کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5872371 | 1143092 | 2013 | 4 صفحه PDF | دانلود رایگان |
SummaryBackground & aimsThe ingestion by rats of different proteins causes large differences in the plasma ratio of tryptophan to other large neutral amino acids, which predicts brain tryptophan uptake and serotonin synthesis. We evaluated in humans whether ingesting these proteins also produces large excursions in the tryptophan ratio.MethodsFasting males (n = 6) ingested V-8 Juice containing 40 g of α-lactalbumin, gluten, zein or starch. Blood was drawn before and at 30 min intervals after ingestion for 4 h; tryptophan and other large neutral amino acids were quantitated.ResultsPre-meal plasma tryptophan was â¼50 nmol/ml; the tryptophan ratio was â¼0.010. α-Lactalbumin increased plasma tryptophan (3-fold) and the tryptophan ratio (50%); starch did not change either tryptophan variable, while gluten caused a modest (25%) and zein a large reduction (50%) in plasma tryptophan. Gluten and zein reduced the tryptophan ratio. The maximal difference in the tryptophan ratio occurred between α-lactalbumin and zein and was large (â¼3-fold).ConclusionSince the plasma tryptophan ratio predicts brain tryptophan uptake and serotonin synthesis in rats, the differences in the ratio produced in humans by these proteins may modify serotonin synthesis, and perhaps elicit serotonin-linked changes in behavior.
Journal: Clinical Nutrition - Volume 32, Issue 6, December 2013, Pages 1073-1076