LIPOLYTIC ACTIVITY TOWARD TRI- AND MONOGLYCERIDES IN POSTHEPARIN PLASMA

Human postheparin plasma was shown to contain lipolytic activity with different properties toward similarly emulsified tri- and monoglycerides of long chain fatty acids. Monoglyceride lipolysis was found to proceed at an about 6 fold faster rate than triglyceride lipolysis, was much less susceptible to inhibition by protamine sulfate or 1 M Nacl and had a more alkaline pH optimum. Distinctive features of plasma esterolytic activity toward tri- and monobutyrin are also presented. The question whether these lipolytic activities are due to one or more enzymes is discussed and some characteristics of the lipolytic activity in plasma are compared with those of the lipolytic activity in tissue homogenates. The need for careful selection of substrate for the measurement of specific triglyceride lipolysis in postheparin plasma is indicated. © 1968.