Continuous monitoring of free fatty acid release from adipocytes by pH-stat titration

A methods for direct and continuous monitoring of free fatty acid release in adipocyte suspensions is described. Using a pH-stat apparatus the protons from the released free fatty acids are continuously titrated and the accumulated amount of OH- added is monitored on a recorder against time, the slope thus indicating the rate of free fatty acid release. Sinc pH is kept constant, an incubation medium with a low buffering capacity can be used, which gives the method a high sensitivity. Under the conditions described, free fatty acid release from 5% of maximal norepinephrine stumulation of rat adipocytes can be accurately measured and the kinetics can be followed over extended periods of time.