Abstract
Purpose:
The purpose of this study was to investigate the role of retinal glial cells on the regulation of retinal blood flow in response to modulations in systemic oxygen tension in cats.
Methods:
We measured the vessel diameter (D), blood velocity (V) and blood flow (F) simultaneously in first-order retinal arterioles using a Laser Doppler Velocimetry (LDV) system (CLBF model 100, Canon, TOKYO). The subjects were under general anesthesia during hyperoxia (100% O2, hyperoxia group) or hypoxia (10% O2, hypoxia group) for 10 minutes after intravitreal injection of L-2-aminoadipic acid (LAA), known as a gliotoxic compound, or diluted HCl used as the control.
Results:
In the hyperoxia group, the decreases in D, V, and F in response to hyperoxia were significantly attenuated in the LAA group compared with the control group (LAA: D-8.5±1.5%, V-13.8±1.5%, F-27.8±3.0% vs control: D-16.8±1.3%, V-26.3±2.0％, F-48.9±2.4%) (P<0.01). In the hypoxia group, the increases in D, V, and F were significantly reduced in the LAA group compared with control group (LAA: D+6.8±0.55%, V+33.0±0.73%, F+48.9±2.8% and control: D+14.9±1.8%, V+42.5±2.7%, F+88.9±4.7%) (P<0.05).
Conclusions:
The current findings suggest that retinal glial cells play important roles in the regulation of retinal blood flow in response to modulations in systemic oxygen tension in cats.