To Estimate the Activity of Lipase in Serum
29
29.1 Theory
Lipase is the enzymes that cause hydrolysis of glycerol esters of long chain fatty
acids into glycerol and free fatty acids. Only the ester bond at carbons 1 and 3 (α-
positions) is attacked, and the reaction produces two moles of fatty acid and one
mole of 2-acylglycerol (β-monoglyceride) per mole of substrate. The latter is
resistant to hydrolysis, but it can spontaneously isomerizes to the 3-acylglycerol,
that is,α-form. This isomerization splits off the third fatty acid, a process that occurs
at a much slower rate. Lipase acts at an oil-water interface on emulsified substrates.
Most of the serum lipase is produced in pancreas, but pulmonary, gastric, and
intestinal mucosa also secretes lipase. Lipase activity can also be demonstrated in
leucocytes in adipose tissue cells and in milk.
29.2 Specimen Requirements
Serum sample is used which is stable for several days at room temperature. Store
refrigerated to avoid bacterial contamination.
29.3 Principle........................................
Fatty acids released by the action of lipase on substrate for a period of 24 h at 37C
(pH 7.4) are determined by titrating against standard solutions of NaOH using
phenolphthalein as indicator.
#Springer Nature Singapore Pte Ltd. 2018
V. Kumar, K. D. Gill,Basic Concepts in Clinical Biochemistry: A Practical Guide,
https://doi.org/10.1007/978-981-10-8186-6_29
117