X-Message-Number: 26675 Date: Thu, 21 Jul 2005 05:23:52 -0700 (PDT) From: Doug Skrecky <> Subject: inflammation and aging Exp Gerontol. 2005 May 31; [Epub ahead of print] Aging is characterized by a profound reduction in anti-inflammatory lipoxin A(4) levels. Ongoing low-grade chronic inflammation represents a pathogenetic background for age-related diseases. In this report, we tested the hypothesis that endogenous anti-inflammatory mechanisms may become less efficient with age, resulting in increased susceptibility to inflammatory disorders. Using previously validated ELISA assays, we evaluated urinary levels of the anti-inflammatory, pro-resolution, arachidonic acid (AA) metabolite, lipoxin (LX)A(4) and of the pro-inflammatory cysteinyl leukotrienes (cysLTs) in volunteers aged from 26 to over 100 years. (i) LXA(4) excretion was decreased in elderly people, resulting in a profound unbalance of the LXA(4)/cysLTs ratio, which may be considered an index of the endogenous anti-inflammatory potential. A significant inverse correlation was denoted between age and the LXA(4)/cysLTs ratio (rho=-0.41, P=0.0026). We conclude that aging is associated with a switch in arachidonic acid metabolism that prevents formation of key 'stop signals' of the inflammatory reaction. This may contribute to promote the development of disease in elderly. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=26675