title: Neonatal hyperoxia: effects on nephrogenesis and long-term glomerular structure.
abstract: Preterm neonates are born while nephrogenesis is ongoing and are commonly exposed to factors in the extrauterine environment that may impair renal development. Supplemental oxygen therapy exposes the preterm infant to a hyperoxic environment that may induce oxidative stress. Our aim was to determine the immediate and long-term effects of exposure to hyperoxia, during the period of postnatal nephrogenesis, on renal development. Newborn mice (C57BL/6J) were kept in a normoxic (room air, 21% oxygen) or a controlled hyperoxic (65% oxygen) environment from birth to postnatal day 7 (P7d). From P7d, animals were maintained in room air until early adulthood at postnatal day 56 (P56d) or middle age (10 mo; P10mo). Pups were assessed for glomerular maturity and renal corpuscle cross-sectional area at P7d (control n = 14; hyperoxic n = 14). Nephron number and renal corpuscle size were determined stereologically at P56d (control n = 14; hyperoxic n = 14) and P10mo (control n = 10; hyperoxic n = 10). At P7d, there was no effect of hyperoxia on glomerular size or maturity. In early adulthood (P56d), body weights, relative kidney weights and volumes, and nephron number were not different between groups, but the renal corpuscles were significantly enlarged. This was no longer evident at P10mo, with relative kidney weights and volumes, nephron number, and renal corpuscle size not different between groups. Furthermore, hyperoxia exposure did not significantly accelerate glomerulosclerosis in middle age. Hence, our findings show no overt long-term deleterious effects of early life hyperoxia on glomerular structure.
authors: Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia.
authors: Megan R
authors: MR
authors: Sutherland
authors: Megan
authors: M
authors: O'Reilly
authors: Kelly
authors: K
authors: Kenna
authors: Kimberley
authors: K
authors: Ong
authors: Richard
authors: R
authors: Harding
authors: Foula
authors: F
authors: Sozo
authors: M Jane
authors: MJ
authors: Black
mesh_terms: D000818:Animals; D001835:Body Weight; D049109:Cell Proliferation; D005260:Female; D018496:Hyperoxia / Q000473:pathology*; D007668:Kidney / Q000254:growth & development* / Q000473:pathology; D007674:Kidney Diseases / Q000473:pathology*; D007678:Kidney Glomerulus / Q000254:growth & development* / Q000473:pathology; D008297:Male; D051379:Mice
keywords: nephrogenesis; preterm birth; renal disease; supplemental oxygen therapy