Pseudocholinesterase blood plasma activity and albumin concentration in cats with hepatopathies

Abstract

Pseudocholinesterase (serum cholinesterase, ChE) is a common marker of liver protein synthesis capacity in humans. Little is known about its role in hepatopathies in companion animals. The aim of the present study was to investigate the relevance of blood plasma ChE activity in cats suffering from hepatopathy. ChE activity and for comparison plasma albumin concentrations were measured in heparinised blood plasma samples of 132 cats with histologically confirmed hepatopathy (classified into seven different groups), in 12 cats with no histological liver abnormality and in a control group of 65 healthy cats. ChE activity was measured with a colorimetric assay that is based on the substrate butyrylthiocholine. All groups, including the group of sick cats with no histologically detectable liver abnormalities had decreased plasma ChE activities compared to the control group (P < 0.05). However, due to the wide reference range (462–7,147 U/L), only six of the 132 cats with histologically detectable liver diseases had ChE activities below the reference range. The overall sensitivity of ChE activity was significantly lower when compared to the plasma albumin concentration. The results indicate that single plasma ChE activity measurements have only limited value in assessing liver function in cats.