[Radix Astragali improves impaired endothelial dependent vasodilation in obese rat].
OBJECTIVE
To investigate the effects of Radix Astragali, a traditional Chinese medicine, on endothelium-dependent and non-dependent vasodilation in food-induced obese SD rats.


METHODS
Fifteen male Sprague-Dawley rats were divided into 3 groups. The control group (n=5) was fed with normal chow; The obese group (n=5) was fed with high fat chow; The Astragali group (n=5) was fed with high fat chow and Astragali in drinking water. At the end of six weeks, all rats were killed and heart blood samples were taken to assess serum triglyceride, total cholesterol, and free fat acid. The thoracic aortas rings were harvested and equilibrated in Krebs-Henseleit solution. To measure the endothelium-dependent relaxation, the aortas rings were constricted in response to norepinephrine. After a stable contraction plateau was reached, cumulative dose-response for relaxation to Acetylcholine (10(-8)-10(-4) mol/L) were obtained in each rings. Identical experiments were conducted with 10(-8)-10(-4) mol/L sodium nitroprusside as the endothelium independent vasorelaxting agent. Responses to vasodlilators were expressed as percentage relaxation in all preconstricted state.


RESULTS
The ratio of celiac fat and body weight in the obese rats was higher than in the controls. The levels of serum triglyceride, total cholesterol, and free fat acid were elevated in the Obese Group compared with the Control Group. The Astragali Group had lower triglyceride and free fat acid levels than the Obese Group. Compared with the rats with high-fat diet, the rats fed with Astragali lost about 32% of celiac fat. Acetylcholine (10(-8)-10(-4) mol/L) caused a concentration-dependent relaxation in all preconstricted aortic rings. Compared to the control group, maximal endothelium dependent relaxation in the obese group was impaired (P<0.05). In the Astragali group, the relaxation to acetylcholine was intermediate between control and obese group (P<0.05). Sodium nitroprusside (10(-8)-10(-4) mol/L) induced potent relaxation (endothelium independent relaxation) in all rat aortic rings that did not differ statistically between groups.


CONCLUSIONS
Astragalus has salutary effects on impaired endothelial dysfunction in the context of obesity.
Deng
Gang
G
Division of Endocrinology and Metabolism, West China Hospital, Sichuan University, Chengdu 610041, China.
Yu
Ye-Rong
YR
D000818:Animals; D027885:Astragalus propinquus; D004365:Drugs, Chinese Herbal / Q000627:therapeutic use; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology*; D045462:Endothelium-Dependent Relaxing Factors / Q000627:therapeutic use; D008297:Male; D009765:Obesity / Q000188:drug therapy* / Q000503:physiopathology; D008517:Phytotherapy; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D014664:Vasodilation / Q000187:drug effects*
D004365:Drugs, Chinese Herbal; D045462:Endothelium-Dependent Relaxing Factors