It was recently noted that newborn mice have much higher lipase activity in plasma than rats
or humans, and that most of the activity is due to an enzyme related to the hepatic (heparin-
releasable) lipase. Here we report that this lipase is present in plasma of adult mice also. In
contrast to the high activity of hepatic lipase, the activity of lipoprotein lipase in plasma was
low and similar to that in rats. The source of the plasma lipase was probably the liver, since
we could not demonstrate hepatic lipase-like activity in any other organ. When human …