Role of P2X7 receptors in the development of diabetic retinopathy

Figure 1 Cell death induced in non-diabetic and diabetic retinal microvessels by the P2X₇ agonist, benzoylbenzoyl adenosine triphosphate. From Sugiyama et al[30] with permission from Investigative Ophthalmology and Visual Sciences. BzATP: Benzoylbenzoyl adenosine triphosphate.

Figure 2 Typical changes of electroretinography after intravitreal injection (IV) of benzoylbenzoyl adenosine triphosphate (50 nmol) or physiological saline solution in an alloxan-induced diabetic rabbit. The amplitudes of a and b waves and oscillatory potentials were reduced in the BzATP-treated eye. From Sugiyama et al[32] with permission from Archives of Ophthalmology. BzATP: Benzoylbenzoyl adenosine triphosphate.

Figure 3 Models of the physiological and pathobiological effects of adenosine 5’-triphosphate in the retinal microvasculature. A: Putative mechanisms regulating purinergic vasotoxicity; B: Putative mechanisms by which extracellular adenosine 5’-triphosphate (ATP) causes pericyte Ca²⁺ levels to rise and thereby the contraction of these mural cells and the constriction of adjacent lumens. From Sugiyama et al[33].