The effect of raised inspired carbon dioxide on normal retinal vascular development in the neonatal rat.
OBJECTIVE
Raised arterial carbon dioxide levels have been suggested as a risk factor for retinopathy of prematurity (ROP). We investigated the effect of raised inspired CO2 on normal postnatal vasculogenesis in the neonatal rat retina.


METHODS
One hundred fifty newborn rat pups were divided among 15 mothers (n = 10 for each litter). Five litters were exposed to low CO2 (0.2%), 5 litters exposed to 6%, and 5 litters to 10% CO2. On day 7 of life the rats were sacrificed and the total retinal and vascularized retinal areas analyzed.


RESULTS
The vascularized retinal area and ratio of vascularized to total retinal area were reduced in rats exposed to 6% and 10% CO2.


CONCLUSIONS
Raised inspired CO2 was associated with retardation of normal retinal vascular development and increased peripheral avascular area in neonatal rats. Raised CO2 may be a risk factor for the development of abnormal neovascularization such as in ROP.
Holmes
J M
JM
Mayo Clinic, Department of Ophthalmology, Rochester, MN 55905, USA.
Leske
D A
DA
Zhang
S
S
D000818:Animals; D000831:Animals, Newborn; D002245:Carbon Dioxide / Q000008:administration & dosage; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D006801:Humans; D006935:Hypercapnia / Q000503:physiopathology*; D007231:Infant, Newborn; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012119:Respiration; D015861:Retinal Neovascularization / Q000473:pathology / Q000503:physiopathology*; D012171:Retinal Vessels / Q000254:growth & development / Q000473:pathology* / Q000503:physiopathology; D012178:Retinopathy of Prematurity / Q000473:pathology / Q000503:physiopathology
D002245:Carbon Dioxide