ρ1 GABAC receptors are expressed in fibrous and cartilaginous layers of chick sclera and located on sclera fibroblasts and chondrocytes

Abstract

rho(1) GABA(C) receptor antagonists inhibit myopia in chick but the site of this effect is not known. The sclera ultimately determines the shape and size of the globe and thus an untested possibility is that GABA agents have a scleral mechanism. Whether rho(1) GABA(C) receptors are expressed and located in chick sclera is unknown. Real-time PCR, western blot and immunohistochemistry were used to determine whether rho1 GABA(C) receptors are expressed and located in chick fibrous and cartilaginous sclera. Both layers of the chick sclera were positive for rho1 GABA(C) receptor mRNA (PCR) and protein (western blot) expression and labeling was observed in both fibroblasts and chondrocytes of the fibrous and cartilaginous layers (immunohistochemistry). These investigations clearly show that chick sclera possesses rho(1) GABA(C) receptors. The sclera is thus a potential previously unrecognized site for activity of rho(1) GABA(C) agents.