid-imbalanced diet.
研究了5-羟色胺3（5-HT3）受体在摄入氨基酸不平衡或高蛋白饮食的大鼠初始食物摄入量降低中的作用。在给予试验饮食前15 - 45分钟注射5-HT拮抗剂美替拉林、哌仑西平、ICS 205-930和MDL 72222、多巴胺拮抗剂匹莫齐特或α-肾上腺素能拮抗剂酚妥拉明。每隔一段时间测量3天的食物摄入量。5-HT3拮抗剂ICS 205-930和MDL 72222将轻度异亮氨酸（Ile）不平衡饮食的进食量恢复到对照水平，尽管MDL 72222的作用时间更长。ICS 205-930还增加了重度Ile不平衡饮食和苏氨酸（Thr）不平衡饮食的摄入量，但未增加高蛋白（44%酪蛋白）饮食的摄入量。美替拉林可阻断5-HT1、5-HT2和多巴胺受体位点，但不阻断5-HT3位点，其治疗在3小时和6小时时增加了基础饮食的摄入量，但未显著改变轻度Ile不平衡饮食的摄入量。尽管匹莫齐特倾向于增加轻度不平衡饮食的摄入量，但多巴胺或α-肾上腺素能受体拮抗作用均未显著影响不平衡饮食的摄入量。因此，5-HT3受体可能介导了与摄入氨基酸不平衡饮食相关的5-HT的厌食活性。
