Effects of tea polyphenols on cardiac function and myocardial ultrastructure in rats after repeated +Gz stress.
Objective. To observe the effects of tea polyphenols (TP) on cardiac function and myocardial ultrastructure in rats after repeated +10 Gz stress. Method. Twenty four male Wistar rats were randomly divided into three groups (n=8 each): group A (control), group B (+10 Gz), group C (+Gz with TP). Group B and C were repeatedly exposed to +10 Gz (each for 30 s, onset rate about 0.5 G/s, 3 times/d with +1 Gz 1 min intervals, 3 d/wk, 4 weeks in total), but group A was only submitted to +1 Gz. TP (200 mg kg-1) was given orally to group C about 1 h prior to the +Gz experiment, and distilled water was given to group A and B. Function of isolated rat working hearts and myocardial ultrastructure were observed. Result. A significant decrease of left ventricular systolic pressure (LVSP) and injury of myocardial structure in rats were demonstrated after repeated +10 Gz stress. But TP could remarkably elevate the LVSP and improve myocardial ultrastructural injury in +10 Gz stressed rats. Conclusion. These results indicated that repeated high G exposure may produce cardiac structural and functional injuries in rats which might be partly related to free radical metabolism; and antioxidant TP had significant protective effects on the hearts of +Gz stressed rats.
Zhan
H
H
Institute of Aviation Medicine, Beijing.
Dong
H J
HJ
Xin
Y M
YM
Tang
G X
GX
D000054:Acceleration; D000284:Administration, Oral; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D005419:Flavonoids; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D018471:Hypergravity; D008297:Male; D009206:Myocardium / Q000648:ultrastructure*; D010636:Phenols / Q000008:administration & dosage / Q000494:pharmacology*; D011108:Polymers / Q000008:administration & dosage / Q000494:pharmacology*; D059808:Polyphenols; D051381:Rats; D017208:Rats, Wistar; D013662:Tea / Q000737:chemistry*
D005419:Flavonoids; D010636:Phenols; D011108:Polymers; D059808:Polyphenols; D013662:Tea