New insights into the role of zinc in the respiratory epithelium

Over the past 30 years, many researchers have demonstrated the critical rol e of zinc (Zn), a group IIb metal, in diverse physiological processes, such as growth and development. maintenance and priming of the immune system, a nd tissue repair. This review will discuss aspects of Zn physiology and its possible beneficial role in the respiratory epithelium. Here wee have deta iled the mechanisms by which Zn diversely acts as: (i) an antioxidant: (ii) an organelle stabilizer: (iii) an anti-apopototic agent: (iv) an important cofactor for DNA synthesis; (v) a vital component for wound healing, and ( vi) an anti-inflammatory agent. This paper will also review studies from th e authors' laboratory concerning the first attempts to map Zn in the respir atory epithelium and to elucidate its role in regulating caspase-3 activate d apoptosis. We propose that Zn. being a major dietary anti-oxidant has a p rotective role for the airway epithelium against oxyradicals and other noxi ous agents. Zn may therefore have important implications for asthma and oth er inflammatory diseases where the physical barrier is vulnerable and compr omised.