Neal M J, Cunningham J R, Shah M A, Yazulla S
Department of Pharmacology, UMDS, St. Thomas's Hospital, London, U.K.
Neurosci Lett. 1989 Mar 13;98(1):29-32. doi: 10.1016/0304-3940(89)90368-6.
Vigabatrin (gamma-vinyl-GABA, GVG) is an irreversible inhibitor of GABA-aminotransferase (GABA-T) that is under clinical trial as an antiepileptic drug. Rats were injected (i.p.) with GVG and killed 18 h later. GVG administration reduced retinal GABA-T activity to undetectable levels and increased the GABA content 5-fold. Immunocytochemistry using a GABA antiserum clearly revealed the presence of GABA-IR in the glial Muller cells of retinas from GVG-treated rats but not from controls. This experiment indicates that the administration of drugs which inhibit GABA-T may cause the accumulation of GABA in retinal cells that do not normally possess enough endogenous GABA to be detected by immunocytochemistry.
