Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
Nutrition. 2012 Jun;28(6):707-12. doi: 10.1016/j.nut.2011.10.003. Epub 2011 Dec 30.
Gastric development depends directly on the proliferation and differentiation of epithelial cells, and these processes are controlled by multiple elements, such as diet, hormones, and growth factors. Protein restriction affects gastrointestinal functions, but its effects on gastric growth are not fully understood.
The present study evaluated cell proliferation in the gastric epithelia of rats subjected to protein restriction since gestation. Because ghrelin is increasingly expressed from the fetal to the weaning stages and might be part of growth regulation, its distribution in the stomach of rats was investigated at 14, 30, and 50 d old.
Although the protein restriction at 8% increased the intake of food and body weight, the body mass was lower (P < 0.05). The stomach and intestine were also smaller but increased proportionately throughout treatment. Cell proliferation was estimated through DNA synthesis and metaphase indices, and lower rates (P < 0.05) were detected at the different ages. The inhibition was concomitant with a larger number of ghrelin-immunolabeled cells at 30 and 50 d postnatally.
Protein restriction impairs cell proliferation in the gastric epithelium, and a ghrelin upsurge under this condition is parallel to lower gastric and body growth rates.
胃的发育直接取决于上皮细胞的增殖和分化，而这些过程受多种因素的控制，如饮食、激素和生长因子。蛋白质限制会影响胃肠道功能，但它对胃生长的影响尚不完全清楚。
本研究评估了从妊娠开始就处于蛋白质限制状态的大鼠胃上皮细胞的增殖情况。由于 ghrelin 从胎儿期到断奶期表达逐渐增加，并且可能是生长调节的一部分，因此研究了其在 14、30 和 50 天大的大鼠胃中的分布。
尽管 8%的蛋白质限制增加了食物和体重的摄入量，但体重较低（P<0.05）。胃和肠也较小，但在整个治疗过程中比例增加。通过 DNA 合成和中期指数来估计细胞增殖，在不同的年龄检测到较低的增殖率（P<0.05）。这种抑制与出生后 30 天和 50 天 ghrelin 免疫标记细胞数量的增加是平行的。
蛋白质限制会损害胃上皮细胞的增殖，而在这种情况下 ghrelin 的增加与胃和身体生长速度的降低是平行的。
