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Objectives

Pseudocholinesterase (PChE) is an enzyme (EC 3.1.1.8) and like albumin is synthesised in the liver. Although the two proteins are synthesised in the liver they are not interdependent and both have been used independently as an index of liver function. Because of the contrary literature data, the aim of the present study was to measure PChE activity and albumin concentration in healthy infants and compare them with adult values [1,2]. We also compared PChE and albumin values between healthy infants and infants with biliary atresia and cirrhosis. PChE activity and albumin concentration were measured in 25 infants with biliary atresia and accompanying liver cirrhosis before Kasai operation, in 10 healthy infants, as well as in 10 healthy adults undergoing elective surgery.

Methods

PChE activity was determined by the spectrophotometric method of Ellman, using butyrylthiocholine as substrate. Plasma albumin concentration was measured by electrophoresis.

Results

In infants with liver cirrhosis, PChE values were about 50% lower then in healthy infants of the same age i.e. 2–6 months (P<0.001). In healthy infants PChE activity was lower by 20% than in adults (P<0.001). Significantly lower albumin concentration in all infants than in adults has also been established (P<0.05).

Conclusion

Our results showed diminished synthesis of PChE and albumin in liver cells of infants (2-6 months). These observations would suggest that infants might be expected to differ significantly from adults in the extent to which drugs might be protein bound and in the rates of hydrolysis of ester-type drugs. It is well known that PChE is involved in the hydrolysis of muscle relaxants succinylcholine and mivacurium. According to our results, 50% lower PChE activity in infants with biliary cirrhosis may cause prolonged duration of mentioned drugs.