Esterolytic activity of blood serum in infants with hypertrophic pyloric stenosis.

Esterolytic activity of blood serum was determined in infants with hypertrophic pyloric stenosis and in healthy control children. The substrates hydrolyzed mainly by arylesterase (EC. 3.1.1.2), i.e. p-nitrophenyl esters of acetic, propionic and butyric acid were used. It was found that in infants with hypertrophic pyloric stenosis the rate of p-nitrophenyl propionate hydrolysis was significantly higher than that of the acetate or butyrate. In control group children all three substrates were hydrolysed at similar rates, and these were significantly lower than in infants with hypertrophic pyloric stenosis.