The role of MMP's in aortic rupture in the Friesian horse

Abstract

Aortic ruptures are seen quite frequently in the Friesian horse compared with Warmblood horses. Because of the increased prevalence and the characteristic findings in pathologic examination it is suggestive that aberrant collagen is the underlying cause for rupturing the aorta. In human, mice and rats similar aorta pathologies were found and they were proven to be connected with an increased matrix metalloproteinase (MMP) level. Because MMP’s have demolishing influence on collagen it is thought that increased levels could lead to weakening of the aortic wall with a bigger risk of rupture as result. To prove this theory samples from different parts of the Friesian and Warmblood aortas were taken and the levels of MMP’s were determined with the aid of fluorescence. Finallythe results of this experiment were compared with each other. As a control group also deep flexor tendons of the distal limbs were included in this research. Only in the 1/5 part of the aorta the MMP-levels were increased in Friesian horses, apparently this is not enough evidence for MMP’s being the cause of aortic rupture. In the other samples the levels of MMP were higher in Warmblood horses as they were in Friesians, which might be suggestive that Friesians have a lower MMP-level in general which could lead to less renewal of tissue.