Effect of Chlorella-Extract Supplementation to Diet on in vitro Lipolysis in Ayu

Abstract

The effect of supplemental dietary Chlorella-extract on lipid mobilization in ayu Plecoglossus altivelis was investigated in terms of in vitro lipolysis in cell free system of intraperitoneal fat body (IPE). The lipolysis activity was measured as the amount of fatty acids liberated from IPF homo-genate in the presence or absence of lipolytic hormones (adrenaline, noradrenaline, cortisol, glucoagon, vasopressin).
The control group was fed a commercial diet containing 4% feed oil. In an experimental group, 1% of Chlorella-extract was supplemented to the above diet. The tissue homogenates obtained from both groups could liberate free fatty acids by incubation even without lipolytic hormones. However, cyclic AMP had no influence in the lipolysis activity. The lipolysis activity was superior in the experimental group. The lipolysis of the control group was enhanced by cortisol, while in addition to cortisol, noradrenaline and vasopression could activate the reaction in the experimental group.
Even after starvation for 10 days, the lipolysis activity in the experimental fish was higher than that of control group. Selective release of certain fatty acids was found in the lipolysis in both groups. The lipolysis activity which is linked to mobilization of the reserved lipids could thus be enhanced by feeding Chlorella-extract.