Riesselmann A, Baron A, Fregly M J, Cade J R
Department of Physiology, University of Florida College of Medicine, Gainesville.
Pharmacology. 1991;42(6):349-60. doi: 10.1159/000138818.
This study was designed to assess the effect of chronic dietary administration (2.5 and 5.0% by weight) of the neutral amino acid, L-tryptophan, on the development of hypertension during chronic exposure to cold. In addition, a warm-adapted and cold-treated control group receiving unsupplemented food were used. Chronic administration of the lower dose of L-tryptophan (850 mg/day) prevented the elevation of blood pressure attenuated cardiac hypertrophy, and had no effect on body weight during exposure to cold. The higher dose of L-tryptophan (1,690 mg/day) attenuated the rate of blood pressure increase, did not affect cardiac hypertrophy, attenuated the gain in body weight, and increased the urinary output of epinephrine. Thus, this dose may be associated with some toxicity. Both doses of tryptophan failed to prevent certain other responses characteristically occurring during exposure to cold: i.e. increased weight of the kidneys, adrenal glands and brown adipose tissue; increased food and water consumption; increased dipsogenic responsiveness to angiotensin II, and increased plasma aldosterone concentration. The results indicate that chronic dietary administration of L-tryptophan (850 mg/day) can prevent the development of cold-induced hypertension, as it can in all other models of hypertension tested thus far in rats.
本研究旨在评估长期饮食给予（按重量计2.5%和5.0%）中性氨基酸L-色氨酸对长期暴露于寒冷环境中高血压发展的影响。此外，还设立了一个接受未添加L-色氨酸食物的适应温暖环境并经寒冷处理的对照组。长期给予较低剂量的L-色氨酸（850毫克/天）可预防血压升高，减轻心脏肥大，且在暴露于寒冷环境期间对体重无影响。较高剂量的L-色氨酸（1690毫克/天）减缓了血压升高速率，不影响心脏肥大，减轻了体重增加，并增加了肾上腺素的尿量排泄。因此，该剂量可能具有一定毒性。两种剂量的色氨酸均未能预防在暴露于寒冷环境期间典型出现的某些其他反应，即肾脏、肾上腺和棕色脂肪组织重量增加；食物和水消耗增加；对血管紧张素II的致渴反应性增加，以及血浆醛固酮浓度增加。结果表明，长期饮食给予L-色氨酸（850毫克/天）可预防寒冷诱导的高血压的发展，就像在迄今为止在大鼠中测试的所有其他高血压模型中一样。
