Calcium uptake activity was assayed in liver microsomal vesicles from fed and fasted rats. This activity required ATP and was stimulated by the calcium trapping agent oxalate. The most striking feature was the low rate of calcium accumulation in liver microsomes from fasted rats. Maximal rate was inhibited up to 66 and 82% after 1 and 3 days starvation, respectively. This defective microsomal calcium handling suggests its possible involvement in the massive glycogen breakdown during starvation.
