| Objective:To study early stage lung lesions in rabbits induced by hyperlipidemia and the possible mechanism of injury, and the effect of hawthorn extract combined with Gypenosides.Methods:Male Japanese white rabbits 50, weight 1.9-2.3kg, randomly selected 10 as the normal rabbits fed with normal rabbit pellets, and the remaining 40 were given high fat diet (1% cholesterol,5% egg yolk powder,5% lard,89% of the normal diet).Four weeks later, serum total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) were measured. Select rabbits with serum TC 6 times higher than the mean level of normal rabbits as the successful hyperlipidemia model, divided them into 3 groups of 10 each:model control group, Xuezhikang group, hawthorn leaf extract and Gypenosides combination group(Below referred to as SJ group); at the same time, select 10 normal rabbits as the normal group. Then, continue feeding the rabbits as the method mentioned above; at the meanwhile, Xuezhikang group and combination group were given Xuezhikang powder, hawthorn leaf extract and Gypenosides mixture. At the end of the eighth week, serum lipids was measureded again, and got lung tissue of rabbits to do HE staining, VG collagen fiber staining, Weigert elastic fiber staining, and immunohistochemical detection of Angâ…¡; at the same time SOD, MDA, NOS of lung homogenates were measured.Results:1. Interstitial pneumonia and the small artery intima eccentric or diffuse thickening occurs in some rabbits of the model group, Xuezhikang group and SJ group. Among the four groups, the results of VG collagen fibers staining show that collagen fibers of lung tissue in integrated optical density (IOD) were found no difference in change (P>0.05), the results of weigert elastic fiber staining show that pulmonary artery WT%(wall thickness in the percentage of external diameter) were also found no difference in change (P>0.05).2. compared with the normal group, the content of TC, TG, LDL-C, HDL-C in serum of model group and Xuezhikang group were still significantly higher (P<0.01), while HDL-C/TC were significantly decreased (P<0.01); but compared with the model group, TC, TG, LDL-C were significantly decreased in Xuezhikang group and SJ group (P <0.05), while HDL-C/TC was increased (P<0.05).3. Compared with normal group, the content of MDA in lung tissue of rabbits of model control group slightly increased (P<0.05), while SOD activity slightly declined (P<0.05). Compared with model control group, Xuezhikang group, SJ group decreased slightly in MDA content (P<0.05), while SOD activity increased (P<0.05).4. Compared with normal group, the activity of TNOS and cNOS in lung tissue of rabbits of model control group slightly declined (P>0.05), while iNOS slightly increased (P>0.05). Howener, Compared with normal group, the ratio of iNOS and cNOS of model control group slightly increased (P<0.05); and Xuezhikang group and SJ group significantly higher than model control group in the ratio of iNOS and cNOS (P<0.05).5. Compared with normal group, model control group showed a stronger brown positive reaction, the positive expression of Angâ…¡significantly increased, the same with Xuezhikang group and SJ group (P<0.05); Compared with model control group, the expression of Angâ…¡in Xuezhikang group and SJ group showed a little weaker (P<0.05).Conclusion:1. Hyperlipidemia can cause lung tissue injury in rabbits, the main sites of injury are pulmonary interstitial and vascular.2. Hyperlipidemia can induce the changes of SOD activity and MDA content in rabbit lung tissue, and affect the expression of NOS and Angâ…¡,suggesting that the mechanism of lung injury may be related to lipid peroxidation and NOS, Angâ…¡abnormal expressio.3. Lipid lowering drugs-Xuezhikang and mixture of hawthorn leaf extract and Gypenosides can improve serum lipid levels in hyperlipidemia rabbits, reduce lipid peroxidation and regulate NOS, Angâ…¡expression in lung tissue, to improve lung injury caused by hyperlipidemia. |
PDF Full Text Request