[Suppression of abdominal aortic aneurysm by hydrogen through chemokine-like factor1]

To explore the mechanism of hydrogen on the intervention of abdominal aortic aneurysm (AAA).

Healthy male Sprague-Dawley rats were divided into AAA group and AAA intervention group (saturated hydrogen saline administered intraperitoneally once daily). AAA was induced by infiltration of abdominal aorta with 0.5 mol/L calcium chloride. Twenty-eight days later, the diameter of the aorta was measured, and the aortic tissue was exercised for histological examination. The protein location and expression of rCklf1 and matrix metalloproteinase 2 (MMP2) in aortic tissue were observed by immunohistochemistry staining. The mRNA expression of rCklf1 and MMP2 underwent real-time PCR.

Dilatation rate of abdominal aorta of AAA group and AAA intervention group was (174 ± 21)% and [(82 ± 23)%, P < 0.01] respectively. The tissue relative mRNA expression of rCklf1 was 5.10 ± 0.33 and 1.34 ± 0.29 (P < 0.01). The relative mRNA expression of MMP2 was 10.28 ± 0.35 and 2.40 ± 0.97 (P < 0.01). The proteins expression of rCklf1 and MMP2 were mainly increased in the damaged elastic fibers of AAA group. Compared with AAA group, the AAA intervention group had less significant positive expression of rCklf1 and MMP2 protein, infiltration of inflammation, destruction and degradation of elastic fibers.

Hydrogen which may contribute to reduce rCklf1 expression prevents infiltration of inflammation and expression of MMP2 thus decreasing destruction and degradation of elastic fibers, therefore ameliorates development of AAA.