Beverly J L, Gietzen D W, Rogers Q R
Department of Physiological Sciences, School of Veterinary Medicine, Davis, CA 95616.
J Nutr. 1991 May;121(5):754-61. doi: 10.1093/jn/121.5.754.
The effect of inhibiting protein synthesis within the prepyriform cortex (PPC) on intake of an amino acid imbalanced diet was evaluated in rats receiving bilateral injections of the dietary limiting amino acid (DLAA). Injection of the DLAA into the PPC increased intake of the imbalanced diet by 150% and incorporation of [3H]leucine into the trichloroacetic acid insoluble fraction of PPC homogenates by 248%. Coinjection of puromycin (100 mumol/L) or actinomycin D (10 mumol/L) blocked the increase in intake of the imbalanced diet but had no effect on intake of the basal diet. Puromycin blocked the increase in intake of the imbalanced diet whether injected with the DLAA or 6 h later. Selection of the imbalanced diet over a protein-free diet when the DLAA was administered was blocked by co-injecting puromycin or actinomycin D. The results indicated that the increased intake and the reversal of aversion to the imbalanced diet when the DLAA was injected into the PPC required de novo protein synthesis. The proteins necessary for the feeding response seemed to have a short half-life and seemed to require synthesis of new mRNA. We conclude that changes in concentration of the DLAA within the PPC influenced protein synthesis at the genomic level.
在接受双侧注射膳食限制氨基酸（DLAA）的大鼠中，评估了抑制梨状前皮质（PPC）内蛋白质合成对氨基酸失衡饮食摄入量的影响。向PPC注射DLAA使失衡饮食的摄入量增加了150%，并使[3H]亮氨酸掺入PPC匀浆的三氯乙酸不溶性部分的量增加了248%。联合注射嘌呤霉素（100 μmol/L）或放线菌素D（10 μmol/L）可阻断失衡饮食摄入量的增加，但对基础饮食的摄入量没有影响。无论与DLAA同时注射还是在6小时后注射，嘌呤霉素均可阻断失衡饮食摄入量的增加。当给予DLAA时，联合注射嘌呤霉素或放线菌素D可阻断在无蛋白饮食之上选择失衡饮食的行为。结果表明，当向PPC注射DLAA时，摄入量的增加以及对失衡饮食厌恶的逆转需要从头合成蛋白质。进食反应所需的蛋白质似乎半衰期较短，并且似乎需要合成新的mRNA。我们得出结论，PPC内DLAA浓度的变化在基因组水平上影响蛋白质合成。
