Calonge M L, Ilundáin A, Bolufer J
Departamento de Fisiologia y Biologia Animal, Facultad de Farmacia, Seville, Spain.
Am J Physiol. 1990 May;258(5 Pt 1):G660-4. doi: 10.1152/ajpgi.1990.258.5.G660.
The transport of glycylsarcosine (Gly-Sar) has been investigated in cells isolated from the proximal cecum and rectum of the chick, and their characteristics have been compared with those of the jejunal dipeptide transport system. Results show that 1) cecal and rectal cells are capable of actively accumulating Gly-Sar. 2) Gly-Sar initial uptake and steady-state accumulation in cecal and rectal cells were decreased in Na(+)-free mannitol-substituted medium. However, in both cell types, as in jejunal cells, intracellular accumulations higher than one can be observed in the absence of Na+. 3) By lowering the medium pH from 7.4 to 6.0, the Gly-Sar accumulation was stimulated in both cecal and rectal cells. 4) Addition of 1 mM amiloride inhibited Gly-Sar uptake by the cecal and rectal cells. We conclude that proximal cecum and rectum have a dipeptide transport system with properties similar to those found in the jejunum.
已对从雏鸡近端盲肠和直肠分离出的细胞中甘氨酰肌氨酸（Gly-Sar）的转运进行了研究，并将其特性与空肠二肽转运系统的特性进行了比较。结果表明：1）盲肠和直肠细胞能够主动积累Gly-Sar。2）在无钠甘露醇替代培养基中，盲肠和直肠细胞中Gly-Sar的初始摄取和稳态积累减少。然而，在这两种细胞类型中，与空肠细胞一样，在无钠的情况下可观察到细胞内积累高于1。3）通过将培养基pH从7.4降至6.0，盲肠和直肠细胞中的Gly-Sar积累均受到刺激。4）添加1 mM氨氯吡脒可抑制盲肠和直肠细胞对Gly-Sar的摄取。我们得出结论，近端盲肠和直肠具有与空肠中发现的性质相似的二肽转运系统。
