Regulation of Activated Lipolysis by Albumin,Glucose,and H + . ∗

Summary

Isolated fat cells were incubated in two Krebs-Ringer media containing normal and low phosphate buffer concentrations with 1 g/100 ml albumin. When lipolysis was activated with 10^-5 M NE, a marked acidosis (final pH = 6.6) occurred in the medium of low buffer capacity and the lipolytic activity was significantly inhibited as compared to lipolysis in the medium with normal buffer capacity. This inhibition was partially reversed when theophylline 10^-2 M was added. When fat cells were incubated in these two media, but with glucose present or an albumin concentration of 5 g/100 ml, lipolysis proceeded at a similar rate independently of the buffer capacity of the medium.