Maturation of Rb+ and PAH accumulation by rabbit anterior uvea and choroid plexus.
In vitro accumulation of radioactive para-aminohippuric acid (3H-PAH) and rubidium (86Rb+) by the anterior uvea, ciliary processes, and the choroid plexus was evaluated in tissues from newborn and various aged rabbits. Accumulation of PAH was present in the anterior uvea at 1 day of age (tissue to media ratio, T/M, of 2.1 +/- 0.2) and remained at this level for the first 14 days of life. Accumulation did not rise to adult levels until 21 days of age (T/M 5.5 +/- 0.6). Rubidium accumulation in the anterior uvea, a measure of Na+, K+-pump activity, was higher than adult values 6 hr after birth (T/M25.2 +/- 0.9). Activity remained elevated through day 28 and did not fall to adult levels until day 60 (T/M 13.4 +/- 0.6). Accumulation studies on isolated ciliary processes were similar to those obtained from anterior uveal tissue. Daily subcutaneous injections of penicillin (300,000 units/kg/day) for 1 week had no effect on anterior uvea PAH accumulation (penicillin T/M was 1.7 +/- 0.1 and saline control T/M was 2.0 +/- 0.2). Accumulation of either 3H-PAH or 86Rb+ by the choroid plexus was present 1 day after birth in amounts that were similar to adult values and did not change during the 90 days of testing.
D000618:Aminohippuric Acids / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism; D001692:Biological Transport / Q000187:drug effects; D002831:Choroid Plexus / Q000254:growth & development / Q000378:metabolism*; D002924:Ciliary Body / Q000254:growth & development / Q000378:metabolism*; D066298:In Vitro Techniques; D007498:Iris / Q000254:growth & development / Q000378:metabolism*; D009929:Organ Size; D010406:Penicillins / Q000494:pharmacology; D011817:Rabbits; D011868:Radioisotopes; D012413:Rubidium; D012964:Sodium / Q000378:metabolism*; D010130:p-Aminohippuric Acid / Q000378:metabolism*
D000618:Aminohippuric Acids; D010406:Penicillins; D011868:Radioisotopes; D012964:Sodium; D012413:Rubidium; D010130:p-Aminohippuric Acid