Computerized digital image analysis of retinal vessel density: Application to normoxic and hyperoxic rearing of the newborn rat

Penn, John S.; Gay, Creston A.

doi:10.1016/0014-4835(92)90045-t

Cited by 16 publications

(9 citation statements)

References 11 publications

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“…Those in which the vasculature bed is perfused with colored or fluorescent dye [18][19][20][21] provide information similar to that obtained by fluorescein angiography, but do not offer the opportunity to detect or quantitate pericyte loss and capillary degeneration, important histological markers of early stage of the retinopathy. Isolation of retinal vasculature allows histological as well as immunohistological analysis carried out on capillary cells.…”

Section: Methods To Study the Retinal Vasculaturementioning

confidence: 99%

In vivo Models of Diabetic Retinopathy

Zheng

Kern²

2009

Experimental Approaches to Diabetic Retinopathy

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Diabetic animal models studied to date have developed some lesions characteristic of the early stages of diabetic retinopathy. This spectrum of lesions includes degenerate and nonperfused (acellular) capillaries, loss of capillary cells, thickening of basement membranes, and in longer-lived species, microaneurysms and intra-retinal microvascular abnormalities. To date, none of these diabetic animal models has been found to reliably develop preretinal neovascularization (an advanced stage of the retinopathy), likely due in part to less vaso-obliteration occurring during the short duration of diabetes that these models have been studied compared to diabetic patients. Although not diabetic, some animal models develop a diabetic-like preretinal neovascularization, and these models have been used to study ways to inhibit the neovascularization. Animal models are being used to provide valuable insight into the roles of specific biochemical pathways or physiological abnormalities in the development of diabetic retinopathy. Distinct advantages and disadvantages of each of these models are outlined in this review, thus providing information that should be valuable for planning experimental studies pertaining to the retinopathy.

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Section: Methods To Study the Retinal Vasculaturementioning

confidence: 99%

In vivo Models of Diabetic Retinopathy

Zheng

Kern²

2009

Experimental Approaches to Diabetic Retinopathy

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“…Procedures complied with the Polish legislation concerning experiments on animals and were approved by a local care committee. Some litters with their mothers were kept in room air (normoxia), while the others were exposed first to hyperoxia (60% or 80% oxygen) and then to normoxia (relative hypoxia) [19,20,24,25]. Hyperoxia was applied for 2 weeks.…”

Section: Methodsmentioning

confidence: 99%

“…The rat model of ROP is based on the fact that the retina of the newborn rat resembles that of human foetus from 24±26 weeks of gestational age. The retinopathy is produced by prolonged high oxygen supplementation [19,20,24,25] followed by a period of room air recovery [24,25]. Hyperoxia is associated with a reduced density of retinal blood vessels [19,20] whereas hyperoxia followed by normoxia is associated with increased neovascularisation of the retina [24,25].…”

Section: Introductionmentioning

confidence: 99%

Polyamine system in developing rat eye and an animal model of retinopathy of prematurity

Grałek

Sasiak

Wójcik

et al. 1999

Graefe's Archive for Clinical and Experimental Ophthalmology

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l Background: In experimental models of retinopathy of prematurity (ROP), a vasoproliferative disorder of the retina, retinal lesions are usually assessed by morphological examination. However, studies suggest that the polyamine system may be useful in monitoring proliferation processes. For this reason, polyamine concentrations in rat erythrocytes (RBC) and the regulation of polyamine system in rat eyes under the conditions relevant to ROP were investigated. l Methods: Newborn Wistar rats were reared in room air (control) or exposed first to hyperoxia (60% or 80% oxygen, 2 weeks) and then to normoxia (relative hypoxia, 1 or 2 weeks). Blood was collected from orbital vessels at 2 weeks of age and before death. Polyamine system-related enzyme activities were measured in retina and lens with radioassays. Polyamines were quantified by fluorometry after extraction, dansylation and HPLC separation. l Results: Oxygen (80% only) significantly decreased RBC polyamine concentrations, which then markedly increased after rats were transferred for a week to normal air, suggesting retardation of growth processes and compensatory stimulation, respectively. However, polyamine system changes in the rat eye were not so pronounced. Enzyme activities and polyamine concentrations tended to be lower in retina after hyperoxia and were only slightly higher, with the exception of ornithine decarboxylase, after a subsequent 1 week of normoxia. In litters subjected to normoxia for longer periods no changes were found. l Conclusion: The transient and short-lived alteration in polyamine metabolism, especially in the eye, suggests that exposure of newborn rats to high oxygen supplementation followed by normoxia does not necessarily result in marked retinopathy.

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“…To examine the effects of hyperoxia on TGF-␣ retinal expression, whole eyes were obtained from neonatal rats that were continuously exposed to 80% oxygen for 10 days after birth (10 O 2 ), or 10 days hyperoxia followed by 4 days in room air (10/4 O 2 ). Because the hyperoxia exposure results in vaso-obliteration of retinal vessels it allows the examination of TGF-␣ and its receptor in response to subsequent vascular non-perfusion in the developing retina of postnatal animals (9,10). The pups were sacrificed by cervical dislocation or CO 2 euthanasia.…”

Section: Animalsmentioning

confidence: 99%