title: Instantaneous measurement of glomerular filtration rate in the isolated perfused rat kidney.
abstract: In perfusion studies on the isolated cellfree perfused rat kidney, the glomerular filtration rate (GFR) can be controlled if the GFR can be measured instantaneously. This paper reports on a GFR meter which opens this possibility. Vitamin B12 is used as a marker for the GFR. A bubble flow meter determines urine flow rates ranging from 10 up to 200 microliter-min-1. A fiberoptic colorimeter measures vitamin B12 concentrations in the urine up to 400 mg-l-1. The flow meter and the colorimeter are described in detail. The reliability of vitamin B12 as a marker for the GFR is demonstrated and, moreover, the identity of GFR values obtained with the GFR meter and those from B12 spectrophotometry is demonstrated.
mesh_terms: D000818:Animals; D005919:Glomerular Filtration Rate; D066298:In Vitro Techniques; D008722:Methods; D051381:Rats; D012212:Rheology; D013997:Time Factors; D014805:Vitamin B 12
chemical_list: D014805:Vitamin B 12