[Effects of adenosine on the electrophysiology of the retina]

To the authors' knowledge, adenosine has not yet been shown to play any functional role in the mammalian retina, although it has been shown that it induces neuromodulation and an antiepileptogenic action of the purine in the brain. In order to test effects on retinal function, adenosine was administered intraarterially, in micromolar concentrations, to dark-adapted, isolated, perfused cat eyes. Light-evoked (rod-matched) electrical signals were recorded. Adenosine induced a marked increase in the amplitude of the ERG b-wave, a dose-dependent depression of the optic nerve response, and an increase in the flow rate of the perfusate - indicative of vasodilation. These data, together with autoradiographically demonstrated uptake of adenosine (2) are the first evidence that adenosine plays a functional role at several sites in the cat retina.