The multiple faces of nicotine and its implications in tissue and wound repair.

Nicotine, one of the thousands of chemicals in cigarette smoke has a highly debated effect on cell proliferation and tissue healing. Recent studies documented its pro-angiogenesis effects by stimulating endothelial cell alpha7-non-neronal nicotinic acetyl choline receptors (alpha7 N-nACHR). It is well known that individuals who smoke or have diabetes experience impaired wound healing although for different reasons. This review evaluates several current studies relating to nicotine's ability to mediate cellular activation, migration and angiogenesis in attempts to correlate these data with nicotine's ability to repair wounds in ischaemic tissue. While its beneficial effects are still under investigation, important findings regarding nicotine's acceleration of atherosclerosis, tumor angiogenesis, cell proliferation e and resistance to apoptosis put its systemic use into question. Based on the good and bad sides of nicotine, it is recommended to restrict its utility to local applications.