ACTIVATION OF CULTURED GLIAL-CELLS BY AMITRIPTYLINE AND PLATELET-ACTIVATING-FACTOR

The activation of glial cells in culture by exposure to chemicals proc eeds through two stages. The first stage appears to be an activation o f oligodendroglial (0%) proliferation and increased activities of 2'3' -cyclic 3'-phosphodiesterase (CNP). This stage frequently leads to a s econd stage, which is characterized by a transformation of microglia t o actively phagocyting cells with increased 5'-nucleotidase (5'-NT) ac tivity. Compounds of heavy metals induce OG proliferation and activati on of CNP, but do not activate microglia. In contrast amitriptyline (A T) is a potent activator of microglia cells and stimulates 5'-NT. Expo sure of the cells to platelet activated factor (PAF) or AT for 2, 5, 7 or 12 days revealed different effects on the release of prostaglandin E(2) emphasizing the fact that the cells have specific receptors for FAG but not for AT.