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神经紧张素(Neurotensin简称NT)是一种十三肽,首先在牛的下丘脑中发现。大部分的NT存在于特殊类型的腺细胞中,此类细胞分布在回肠粘膜较多,空肠内数量减少,而十二指肠、胃、胰和结肠则更少。当静脉注入的NT剂量使血浆神经紧张素样活性(p-NTLI)水平为微微克分子(pM)范围时,其作用主要限于胃肠道和脂肪组织,表现为抑制胃酸分泌、降低食管下段括约肌的张力,使胃和小肠内的食糜通过减慢。在浓度不影响血压和骨骼肌血流时,NT可使犬和人体皮下脂肪组织的血管收缩;高浓度时可降低血压,升高血糖。NT可能与调节餐后胃肠道的功能和脂肪组织内
Neurotensin (NT for short) is a tripeptide, first found in the hypothalamus of cattle. Most of the NT is present in specific types of glandular cells, which are distributed in more ileal mucosa, with a reduced number in the jejunum and fewer in the duodenum, stomach, pancreas, and colon. When the intravenous dose of NT makes plasma neurotensin-like activity (p-NTLI) in the picomolar range, its effects are mainly limited to the gastrointestinal tract and adipose tissue, which is manifested as inhibiting gastric acid secretion and lowering the lower esophageal sphincter. The tension causes the stomach and the food in the small intestine to slow down. When the concentration does not affect blood pressure and skeletal muscle blood flow, NT can make the blood vessels of the subcutaneous adipose tissue in dogs and humans contract; at high concentrations, it can lower blood pressure and increase blood sugar. NT may be related to the regulation of postprandial gastrointestinal function and adipose tissue