Vasoproliferation in the neonatal dog model of oxygen-induced retinopathy

Invest Ophthalmol Vis Sci. 1996 Jun;37(7):1322-33.

Abstract

Purpose: To examine the time course and relative degree of proliferative response associated with revascularization after hyperoxic insult in the dog model of oxygen-induced retinopathy.

Methods: Mitotic cell profiles (MCPs) were counted in serial cross-sections of ADPase flat-embedded retinas of air-reared control 8-, 15-, and 22-day-old dogs and of age-matched oxygen treated animals (4 days, 100% oxygen) after return to normoxia. Sectioning and analysis were performed along the radial axis of the forming primary vasculature from optic nerve head to periphery.

Results: In air-reared control animals, lumenal-associated cell mitosis was low, with an average of 9.6 MCPs/mm2 of nerve fiber layer tissue in the 8-day-old dogs, 6.5 MCPs/mm2 in the 15-day-old dogs, and 8.4 MCPs/mm2 in the 22-day-old dogs. In oxygen-treated animals, however, the number of lumenal-associated MCPs was significantly higher, with an average of 52.5 MCPs/mm2 of tissue in the 8-day-old dogs, 45.1 MCPs/mm2 in the 15-day-old dogs, and 26.8 MCPs/mm2 in the 22-day-old dogs. Additionally, extracellular spaces in avascular retina were obliterated in oxygen-treated animals.

Conclusions: This study demonstrates that in the neonatal dog, revascularization after hyperoxic insult involves a period of marked vasoproliferation that peaks somewhere between 3 to 10 days after return to room air. Oxygen-induced changes in the extravascular milieu are likely to affect the pattern of reforming vasculature and may restrict growth anteriorly.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aging / pathology
  • Animals
  • Animals, Newborn
  • Astrocytes / pathology
  • Disease Models, Animal
  • Dogs
  • Humans
  • Hypoxia / complications
  • Infant, Newborn
  • Mitosis
  • Mitotic Index
  • Nerve Fibers / pathology
  • Optic Nerve / pathology
  • Oxygen / adverse effects*
  • Retinal Neovascularization / pathology*
  • Retinal Vessels / pathology*
  • Retinopathy of Prematurity / etiology
  • Retinopathy of Prematurity / pathology*
  • Time Factors

Substances

  • Oxygen