Ecosinoids and Blood Vessel Structure

Ecosinoids and blood vessel structure We should, perhaps, pay more attention to the influence that ecosinoids have on blood vessel behavior and structure, as substances such as nonsteroidal antiinflammatory drugs (NSAIDs) and the so called selective cyclooxygenase 2 inhibitors are extensively employed by the population at large. In this issue of Vascular Health and Risk Management, Claridge and colleagues (2005) have reported a significant association of aortic wall stiffness with the use of NSAIDs. This interesting finding highlights the importance of the physiological and pathophysiological effects of ecosinoids on blood vessel behavior and function, as well as structure. The role of matrix metalloproteinase and plasminogen activator-plasmin systems have been the subject of considerable investigation, and it is now accepted that the remodeling of blood vessels is very much dependent upon degradation of the extracellular matrix (Bobik and Tkachuk 2003). The prostanoid that is thought to be involved in inducing the expression of metalloproteinase and plaminogen activator is prostaglandin (PG) E 2 (Khan et al 2004). Thus, the tendency for increased stiffness of blood vessels as a consequence of NSAID use could possibly result from a reduction in the levels of PG E 2 , perhaps in the vasculature. Based on experiments employing isolated rat aortic rings, indomethacin treatment in vitro produces a reduction in blood vessel compliances (Chin-Dusting et al 1988). Moreover, in animals fed a supplement of fish oil, aortic compliance ex vivo appears to be significantly reduced (Chin-Dusting et al 1988). In experimental animals, a diet high in fish oil results in the lowering of some naturally occurring ecosinoids (Hornstra et al 1981). Accordingly, it is possible that the reduction in biological activities of certain prostanoids may manifest as a significant reduction in aortic compliance ex vivo as observed in rats fed a high fish oil diet. This is not to suggest that the use of fish oil will result in a decrease in vascular compliance in vivo, as this issue remains controversial. However, whether, a similar mechanism is at play when aortic stiffness is increased clinically following the use of NSAIDs remains to be established. Certainly, the impact of NSAID use on blood vessel compliance needs a closer and in-depth investigation in humans. While it would be interesting to further pursue the notion of whether NSAIDs may also affect blood vessel stiffness in animals, it would also be of great interest to delineate the molecular nature of …