Determination of renal clearance of neopterin by a pharmacokinetic approach.
Pharmacokinetic modelling was used to determine the glomerular filtration rate and tubular secretion of neopterin, a marker for cellular immune activation. The method involves parameter identification employing the transient venous plasma concentration profiles of marker substances. By combined i.v. injection of neopterin and inulin which is excreted exclusively via glomerular filtration, neopterin was shown to be excreted in addition to glomerular filtration, by tubular secretion: clearance of inulin, 112 (S.D. 2.2) ml/liter; clearance of neopterin, 499 (S.D. 79.7) ml/min. A pilot experiment using in addition p-amino hippuric acid suggests that neopterin and p-amino hippuric acid may employ the same carrier system for tubular secretion.
Estelberger
W
W
Institut für Medizinische Chemie, Universität Graz, Austria.
Weiss
G
G
Petek
W
W
Paletta
B
B
Wachter
H
H
Reibnegger
G
G
D000328:Adult; D001708:Biopterins / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D005919:Glomerular Filtration Rate; D006801:Humans; D007444:Inulin / Q000493:pharmacokinetics; D007668:Kidney / Q000378:metabolism*; D007684:Kidney Tubules / Q000378:metabolism; D007700:Kinetics; D008297:Male; D008433:Mathematics; D008657:Metabolic Clearance Rate; D008954:Models, Biological; D019798:Neopterin; D010130:p-Aminohippuric Acid / Q000493:pharmacokinetics
D001708:Biopterins; D019798:Neopterin; D007444:Inulin; D010130:p-Aminohippuric Acid