Peptide factors in proliferation, differentiation, and viability of the cells of mammalian nervous system

Some aspects of the involvement of two classes of regulatory peptides in pr oliferation, differentiation, and viability of nerve and glial cells are an alyzed on the example of two peptides: Semax (Met-Glu-His-Phe-Pro-Gly-Pro), an analog of the N-terminal fragment of ACTH (4-10), and Taftsine (Thr-Lys -Pro-Arg). Semax at 0.1 to 10.0 mu M caused a 1.5-3.0-fold increase in the survival of nerve cells in the rat embryo brain cell cultures and had no ef fect on the proliferation of glial cells. The same concentrations of Taftsi ne had only a slight effect on proliferation of glial cells, but at 0.01 an d 1.0 mu M it stimulated axon growth in reaggregated neuroglial cultures of the rat spinal cord. The possible mechanisms of the peptide effect on mamm alian glial and nerve cells are discussed.