Smooth Muscle Cells And Collagen In Intima Of High-lipid Diet Rabbit's With Constriction Of Abdominal Aorta

Objective The study was to investigate smooth muscle cells and collagen in intima of high-lipid diet rabbit's with constriction of abdominal aorta .Methods We divided New Zealand rabbits into common diet group(n=10) and high-lipid diet group(n=15). At the end of 8th and 28th week, We measured serum total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL). After 28 weeks, Ten rabbits of high-lipid diet group were referred to abdominal aortic constriction. Common diet group and five rabbits of high-lipid diet group were subjected to abdominal aortic sham operation. Then we divided them into 3 groups: high-lipid operation group(n=10), high-lipid sham operation group(n=5) and common sham operation group(n=10). These rabbits were then kept on for 4 weeks with a high-lipid diet and a common diet separately.We measured blood pressure in the proximate and distal of the constriction. Then took the abdominal aorta and fixed for paraffin sections. Sections were stained with hematoxylin—eosin and picro—siriusred and immunohistochemistry. The abdominal aortic morphological features, collagen and smooth muscle cells were studied separately.Results①TG,TC,LDL of high-lipid diet group were more than common diet group[(29.12±2.75 vs 1.69±0.44)mmol/L, (4.71±1.05 vs 1.28±0.41)mmol/L, (17.06±1.93 vs 1.56±0.48)mmol/L, P<0.05].②The blood pressure(BP) was higher in the proximate of abdominal aorta than that in the distance in various group. And BP in the proximate of constriction was higher in high-lipid operation group than that in high-lipid sham operation group[(11.20±0.70 vs 9.42±0.29)kPa, P<0.05], and lower in the distal of the constriction than that in high-lipid sham operation group[(6.99±0.79 vs 7.84±0.48)kPa, P<0.05].③The intima was thin and glossy in common sham operation group. There were a lot of foam cells in the intima of high-lipid operation group and high-lipid sham operation group. The intima was thicker in the proximate of constriction in high-lipid operation group than that in high-lipid sham operation group[(183.76±10.53 vs 164.59±4.9)μm, P< 0.05], and thinner in the distal than that in high-lipid sham operation group[(118.63±13.35 vs 136.84±6.28)μm, P<0.05].④Smooth muscle cells and collagen were more in the proximate of constriction in high-lipid operation group than those in high-lipid sham operation group[Smooth muscle cells: (0.23±0.01 vs 0.15±0.02)OD, collagen: (0.27±0.05 vs 0.18±0.01)OD, P<0.05], and less in the distal than those in high-lipid sham operation group[(0.06±0.03 vs 0.09±0.01)OD, (0.09±0.02 vs 0.13±0.01)OD, P<0.05].Conclusion The blood pressure was higher in the proximate of constriction in high-lipid operation rabbit's abdominal aorta, and the intima was thicker, smooth muscle cells and collagen were more. With the blood pressure gradual declining, All the above were less in the distal of constriction.