The Estimation of Creatinine in Serum

Abstract

Although the clearance of endogenous creatinine as a measure of the glomerular filtration rate has been much criticized, it remains the only possible measure where repeated or continuous investigation is needed, and has already yielded much useful information. When we started to use it, however, it became apparent that while the estimation of creatinine in urine was satisfactory, that of plasma creatinine was not. The purpose of this work was therefore to establish a standard method of estimation simple enough for routine use. When this had been evolved it was used for a series of creatinine clearances, which were compared with simultaneous inulin clearances to see whether a reasonable agreement was apparent.

Handling of phosphate by the human kidney at high plasma concentrations

“…At first, clearances were determined and were found, as claimed by Brod & Sirota (1948), to be close to inulin clearance. We later confirmed the observations of Roscoe (1953), indicating that this agreement is purely fortuitous and dependent upon slow development of colour from the acid plasma filtrate. Henceforward creatinine output was compared with inulin clearance, for a rough proportionality and similar directional changes.…”

Effects of creatine supplementation on the performance and body composition of competitive swimmers

“…To determine blood lactate concentrations after exercise [27], fingertip blood samples (25 L) were collected at the end of the 50-m and 100-m tests and at the end of each 50-m series (trials 3, 6, and 9). These samples was stored at Ϫ80°C, and blood lactate concentration was enzymatically analyzed 24 hours after the test using a lactate analyzer YSI 1500 Sport L-Lactate Analyser (Yellow Spring Incorporated, OH, USA).…”

“…For urinary creatine [26] and creatinine [27] excretion, 24-hour urine collections were taken at baseline and on day 2 of supplementation.…”

“…For serum creatinine concentrations [27], blood was collected at baseline and on day 2 of supplementation. Venous blood samples was centrifuged for separation of plasma and serum, which was stored at Ϫ80°C until analysis 1 day later.…”

Hypoglycaemic Effect of Glibenclamide: A Critical Study on the Basis of Creatinine and Lipid Peroxidation Status of Streptozotocin-induced Diabetic Rat

“…Creatinine estimation was followed by Jaffe's method [33,34] . All the reagents and the samples were brought to a reaction temperature of 37°.…”