Increased RhoA translocation in aorta of diabetic rats.
OBJECTIVE
To analyze RhoA expression and activation in the aorta of diabetic rats.


METHODS
Male SD rats (n=70) were divided into 2 groups: the diabetic group and the control group. Diabetes was induced by intravenous injection of streptozotocin (55 mg/kg). The Rats were studied 3 weeks after the induction of diabetes. Western blotting was used to measure the expression and activation of Rho.


RESULTS
Heart rate was measured 24 h/d; it decreased by 58+/-13 beats/min in the diabetic rats. Isometric tension showed that the contraction of diabetic aorta was significantly reduced compared with that of control aorta when stimulated by KCl and serotonin. The relaxation of the diabetic aorta was reduced when stimulated by acetylcholine. An enhanced RhoA translocation in the aortic tissues of diabetic rats was determined by a 90% increase in membrane-bound RhoA, indicating that the activation of RhoA is markedly increased in the diabetic aorta.


CONCLUSIONS
Our data suggest that upregulated RhoA could be involved in the vascular dysfunction of diabetic rats.
Tang
Jiping
J
Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS 39216, USA. jipingtang@yahoo.com
Kusaka
Ikuyo
I
Massey
Amber R
AR
Rollins
Shadon
S
Zhang
John H
JH
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000378:metabolism* / Q000503:physiopathology; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000378:metabolism* / Q000503:physiopathology; D004789:Enzyme Activation; D006339:Heart Rate; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000503:physiopathology; D011189:Potassium Chloride / Q000494:pharmacology; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013311:Streptozocin; D015854:Up-Regulation; D020742:rhoA GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*
D012333:RNA, Messenger; D013311:Streptozocin; D011189:Potassium Chloride; D020742:rhoA GTP-Binding Protein; D000109:Acetylcholine