Animal model of retinopathy of prematurity

Summary

Retinopathy of prematurity (ROP), formerly known as posterior lens fibroplasia, is a proliferative retinopathy. It is characterized by abnormal retinal vascularization, neovascularization, fibrous proliferation and retinal detachment in preterm infants, which can lead to a variety of serious complications, including lifelong blindness. In preterm infants, their peripheral retinal vasculature has not yet developed, and the presence of areas of undeveloped vasculature is the pathogenesis of retinopathy of prematurity.

Principle

Hyperoxic environments are characterized by retinal vascular proliferation similar to ROP.

Appliance

Continuous high concentration of oxygen caused the vasoconstriction and narrowing or even occlusion of the retinal vessels in mouse littermates, with a large area of no perfusion in the central part of the retina, and the relative hypoxia caused obvious dilatation and tortuosity of the retinal macrovessels, and the formation of a large number of structurally abnormal neovascularization. This model is a suitable model to study the mechanism of neovascularization and related treatment of retinopathy of prematurity.

Operation method

Establishment of an animal model of retinopathy of prematurity

Principle

Placing mice into a hyperoxic environment results in retinal vascular proliferation similar to ROP.

Materials and Instruments

Animal model:
0-7 day old mice.
Equipment:
Syringe, gelatin sponge, ophthalmic scissors.
Reagents:
1% chloral hydrate;
Alcohol.

Move

The animal model of retinopathy of prematurity was modeled as follows:

(I) Model preparation: A

. Clean-grade Wistar rats and their lactating females were placed in an airtight oxygen chamber, connected to 100% humid medical oxygen, and the gas flow rate was adjusted to 0.5-0.75 L/min three times a day (9 am, 2 pm, 6 pm).

B. Use the oxygen meter to monitor the oxygen concentration in the outlet tube to keep it at 75%±1%; keep the temperature at 22-25 ℃ and the humidity at 50%-70%.

C. Replace the bedding and feed in the box once every 2 days, and open the box for about 0.5 hours.

D. After 5 days of rearing in this environment, the rats were taken out of the oxygen tank and reared in a normoxic environment.

(ii) Test methods:

Method 1: Omental film

ing

Retinal smears (ADPase staining) were performed on postnatal days 12 (P12), 14, and 17, respectively.

A, The eyes were anesthetized intraperitoneally with 1% hydralazine (1 mL/kg), the eyeballs were removed by amputation, the cornea was removed with ophthalmic scissors, the root of the optic nerve was clamped with ophthalmic forceps, and the lens and vitreous body were removed by gently squeezing forward from the root of the optic nerve with a small brush, the retina was stripped, and the retina was fixed in 4% paraformaldehyde overnight.

B, The retina was rinsed with Tris-maleic acid buffer, incubated in 37 ℃ reaction solution for 15 minutes, and reacted in 10% ammonium sulfide for 1 minute.

C. Observe the morphology, distribution and number of retinal blood vessels under a light microscope. If the morphology of retinal blood vessels was abnormal, the model was qualified.

Method 2: Preparation and observation of retinal tissue sections

A. The cervical vertebrae of rat pups were dissected and killed, and the eyeballs were removed. The eyeballs were immersed in 4% paraformaldehyde fixative for 48 hours and then dehydrated routinely.

B. Paraffin-embedded, continuous sagittal slices were made parallel to the cornea to the optic disc, with a thickness of 46 μm, and 20 slices were selected from each eye (the section with the optic nerve was removed) for examination.

C, Hematoxylin eosin (HE) stained sections, and the number of nuclei of vascular endothelial cells breaking through the inner border membrane of the retina were counted under the microscope. It reflects the proliferation of retinal blood vessels.

For more product details, please visit Aladdin Scientific website.

https://www.aladdinsci.com/