Angiotensin II in apoptotic lung injury: potential role in meconium aspiration syndrome.

Meconium aspiration injures a number of cell types in the lung, most notably airway and alveolar epithelial lining cells. Recent data show that at least some of the cell death induced by meconium occurs by apoptosis, and therefore has the potential for pharmacologic inhibition through the use of apoptosis blockers or other strategies. Related work in adult animal models of lung injury has shown that apoptosis of lung epithelial cells induces a local (that is, entirely lung tissue specific) renin-angiotensin system (RAS(L)). Furthermore, this inducible RAS(L) is required for the apoptotic response and affects other adjacent cell types through the release of angiotensin II and related peptides. This manuscript reviews the published data supporting this viewpoint as well as more recent works that suggest the involvement of a RAS(L) in the perinatal lung damage associated with meconium aspiration syndrome (MAS). The implications of these findings regarding their potential for the clinical management of MAS are also discussed.