Translational Research Center for Gastrointestinal Disorders, Department of Clinical & Experimental Medicine, University of Leuven, Leuven, Belgium.
Abdominal Transplant Surgery, University Hospital Gasthuisberg, Leuven, Belgium.
Mol Nutr Food Res. 2018 Mar;62(5). doi: 10.1002/mnfr.201700804. Epub 2018 Feb 12.
The satiation properties of proteins involve effects on gut peptide release and gastrointestinal motility which may be altered during obesity. This study compares the in vitro response and role of amino acid (AA) taste receptors (TASR) in the effect of AAs and a casein hydrolysate on ghrelin release and smooth muscle (SM) contractions in the proximal gut of lean and obese patients.
Basal ghrelin release, measured from mucosal segments, is maximal in the fundus and decreased distally. Obesity selectively impaires the stimulatory effect of a casein hydrolyaste on ghrelin release in the fundus but does not affect its inhibitory effect in the small intestine (SI). The SM contractions induced by a casein hydrolysate and AAs are stronger in strips from the SI than from the fundus but are reduced in the stomach of obese patients. The region-dependent expression of AA-TASRs in the mucosa and SM layer is affected by obesity. Most of the AA-induced responses are reduced by the umami antagonist, lactisole. l-Met-induced responses involve bitter taste receptors.
Region-specific targeting of AA taste receptors on both enteroendocrine and SM cells with specific AA-enriched diets might be a useful strategy to combat obesity as well as hypomotility disorders.
蛋白质的饱腹感特性涉及对肠道肽释放和胃肠动力的影响，而这些在肥胖期间可能会发生改变。本研究比较了氨基酸（AA）味觉受体（TASR）在 AA 和酪蛋白水解物对瘦素和肥胖患者近端肠道胃泌素释放和平滑肌（SM）收缩的体外反应和作用。
从黏膜段测量的基础胃泌素释放在胃底最大，并向远端逐渐减少。肥胖选择性地损害了酪蛋白水解物对胃底胃泌素释放的刺激作用，但不影响其对小肠（SI）的抑制作用。酪蛋白水解物和 AA 诱导的 SM 收缩在来自 SI 的条带中比来自胃底的条带更强，但在肥胖患者的胃中减少。黏膜和 SM 层中 AA-TASR 的区域依赖性表达受肥胖影响。鲜味拮抗剂乳杆菌素降低了大部分 AA 诱导的反应。l-Met 诱导的反应涉及苦味味觉受体。
用富含特定 AA 的饮食对肠内分泌细胞和 SM 细胞上的 AA 味觉受体进行特定的区域靶向，可能是对抗肥胖和低动力障碍的有效策略。
