Intraocular injections of nipecotic acid produce a preferential block of neuronal 3H-GABA accumulation in adult rabbit retina.
A procedure by which the activity of the retinal GABA uptake system can be manipulated in vivo has been developed. Intraocular injections of nipecotic acid, a proported GABA uptake blocker, were administered to adult rabbits every 48 hours for a two-week period. No behavioral or systemic changes were observed. Injections were well-tolerated with less than 10% loss of the tissue caused by physical damage or injection. Biochemical analyses demonstrated a dose-dependent inhibition of 14C-GABA uptake into retinal tissue. No effect on uptake was observed for saline-treated tissue. Autoradiographic analyses showed that in vivo treatment with nipecotic acid preferentially blocked accumulation of 3H-GABA into the amacrine cell bodies and processes in the inner plexiform layer. This treatment may be especially useful in assessing the functional significance of GABA transport in vivo.
D000818:Animals; D001345:Autoradiography; D004305:Dose-Response Relationship, Drug; D018756:GABA Antagonists; D007267:Injections / Q000379:methods; D009474:Neurons / Q000378:metabolism; D009557:Nipecotic Acids / Q000008:administration & dosage / Q000494:pharmacology*; D011817:Rabbits; D012160:Retina / Q000378:metabolism*; D014316:Tritium; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D018756:GABA Antagonists; D009557:Nipecotic Acids; D014316:Tritium; D005680:gamma-Aminobutyric Acid