Biology Reference
In-Depth Information
Chapter 22
Comparison of a Semiautomated Electrophoretic
System and a Quantitative Biochemical Method
for the Evaluation of Alkaline Phosphatase
Isoforms in Canine Serum
D. Proverbio, R. Perego, E. Spada, and E. Ferro
Abstract In the dog, total alkaline phosphatase (TALP) activity represents the sum
activity of isoforms produced by the posttranslational modification of two
isoenzymes. In canine serum, TALP activity is primarily due to bone (BALP),
hepatic (LALP), and corticosteroid-induced (CALP) isoforms. Different techniques
are commercially available to measure ALP isoforms. The purpose of this study
was to compare agreement of a semiautomated electrophoretic system (Hydragel 15
Iso-Pal) with a quantitative biochemical reference method that uses wheat-germ
lectin precipitation and heat inactivation techniques. Concentrations of TALP, as
well as BALP, LALP, and CALP isoforms, in 40 canine samples - including
healthy dogs and dogs with hyperadrenocorticism - were determined using both
methods. The Hydragel kit demonstrated low within-run and between-run precision
when compared to the reference biochemical method and was unable to determine,
with precision, CALP and BALP concentrations in dogs with hyperadrenocorticism.
Keywords Alkaline phosphatase • Dog • Electrophoresis • Isoforms
22.1
Introduction
Alkaline phosphatase (ALP) is an enzyme comprised of two isoenzymes in domes-
tic mammals: intestinal and tissue-nonspecific isoenzymes. Posttranslational modi-
fication of the isoenzymes results in the creation of several isoforms, including bone
(BALP), hepatic (LALP), and corticosteroid-induced (CALP) isoforms. Serum
total ALP (TALP) activity is the sum activity of all circulating isoforms. In the
dog, TALP activity is primarily due to BALP, LALP, and CALP isoforms
D. Proverbio (
*
) • R. Perego • E. Spada • E. Ferro
Dipartimento di Scienze Cliniche Veterinarie, Sezione di Clinica Medica e Diagnostica di
Laboratorio, Universit` degli Studi di Milano, Milan, Italy
e-mail:
daniela.proverbio@unimi.it
