GABA receptor binding site "induction" in rabbit retina after nipecotic acid treatment: changes during postnatal development.
The development of the GABA system in the rabbit retina was studied. The number of high- and low-affinity GABA receptor binding sites increased in a sigmoidal manner, with the curve for the low-affinity sites lagging 2-3 days behind that for the high-affinity sites. The KD for both high- (17.5 nM) and low-affinity (138.0 nM) sites remained constant during development. Treatment of isolated eyecups with the uptake blocker nipecotic acid resulted in an increase in the Bmax for high-affinity sites in developing tissue with the maximum sensitivity around eye opening; mature tissue exhibited a decrease in Bmax. In contrast, a gradual decrease in sensitivity to stimulation of the low-affinity sites occurred. These data indicate that the "trophic" action of GABA is limited to the time when the tissue is developing.
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D009557:Nipecotic Acids / Q000494:pharmacology*; D011392:Proline / Q000031:analogs & derivatives*; D011817:Rabbits; D011963:Receptors, GABA-A / Q000032:analysis*; D012160:Retina / Q000032:analysis* / Q000254:growth & development
D009557:Nipecotic Acids; D011963:Receptors, GABA-A; C030278:nipecotic acid; D011392:Proline; C010983:homoproline