Abstract
It is reported that nicotine, one of the major tobacco tar components, increases the acetylcholine level in the brain. As nerve growth factor (NGF) is thought to promote the differentiation and maintenance of cholinergic neurons in the brain that are damaged in Alzheimer's disease (AD) by the increment of acetylcholine synthesis, we studied the relationship between nicotine and various tobacco tar components and the NGF synthesis/secretion in cultured astroglial cells. We found that multi-phenol compounds and nicotine increased the NGF content in the conditioned medium. NGF induced by nicotine had the same biological activity, molecular weight, and antigenicity as mouse βNGF. Especially, nicotine potentiated the NGF-mediated survival of sympathetic nerve cells. Thus, in addition to its known excitatory effect on the central nervous system, nicotine also has the additional effects of stimulating NGF synthesis/secretion of astroglial cells and potentiating NGF action. This increased NGF in the brain may serve to promote neuronal survival.
