抄録
(I)In vitro release of lipase from adipose.
When rat epididymal fat pads were incubated in buffer under physiological conditions, at 37°, release of lipase from the tissue was only slight in the absence of heparin, but significant on addition of heparin. Release of glucose-6-phosphate dehydrogenase under these conditions was not stimulated by addition of heparin. When epididymal fat pads were incubated in buffer under unphysiological conditions, a considerable amount of lipase was released, and addition of heparin had no significant effect on the release.
These results suggest that heparin specifically stimulates release of lipase in vitro, and that intact tissue is required for this stimulation.
Serum is required both for the optimal activity of lipase released from adipose tissue by heparin in vitro and for that of purified clearing factor lipase which appears in blood stream following intravenous heparin injection.
The former enzyme was completely precipitated by the antibody to the latter.
These results strongly suggest that the clearing factor lipase is released in blood from the adipose tissue on intravenous heparin injection. Moreover, the epididymal fat pads in vitro seem to be a suitable system to be used in the studies on the mechanism of release of clearing factor lipase by heparin.
(II)Relationship between clearing factor lipase and lipases in various tissues was examined immunochemically. Lipases extracted from the heart, lung and kidney were markedly precipitated, but pancreatic lipase was not, by the antibody to clearing factor lipase. Lipase in liver extract was slightly precipitated by the antibody to clearing factor lipase.
These results suggest that the clearing factor lipase is released in blood from such tissues as heart, lung, kidney and liver on intravenous heparin injection.
