Abstract
Ribonuclease was assayed by measuring the U V absorption of nucleotides liberated from yeast RNA after precipitation of undigested RNA with [image] HC1 in 80% alcohol. In mice killed after 24- and 30-hr. fasting or 1 hr. after intravenous pilocarpine the enzyme activity of pancreas homogenates was significantly decreased. Results agree with available cytochemical data on presence of the enzyme in zymogen granules.