No Change in Rat Cerebral Cortex Calmodulin Content Following Chronic Treatment with Lithium, Reserpine, Imipramine, and Lithium Combined with Reserpine or Imipramine

Abstract

Rats were treated 2-3 wk with Li, reserpine, imipramine [a polycyclic antidepressant] and combinations of Li with reserpine or imipramine. Li was given in the diet, while the other drugs were dissolved in 0.9% saline and given i.p. twice daily. The control and Li groups received only vehicle injections. Twenty-four hours after the last injection the rats were decapitated and the cerebral cortex dissected. The tissue was sliced and the noradrenaline [norepinephrine]-stimulated cAMP accumulation determined or the tissue was homogenized and centrifuged at 10,000 .times. g for 30 min and the calmodulin content determined in the pellet and the supernatant. Reserpine treatment caused 50% increase in the noradrenaline-stimulated cAMP accumulation, while treatment with imipramine and the combination Li-imipramine decreased the noradrenaline-stimulated cAMP accumulation by 40%. The tissue content of calmodulin was found unaltered by all treatments.