Proliferation of glial cells in vivo induced in the neural lobe of the ratpituitary by lithium

Lithium salts are widely used for treatment of psychiatric illness. Lithium also affects cell proliferation. During investigation of the effect of lit hium chloride on the central nervous system (CNS) of nephrectomized rats, w e noted numerous mitotic figures in the neural lobe of the pituitary. Morph ologic criteria established that the mitotic cells were astrocytes, the sup porting glial cells of the CNS, also known as pituicytes. Equimolar doses o f chlorides of chemically related cations (sodium, potassium, rubidium) had no such effect.