Ménard D, Dagenais P
Département d'Anatomie et de Biologie Cellulaire, Faculté de Médecine, Université de Sherbrooke, Canada.
Biol Neonate. 1993;63(5):310-5. doi: 10.1159/000243947.
The influence of insulin on the postnatal development of DNA synthesis and epithelial and muscular cell proliferation has been studied in suckling mice. Daily administration of insulin (12.5 mU/g body weight) during 3 days to 8-day-old mice induced a significant increase of the incorporation of [3H]-thymidine into DNA in the small intestine and the proximal and distal halves of the colon. The esophagus and the glandular portion of the stomach did not respond. A detailed analysis of the proximal and distal colon between 4 and 30 days revealed a decrease of [3H]-thymidine incorporation into total DNA during this period. However, the establishment of the labeling indices in specific compartments such as the epithelium and the muscularis externa revealed that the epithelial cellular proliferation increased around weaning period in both segments while a drastic reduction of cellular proliferation occurred in the muscle layer. A premature rise of the circulating insulin level induced a significant increase of the epithelial labeling indices in both colonic segments but remained without effects on the muscular layer. These results suggest an important role of insulin in the modulation of the ontogenic changes in epithelial cell proliferation of the mouse colon.
在乳鼠中研究了胰岛素对出生后DNA合成以及上皮和肌肉细胞增殖的影响。对3日龄至8日龄的小鼠每日注射胰岛素（12.5 mU/g体重），持续3天，结果显示小肠以及结肠近端和远端的[3H] - 胸腺嘧啶核苷掺入DNA的量显著增加。食管和胃的腺部没有反应。对4至30日龄的结肠近端和远端进行详细分析发现，在此期间[3H] - 胸腺嘧啶核苷掺入总DNA的量减少。然而，在特定区域如上皮和外肌层建立标记指数显示，两个节段的上皮细胞增殖在断奶期前后增加，而肌肉层的细胞增殖则急剧减少。循环胰岛素水平过早升高导致两个结肠节段的上皮标记指数显著增加，但对肌肉层没有影响。这些结果表明胰岛素在调节小鼠结肠上皮细胞增殖的个体发育变化中起重要作用。
