Biomaterial Database

Extensive tubular secretion and reabsorption of creatinine in humans. 1988

P A Sjöström, and B G Odlind, and M Wolgast

Department of Internal Medicine, Orebro Medical Center Hospital, Sweden.

The validity of creatinine as a marker for the glomerular filtration rate was studied in 8 healthy volunteers in different stages of hydration and during large variations in urinary flow rates. The urine flow was 8.4 ml/min in a dehydrated state (due to furosemide infusion; 8 mg/h) and raised to 23.2 ml/min after rapid rehydration. The creatinine to inulin clearance ratio changed considerably from 1.47 in rehydrated state, indicating a substantial tubular secretion of creatinine, to 1.05 in dehydrated state, indicating a reabsorption of creatinine almost equal to secretion. Thus, substantial tubular secretion and reabsorption of creatinine, changing in relative importance in relation to the degree of hydration, make creatinine clearance an unreliable marker for the glomerular filtration rate.

UI	MeSH Term	Description	Entries
D007444	Inulin	A starch found in the tubers and roots of many plants. Since it is hydrolyzable to FRUCTOSE, it is classified as a fructosan. It has been used in physiologic investigation for determination of the rate of glomerular function.
D007684	Kidney Tubules	Long convoluted tubules in the nephrons. They collect filtrate from blood passing through the KIDNEY GLOMERULUS and process this filtrate into URINE. Each renal tubule consists of a BOWMAN CAPSULE; PROXIMAL KIDNEY TUBULE; LOOP OF HENLE; DISTAL KIDNEY TUBULE; and KIDNEY COLLECTING DUCT leading to the central cavity of the kidney (KIDNEY PELVIS) that connects to the URETER.	Kidney Tubule,Tubule, Kidney,Tubules, Kidney
D008297	Male		Males
D001806	Blood Urea Nitrogen	The urea concentration of the blood stated in terms of nitrogen content. Serum (plasma) urea nitrogen is approximately 12% higher than blood urea nitrogen concentration because of the greater protein content of red blood cells. Increases in blood or serum urea nitrogen are referred to as azotemia and may have prerenal, renal, or postrenal causes. (From Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)	BUN,Nitrogen, Blood Urea,Urea Nitrogen, Blood
D003404	Creatinine		Creatinine Sulfate Salt,Krebiozen,Salt, Creatinine Sulfate,Sulfate Salt, Creatinine
D005919	Glomerular Filtration Rate	The volume of water filtered out of plasma through glomerular capillary walls into Bowman's capsules per unit of time. It is considered to be equivalent to INULIN clearance.	Filtration Rate, Glomerular,Filtration Rates, Glomerular,Glomerular Filtration Rates,Rate, Glomerular Filtration,Rates, Glomerular Filtration
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D014882	Water-Electrolyte Balance	The balance of fluid in the BODY FLUID COMPARTMENTS; total BODY WATER; BLOOD VOLUME; EXTRACELLULAR SPACE; INTRACELLULAR SPACE, maintained by processes in the body that regulate the intake and excretion of WATER and ELECTROLYTES, particularly SODIUM and POTASSIUM.	Fluid Balance,Electrolyte Balance,Balance, Electrolyte,Balance, Fluid,Balance, Water-Electrolyte,Water Electrolyte Balance