Nicotine is widely used as an aid to smoking cessation and is currently evaluated to treat non-smoking related disorders such as Alzheimer and ulcerative colitis, where it is deemed to have no major long-term side effects. But in June Nature Medicine, Christopher Heeschen and colleagues from Stanford University School of Medicine, California found anatomic and functional evidence that nicotine induces angiogenesis and increases the growth of tumour and atheroma in association with increased neovascularization.

Working on four different murine models, Heeschen et al. found that nicotine increased endothelial cell growth and tube formation in vitro, and accelerated fibrovascular growth in vivo. In addition, nicotine enhanced lung tumour growth in association with an increase in lesion vascularity via nicotinic acetylcholine receptors. These effects occurred at nicotine concentrations that are pathophysiologically relevant (Nature Med 2001, 7:833-839).

The authors speculated that endothelial production of nitric oxide, prostacyclin and vascular endothelial growth factor might have a role in the angiogenesis.

"Stimulation of angiogenesis by nicotine raises many questions about its mechanism of action and use in therapy" wrote Rakesh Jain from Harvard Medical School in an accompanying 'News and Views' article.