Sangild P T, Sjöström H, Norén O, Fowden A L, Silver M
Department of Clinical Studies, Reproduction, Royal Veterinary and Agricultural University, Copenhagen, Denmark.
Pediatr Res. 1995 Feb;37(2):207-12. doi: 10.1203/00006450-199502000-00014.
The development of brush-border enzymes and the possible regulatory role of cortisol were investigated in the small intestine of the fetal and neonatal pig. With the sows under pentobarbitone anesthesia, osmotic minipumps containing either saline or cortisol were inserted s.c. into 25 fetuses from 10 pregnant sows (82-96 d gestation). Six d later, the infused fetuses were removed by cesarean section and samples of the proximal, middle, and distal intestine taken for analysis. Samples were also obtained from 48 piglets that did not undergo an operation (controls) and that were removed at intervals from 82 d gestation until term (114 +/- 2 d). In the proximal and middle intestine, the mean levels of lactase-phlorizin hydrolase (EC 3.2.1.23-62), maltaseglucoamylase (EC 3.2.1.20), aminopeptidase N (EC 3.4.11.2), and aminopeptidase A (EC 3.4.11.7) increased during the last 10-15 d before term, correlated positively with log10 plasma cortisol values, and were higher in cortisol-infused than in saline-infused fetuses (p < 0.05). Activity of sucrase-isomaltase (EC 3.2.1.48-10) was low in fetal pigs, and this enzyme and dipeptidyl peptidase IV (EC 3.4.14.5) were not significantly affected by fetal age or exogenous cortisol. Maltase (EC 3.2.1.48-10 and EC 3.2.1.20) activity was significantly decreased in the middle and distal intestine of cortisol-infused fetuses. The results suggest that the prepartum rise in endogenous cortisol secretion stimulates the prenatal expression of certain brush-border enzymes in the pig small intestine at this critical time. However, the effects of cortisol on the developing intestine were highly idiosyncratic for particular enzymes and intestinal regions.
研究了胎儿和新生仔猪小肠中刷状缘酶的发育情况以及皮质醇可能的调节作用。在戊巴比妥麻醉下，将含有生理盐水或皮质醇的渗透微型泵皮下植入10头怀孕母猪的25只胎儿体内（妊娠82 - 96天）。6天后，通过剖宫产取出注入药物的胎儿，并采集近端、中段和远端小肠样本进行分析。还从48只未接受手术的仔猪（对照组）获取样本，这些仔猪从妊娠82天开始每隔一段时间取出，直至足月（114±2天）。在近端和中段小肠中，乳糖酶 - 根皮苷水解酶（EC 3.2.1.23 - 62）、麦芽糖酶 - 葡糖淀粉酶（EC 3.2.1.20）、氨肽酶N（EC 3.4.11.2）和氨肽酶A（EC 3.4.11.7）的平均水平在足月前的最后10 - 15天升高，与log10血浆皮质醇值呈正相关，且注入皮质醇的胎儿中的这些酶水平高于注入生理盐水的胎儿（p < 0.05）。蔗糖酶 - 异麦芽糖酶（EC 3.2.1.48 - 10）在胎儿猪中的活性较低，该酶和二肽基肽酶IV（EC 3.4.14.5）不受胎龄或外源性皮质醇的显著影响。注入皮质醇的胎儿中段和远端小肠中的麦芽糖酶（EC 3.2.1.48 - 10和EC 3.2.1.20）活性显著降低。结果表明，产前内源性皮质醇分泌的增加在这个关键时期刺激了猪小肠中某些刷状缘酶的产前表达。然而，皮质醇对发育中小肠的影响因特定酶和肠段而异。
