Endogenous aldosterone contributes to acute angiotensin II-stimulated plasminogen activator inhibitor-1 and preproendothelin-1 expression in heart but not aorta.
To test the hypothesis that angiotensin (Ang) II induces profibrotic gene expression through endogenous aldosterone, we measured the effect of 4 h infusion (600 ng/kg x min) of Ang II on tissue mRNA expression of plasminogen activator inhibitor 1 (PAI-1), preproendothelin-1 (ppET-1), TGF-beta, and osteopontin in wild-type (WT), aldosterone synthase-deficient (AS(-/-)), and AS(-/-) mice treated with aldosterone (either 500 ng/d for 7 d or 250 ng as a concurrent 4 h infusion). Ang II increased aldosterone in WT (P < 0.001) but not in AS(-/-) mice. Aldosterone (7 d) normalized basal aldosterone concentrations in AS(-/-) mice; however, there was no further effect of Ang II on aldosterone (P = NS). Basal cardiac and aortic PAI-1 and ppET-1 expression were similar in WT and AS(-/-) mice. Ang II-stimulated PAI-1 (P < 0.001) and ppET-1 expression (P = 0.01) was diminished in the heart of AS(-/-) mice; treatment with aldosterone for 4 h or 7 d restored PAI-1 and ppET-1 mRNA responsiveness to Ang II in the heart. Ang II increased PAI-1 (P = 0.01) expression in the aorta of AS(-/-) as well as WT mice. In the kidney, basal PAI-1, ppET-1, and TGF-beta mRNA expression was increased in AS(-/-) compared with WT mice and correlated with plasma renin activity. Ang II did not stimulate osteopontin or TGF-beta expression in the heart or kidney. Endogenous aldosterone contributes to the acute stimulatory effect of Ang II on PAI-1 and ppET-1 mRNA expression in the heart; renin activity correlates with basal profibrotic gene expression in the kidney.
Luther
James M
JM
Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6602, USA. james.luther@vanderbilt.edu
Wang
Zuofei
Z
Ma
Ji
J
Makhanova
Natalia
N
Kim
Hyung-Suk
HS
Brown
Nancy J
NJ
D000450:Aldosterone / Q000097:blood / Q000494:pharmacology / Q000502:physiology*; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001011:Aorta / Q000187:drug effects* / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D019405:Cytochrome P-450 CYP11B2 / Q000235:genetics; D004347:Drug Interactions; D019332:Endothelin-1 / Q000235:genetics* / Q000378:metabolism; D006321:Heart / Q000187:drug effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009206:Myocardium / Q000378:metabolism; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics* / Q000378:metabolism; D044140:Receptor, Angiotensin, Type 1 / Q000378:metabolism; D013997:Time Factors; D015854:Up-Regulation / Q000187:drug effects
D019332:Endothelin-1; D017395:Plasminogen Activator Inhibitor 1; D044140:Receptor, Angiotensin, Type 1; D000804:Angiotensin II; D000450:Aldosterone; D019405:Cytochrome P-450 CYP11B2