Purchase this article with an account.
Verleen McSween, Suresh Viswanathan, Joseph Bonanno, Stephen Burns, Shimin Li; Intracellular pH of Retinal Ganglion Cells During Systemic Hypoxia. Invest. Ophthalmol. Vis. Sci. 2013;54(15):6324.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Previously we showed that intracellular pH of retinal ganglion cells (RGCs) decreases as a result of acute elevation of intraocular pressure (IOP) (McSween et al. ARVO 2012). The purpose of the current study was to provide confirmatory data by examining other perturbations, such as systemic hypoxia, that should also affect RGC pH.
RGCs were retrograde labeled in anesthetized adult male Brown Norway rats by superior colliculus injection of 10kD Alexa Fluor 790 dextran and the pH sensitive dye 2'-7'-bis (carboxyethyl)-5(6)-carboxyfluorescein (BCECF) dextran (30 mg/ml, 20 µl). Retinal fluorescence was measured with a confocal scanning laser ophthalmoscope (HRA2, Heidelberg Engineering®) before, during and after breathing 10% oxygen (90% nitrogen) for 4 minutes via a nose cone at 2 weeks following dye injections. The retinal images were processed using custom MATLAB software and the fluorescence of individual cells was analyzed using the MetaMorph® image analysis software.
The fluorescence intensity of 517 double labeled cells was tracked. The intensity of Alexa790 labeling was not significantly different before, during and after 10% oxygen breathing. The intensity of BCECF labeling reduced by 19+11% during 10% oxygen breathing relative to breathing room air (p<1x10-10) and returned to 97+14% of control intensity on restoration to breathing room air (p<4x10-7).
Retinal hypoxic changes arising from systemic hypoxia can be reliably measured in vivo. The changes seen are reversible and support our previous report that acute elevation of IOP decreases RGC intracellular pH.
This PDF is available to Subscribers Only