Flatt P R, Kwasowski P, Howland R J, Bailey C J
Biomedical Sciences Research Centre, University of Ulster, Coleraine, Northern Ireland.
J Nutr. 1991 Jul;121(7):1123-8. doi: 10.1093/jn/121.7.1123.
The effects of oral administration of eight L-amino acids (alanine, arginine, cysteine, glycine, histidine, hydroxyproline, lysine and threonine) individually or as an amino acid mixture on plasma gastric inhibitory polypeptide (GIP), insulin and glucose concentrations were examined in 18-h fasted obese hyperglycemic (ob/ob) mice. At a dose of 5.4 mmol/kg body weight, arginine, cysteine, histidine and the amino acid mixture were equipotent in terms of increasing plasma GIP and insulin concentrations. Alanine, hydroxyproline and lysine also increased plasma GIP, but insulin concentrations were unchanged. In contrast, threonine failed to affect either GIP or insulin concentrations. There was no correlation between either the incremental or integrated GIP and insulin responses, and none of the amino acids administered affected circulating glucose concentrations. The results indicate that a range of essential and nonessential neutral and basic amino acids stimulate the release of GIP in ob/ob mice. However, GIP made only a modest contribution to the stimulation of insulin secretion following administration of amino acids in the presence of basal glycemia.
在禁食18小时的肥胖高血糖（ob/ob）小鼠中，研究了单独口服八种L-氨基酸（丙氨酸、精氨酸、半胱氨酸、甘氨酸、组氨酸、羟脯氨酸、赖氨酸和苏氨酸）或作为氨基酸混合物口服对血浆胃抑制多肽（GIP）、胰岛素和葡萄糖浓度的影响。在剂量为5.4 mmol/kg体重时，精氨酸、半胱氨酸、组氨酸和氨基酸混合物在增加血浆GIP和胰岛素浓度方面具有同等效力。丙氨酸、羟脯氨酸和赖氨酸也增加了血浆GIP，但胰岛素浓度未改变。相比之下，苏氨酸未能影响GIP或胰岛素浓度。增量或累积的GIP与胰岛素反应之间均无相关性，且所给予的氨基酸均未影响循环葡萄糖浓度。结果表明，一系列必需和非必需的中性和碱性氨基酸可刺激ob/ob小鼠释放GIP。然而，在基础血糖存在的情况下，给予氨基酸后，GIP对胰岛素分泌的刺激作用仅为适度贡献。
