INTRODUCTION
1.1 Creatinine and its importance
Creatinine (C4H7N3O), a nitrogenous organic compound, is found in
muscle tissue and blood. It is normally excreted in the urine as metabolic
waste. Urinary excretion of creatinine is relatively constant from day to day and
reflects mainly the amount of muscle tissue in the body. Therefore the amounts
of various components of urine are often expressed relative to creatinine. It is
mainly filtered by the kidney, though a small amount is actively secreted. There
is little-to-no tubular re-absorption of creatinine. If the filtering of the kidney is
deficient, creatinine levels rise. As a result, creatinine blood levels may be used
to calculate Creatinine Clearance (CCR), which reflects the Glomerular Filtration
Rate (GFR). The GFR is clinically important because it is a measurement of
renal function. Measurement of creatinine levels in serum and determination of
renal clearance of creatinine is widely used for laboratory diagnosis of renal
and muscular function [Madaras and Buck, (1996)]. The Schematic diagram of
creatinine is shown in Figure 1.1
