Electroconvulsive shock and norepinephrine uptake kinetics in the rat brain.

The kinetic constants, apparent Km and Vmax, for the uptake of 3H-1-norepinephrine in cerebral cortical homogenates of the rat brain were not altered 5 min after a single electroconvulsive shock (ECS). However, one day after the last of a series of 14 ECS the apparent Km and Vmax were significantly increased above sham-shock controls, and ECS rats lost weight. Three days after the last ECS apparent Km and Vmax were significantly decreased, while the rate of weight gain tripled in the ECS rats. One week after the last ECS the kinetic constants and rate of weight gain were no different from sham-shock controls. These data are indicative of the strong compensatory mechanisms in the normal rat to the alterations induced by ECS.