Quill H, Weiser M M
Gastroenterology. 1975 Aug;69(2):470-8.
Adenylate and guanylate cyclase activities were measured in rat small intestinal villus and crypt cells to determine possible correlations with cellular differentiation. Isolated intestinal cells were prepared by a method which effectively separates differentiated villus cells from undifferentiated crypt cells (J Biol Chem 248:2542, 1973). Crypt cells were found to have a significantly lower guanylate cyclase activity than villus cells. Adenylate cyclase activity was higher in crypt cells than villus cells, although the difference was less striking than the reverse gradient observed for guanylate cyclase. There was no gradient of activity for cyclic guanosine 3':5'-monophosphate phosphodiesterase. However, cyclic adenosine 3':5'-monophosphate phosphodiesterase activity was lower in villus cells. No villus to crypt gradient of cyclic adenosine 3':5'-monophosphate concentration was detected in mucosa frozen rapidly in liquid nitrogen. The properties and subcellular localization of the cyclases were also evaluated, and of particular interest was the localization of guanylate cyclase to the microvillus membrane and the confirmation of adenylate cyclase activity in the lateral-basal membrane. The villus to crypt gradient of guanylate cyclase suggests that this enzyme has a specialized role in the differentiated villus cell. The contrasting subcellular localization of the cyclases suggests that the cyclases may be interrelated, possibly reflecting the epithelial cell polarity for absorption and secretion.
测定大鼠小肠绒毛和隐窝细胞中的腺苷酸环化酶和鸟苷酸环化酶活性，以确定其与细胞分化的可能关联。采用一种能有效分离分化的绒毛细胞和未分化的隐窝细胞的方法制备分离的肠细胞（《生物化学杂志》248:2542, 1973）。发现隐窝细胞的鸟苷酸环化酶活性明显低于绒毛细胞。隐窝细胞中的腺苷酸环化酶活性高于绒毛细胞，尽管这种差异不如鸟苷酸环化酶观察到的反向梯度那么显著。环磷酸鸟苷3':5'-单磷酸磷酸二酯酶没有活性梯度。然而，环磷酸腺苷3':5'-单磷酸磷酸二酯酶活性在绒毛细胞中较低。在液氮中快速冷冻的黏膜中未检测到环磷酸腺苷浓度从绒毛到隐窝的梯度。还评估了环化酶的性质和亚细胞定位，特别值得关注的是鸟苷酸环化酶定位于微绒毛膜以及腺苷酸环化酶活性在侧基膜中的确认。鸟苷酸环化酶从绒毛到隐窝的梯度表明该酶在分化的绒毛细胞中具有特殊作用。环化酶不同的亚细胞定位表明它们可能相互关联，这可能反映了上皮细胞吸收和分泌的极性。
