Postnatal renal adaptation in preterm and term lambs.
Postnatal renal adaptation in preterm and term lambs.
复制标题
早产儿和足月羔羊的产后肾脏适应。
DOI：
10.1071/rd9950491
复制
发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Ervin,MG
中科院分区：
文献类型：
--
作者：
Berry,LM;Ikegami,M;Woods,E;Ervin,MG
The present experiments determined if increases in renal reabsorptive capacity during the transition from fetal to neonatal life are gestation dependent. Renal function was studied in chronically-catheterized fetal lambs (133 +/- 1 days; term, 145-150 days). Additionally, renal function was studied in anaesthetized, ventilated, caesarean-delivered preterm lambs (109-139 days gestation) and term lambs (148 days gestation), and in 2-day-old spontaneously-delivered term lambs. Newborns < or = 120 days old received surfactant to facilitate ventilation and maintenance of physiologic blood gases. Two hours after caesarian delivery, urine osmolality, urine flow, glomerular filtration rate (GFR), and fractional sodium excretion (FENa) values were similar for all gestations. Relative to fetal values, caesarean-delivered newborn renal values included lower urine flow rates (0.20 +/- 0.03 v. 0.05 +/- 0.01 mL min-1 kg-1), higher urine osmolalities (118 +/- 15 v. 422 +/- 16 mOsmol kg-1 H2O), and no differences in GFR or FENa. Relative to caesarean-delivered newborns, 2-day newborn renal function included higher values for GFR (0.7 +/- 0.1 v. 3.0 +/- 0.1 mL min-1 kg-1) and urine osmolality (724 +/- 32 mosmol kg-1 H2O), and lower FENa (7.0 +/- 1.5 v. 0.2 +/- 0.02%), and urine flow (0.005 +/- 0.003 mL min-1 kg-1). The 132- and 139-day animals were ventilated for 5 h and 10 h respectively; the only functional change at 10 h was a decrease in FENa (7.0 +/- 1.5 v. 2.8 +/- 0.1%). It is concluded that: (1) relative to fetal animals, renal adaptive responses in anaesthetized, ventilated newborns begin within 2 h following caesarian delivery; (2) initial adaptive responses are not gestation dependent after 109 days; and (3) the combined effects of ventilation and/or anaesthesia delay postnatal renal adaptations for at least 10 h after birth.
