Plasma arginine esterase activity in cystic fibrosis.

Plasma arginine esterase activity was measured in 13 young adult patients with 
cystic fibrosis and in 36 control subjects. The enzyme was activated 
by treating the plasma with chloroform and ellagic acid in the 
manner described by Rao and associates (1). No difference was found 
either between the arginine esterase activities of the patients with cystic 
fibrosis and the control subjects, or between the degrees of activity 
inhibited by soybean trypsin inhibitor. Thus, the findings of Rao and 
associates of a deficiency of arginine esterase activity in the plasma 
of patients with cystic fibrosis were not confirmed. 