Assay and characterization of serum-stimulated lipolytic activity in homogenates of human adipose tissue.
An assay of lipolytic activity in human adipose tissue is described, in which native homogenates of the adipose tissue yield the enzyme, as well as the triglyceride substrate, and the emulsifying phospholipids. The lipolytic activity in the presence of serum is characterized mainly as lipoprotein lipase activity by a pH-optimum of 8.0, by the fact that serum is necessary for full activity, and that it is inhibited by 1 M NaCl and by protamine. At serum concentrations of higher than 50% a marked inhibition of the lipolysis is observed. Noradrenaline, insulin, and heparin have no effect on the serum-stimulated lipolytic activity.
Assay and characterization of serum-stimulated lipolytic activity in homogenates of human adipose tissue. An assay of lipolytic activity in human adipose tissue is described, in which native homogenates of the adipose tissue yield the enzyme, as well as the triglyceride substrate, and the emulsifying phospholipids. The lipolytic activity in the presence of serum is characterized mainly as lipoprotein lipase activity by a pH-optimum of 8.0, by the fact that serum is necessary for full activity, and that it is inhibited by 1 M NaCl and by protamine. At serum concentrations of higher than 50% a marked inhibition of the lipolysis is observed. Noradrenaline, insulin, and heparin have no effect on the serum-stimulated lipolytic activity.