Format

Send to

Choose Destination
Am J Physiol. 1994 Dec;267(6 Pt 2):H2498-507.

Intraretinal oxygen distribution in rats as a function of systemic blood pressure.

Author information

1
Lions Eye Institute, University of Western Australia, Nedlands.

Abstract

Differential responses to induced changes in systemic blood pressure (BP) at different layers of both the retinal and choroidal vasculature were observed, by monitoring localized PO2 as a function of depth, in the retina and choroid of the rat eye using oxygen-sensitive recessed microelectrodes. Visual and electrophysiological localization of the microelectrode tip allowed the oxygen distribution to be related to the positions of the vascular beds of the retina and choroid. Highly reproducible intraretinal PO2 profiles were achieved. The relationship between PO2 and systemic BP was linear in the deep capillary layer of the retina (PO2 = 0.17 x BP - 2.63) and in the choriocapillaris (PO2 = 0.21 x BP + 2.95), whereas it was nonlinear in the superficial retinal capillary layer [PO2 = 40.01/[1 + (BP/66.22)-1.22]] and deep choroid [PO2 = 83.82/[1 + (BP/124.61)-0.87]]. The minimum PO2 occurred between the two retinal capillary beds, and a PO2 gradient was evident in the choroid. The contrasting responses of different layers of the two circulations reflect different blood flow control mechanisms not evident when studying the circulations as a whole.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Atypon
Loading ...
Support Center