Una Health Ltd
Document Control
Author: E. C. Hamer
UH-POC-TM-2 Revision 1
Date of Issue 26.04.10
Photocopied versions & handwritten amendments of this document are not controlled
Page 12 of 54
Printed 27 April 2010
GPT (ALT)
Glutamic-pyruvic transaminase (GPT) - also known as alanine aminotransferase or
ALT - is a cytoplasmic hepatocellular enzyme, whose increase in blood is highly
indicative for liver damage, e.g. by hepatitis, cirrhosis or hepatic tumours.
Serum values more than 15-fold above the upper reference limit always indicate an
acute hepatocellular damage of either viral, toxic or circulatory origin. In most types
of liver disease GPT activity is higher than that of GOT, an exception is in alcoholic
hepatitis. The ratio of GPT and GOT may provide further information about the
severity of the disease and may serve as a prognostic indicator
Potassium
The human body normally contains approximately 50 mmol potassium per kg body
weight. 98 % of it is found in cells and only 2 % is found in extra-cellular fluids. This
concentration gradient plays a major role in maintaining the membrane potential of
the cells. This electric potential is responsible for the excitability of muscles and
nerves - including the heart. Potassium is also influenced by acid-base disturbances
(e.g. treatment of very high blood glucose concentrations with insulin, which can
cause hypokalaemia). Potassium is mainly excreted by the kidneys (90 %) and to a
minor degree in the faeces (10 %).
Disorders of the water and electrolyte balance occur mainly as a consequence of
other diseases. They may characteristically alter the underlying disease or may
occur as a complication of the clinical picture.
Creatinine
Creatinine is the most important marker for renal function, because it is steadily
produced in the muscles and excreted via the kidneys in the urine. Renal
insufficiency will cause a rise in serum creatinine levels because it is not excreted in
the normal quantities and accumulates in the blood.
Urea
Urea is the most important breakdown product of protein metabolism and is
produced in the liver. Adults accumulate approximately 16 g of urea daily. This
amount is mainly eliminated via the kidneys through glomerular filtration. About 40 -
50 % of urea is partially reabsorbed in the tubules. The rest is excreted via the
intestines and perspiration.
Elevated urea levels are a clearly indication of renal insufficiency, but creatinine and
urea do not reflect renal insufficiency to the same degree. Therefore both
parameters should be tested at the same time to determine the degree of renal
insufficiency.
