How could aortic arginase activity enhancement be involved in DOCA-salt hypertension?
This study was to examine whether the increase in aortic arginase activity observed in DOCA-salt hypertensive rats is involved in the mechanism of physiological hypertension by participating to vessel hypertrophy and/or to the impairment of endothelium-dependent relaxation to acethylcholine. We measured polyamine content and relaxation-response to acethylcholine in aortic rings isolated from control and DOCA-salt treated Sprague-Dawley rats after in vitro modification of arginase activity. Polyamine content was significantly increased in aorta from DOCA-salt hypertensive rats compared with controls. In the normotensive rats, the addition of L-valine (an inhibitor of arginase) decreased the relaxation response to acethylcholine whereas the addition of arginase increased the relaxation dependent response. On the contrary, in DOCA-salt hypertensive rats, the addition of L-valine or of arginase did not change the endothelium dependent relaxation. The results obtained suggest that the increase in aortic arginase activity in DOCA-salt hypertension could contribute to vascular hypertrophy but not to the impairment of endothelium-dependent relaxation.
Laboratoire de Physiologie, Pharmacologie et Nutrition Préventive Expérimentale, UFR Médecine-Pharmacie, Besançon, France.
S
S
Rodriguez
R
R
Schleiffer
F
F
Raul
L
L
Richert
A
A
Berthelot
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000201:enzymology* / Q000503:physiopathology; D001119:Arginase / Q000187:drug effects / Q000378:metabolism*; D001794:Blood Pressure / Q000187:drug effects; D006332:Cardiomegaly / Q000139:chemically induced / Q000378:metabolism; D003900:Desoxycorticosterone / Q000009:adverse effects*; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D006973:Hypertension / Q000139:chemically induced* / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D008955:Models, Cardiovascular; D009131:Muscle, Smooth, Vascular / Q000098:blood supply / Q000187:drug effects; D011073:Polyamines / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013223:Statistics as Topic; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
D011073:Polyamines; D014665:Vasodilator Agents; D003900:Desoxycorticosterone; D001119:Arginase; D000109:Acetylcholine