Effects of long-term enalapril and losartan therapy of hypertension on cardiovascular aldosterone.
BACKGROUND
Plasma aldosterone escape is found during long-term angiotensin-converting enzyme inhibitor therapy. Evidence for aldosterone production in cardiovascular tissues raised the question of whether or not aldosterone escape occurs in these tissues.


METHODS
Spontaneously hypertensive rats were treated with enalapril (20 mg/kg/day) and losartan (50 mg/kg/day) for 20 weeks; untreated spontaneously hypertensive and Wistar rats were used as positive and normal controls, respectively. Ex vivo mesenteric artery and heart perfusion, high-performance liquid chromatography, and radioimmunoassay for aldosterone were performed.


RESULTS
The results showed that enalapril failed to significantly inhibit aldosterone production in mesenteric artery, myocardium and plasma. Losartan significantly inhibited aldosterone production to that of Wistar rats in the mesenteric artery, myocardium and plasma.


CONCLUSIONS
This study provides the first evidence that long-term angiotensin-converting enzyme inhibition therapy induces aldosterone escape in hypertensive cardiovascular tissues, and angiotensin II subtype 1 receptor antagonist does not induce aldosterone escape in mesenteric artery, myocardium and plasma of spontaneously hypertensive rats.
Li
S
S
Department of Cardiology, Nan Fang Hospital, The First Military Medical University, Guangzhou, PR China.
Wu
P
P
Zhong
S
S
Guo
Z
Z
Lai
W
W
Zhang
Y
Y
Liang
X
X
Xiu
J
J
Li
J
J
Liu
Y
Y
D000450:Aldosterone / Q000097:blood / Q000378:metabolism*; D000804:Angiotensin II / Q000097:blood; D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage* / Q000627:therapeutic use; D000818:Animals; D000959:Antihypertensive Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects; D002319:Cardiovascular System / Q000378:metabolism*; D004334:Drug Administration Schedule; D004656:Enalapril / Q000008:administration & dosage* / Q000627:therapeutic use; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D019808:Losartan / Q000008:administration & dosage* / Q000627:therapeutic use; D008638:Mesenteric Arteries / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D051381:Rats; D011918:Rats, Inbred SHR; D017208:Rats, Wistar; D044140:Receptor, Angiotensin, Type 1; D012016:Reference Values
D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D044140:Receptor, Angiotensin, Type 1; D000804:Angiotensin II; D000450:Aldosterone; D004656:Enalapril; D019808:Losartan