Fitzpatrick L R, Wang P, Eikenburg B E, Haddox M K, Johnson L R
Am J Physiol. 1986 May;250(5 Pt 1):G709-13. doi: 10.1152/ajpgi.1986.250.5.G709.
Ornithine decarboxylase (ODC) activity has been found to be preferentially associated with small intestinal villus cells rather than crypt cells in the rat. In the present study, ODC, S-adenosylmethionine decarboxylase (SAMDC), and polyamines were measured in isolated enterocytes to determine which cell populations increased polyamine biosynthetic activity after refeeding. Two hours following refeeding, significant increases in ODC were observed in villus tip (10 times) and midvillus (20 times) enterocytes. No increase in ODC activity was found in isolated crypt cells. A similar pattern was observed for SAMDC. Enzyme activity increased in villus tip (2 times) and midvillus (27 times) cells but not in crypt enterocytes. Putrescine contents were increased following refeeding in midvillus enterocytes (P less than 0.05) and in crypt cells (P less than 0.05). The accumulation of putrescine in midvillus cells occurs via ODC-induced biosynthesis, whereas in crypt enterocytes it may be due to putrescine uptake. The lack of induction of ODC and SAMDC in crypt enterocytes following acute refeeding suggests these enzymes are apparently not involved in the initiation of cell proliferation known to occur under this condition.
已发现鸟氨酸脱羧酶（ODC）活性在大鼠中优先与小肠绒毛细胞而非隐窝细胞相关。在本研究中，对分离的肠上皮细胞中的ODC、S-腺苷甲硫氨酸脱羧酶（SAMDC）和多胺进行了测量，以确定在重新喂食后哪些细胞群体增加了多胺生物合成活性。重新喂食两小时后，在绒毛顶端（10倍）和绒毛中部（20倍）的肠上皮细胞中观察到ODC显著增加。在分离的隐窝细胞中未发现ODC活性增加。SAMDC也观察到类似的模式。酶活性在绒毛顶端（2倍）和绒毛中部（27倍）细胞中增加，但在隐窝肠上皮细胞中未增加。重新喂食后，绒毛中部肠上皮细胞（P<0.05）和隐窝细胞（P<0.05）中的腐胺含量增加。绒毛中部细胞中腐胺的积累是通过ODC诱导的生物合成发生的，而在隐窝肠上皮细胞中可能是由于腐胺的摄取。急性重新喂食后隐窝肠上皮细胞中ODC和SAMDC缺乏诱导表明这些酶显然不参与已知在此条件下发生的细胞增殖的起始。
