[Possible effects of endogenous hydrogen sulfide on aortic remodeling in hypertensive rats]

To explore the role and the possible mechanism of hydrogen sulfide (H(2)S) in modulating the remodeling of aorta of hypertensive rats.

Twenty-four male WKY rats were randomly divided into WKY control group, WKY+NaHS (H(2)S donor) group and WKY+PPG group. Another twenty-four male SHR rats at the age of 4 weeks were also divided into SHR control group, SHR+NaHS group and SHR+PPG group. SHR control and WKY control rats were injected with water, rats of SHR+NaHS group and WKY+ NaHS group were injected with NaHS, rats of SHR +PPG group and WKY +PPG group were injected with PPG each day. Five weeks later, the blood pressure was determined. The rat aortas were dyed with Weigert's Method. The morphometric parameters including outer radius, lumen radius and the media area were calculated by Leica workstation. The proliferation of smooth muscle cells was detected by immunohistochemical assay of PCNA.

The morphometric parameters of outer radius, lumen radius, medium area, and the ratio of wall thickness to lumen radius in SHR control rats were all higher than those of WKY control rats [outer radius (1 999+/-45) microm vs (1 790+/-96) microm, lumen radius(1 759+/-91) microm vs (1 636+/-94) microm, medium area (0.60+/-0.06) microm(2) vs (0.48+/-0.03) microm(2), and the ratio of wall thickness to lumen radius (0.066+/-0.006) vs (0.060+/-0.004)]. Expression of PCNA in aorta of SHR control rats was higher than that of WKY control rats too. Most of the structural remodeling parameters decreased in the rats of SHR+NaHS group [outer radius(1 864+/-66) microm, lumen radius (1 634+/-66) microm, medium area (0.53 +/-0.06) microm(2)] compared with those in rats of SHR control group. Expression of PCNA in aorta of SHR+NaHS control rats decreased compared with that of SHR control rats at the same time.

H(2)S is one of the key factors playing important roles in the modulation of the structural remodeling in aorta of SHR rats. Exogenous administration of H(2)S may attenuate the development of hypertensive rat aorta remodeling effectively.