[Dose- and age-dependence of the renal tubular transport of p-aminohippuric acid (PAH) in rats after injection of single doses].
The renal excretory capacity for tubularly eliminated foreign substances can be determined with certainty by measuring the excretion of p-aminohippuric acid (PAH). To make superfluous the laborious estimation of the maximum tubular transport capacity in the framework of screening programs, the authors established those doses of PAH the single application of which permits to assess the renal tubular transport capacity of rats of differing ages. Because of its selective renal excretion, it is possible to calculate for PAH a half-time value in urine (t1/2, urine) such as commonly indicated for the serum. Except for extremely high dosages (500 mg PAH/100 g body mass: intraperitoneally), the t1/2, urine value for PAH in adult rats is independent of the dose applied. The t1/2, urine value increases in rats 5 and 10 d of age with increasing PAH doses. In rats of all age-groups, the glomerularly filtered PAH proportion increases with increasing dosage (kinetics in decreasing blood level). In rats 5 and 10 d of age, the proportion of glomerularly filtered PAH in the total amount of excreted PAH is greater than in older rats.
D000375:Aging; D000618:Aminohippuric Acids / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport; D004305:Dose-Response Relationship, Drug; D007274:Injections, Intraperitoneal; D007444:Inulin / Q000378:metabolism; D007684:Kidney Tubules / Q000378:metabolism*; D051381:Rats; D010130:p-Aminohippuric Acid / Q000008:administration & dosage / Q000378:metabolism*
D000618:Aminohippuric Acids; D007444:Inulin; D010130:p-Aminohippuric Acid
Dosisabhängigkeit und Altersgang des renalen tubulären Transportes von p-Aminohippursäure (PAH) bei Ratten nach Injektion von Einzeldosen.