Abstract
Aldosterone infusion with high salt treatment induces cardiac fibrosis in rats. Aldosterone enhanced angiotensin II (Ang II) has been shown to induce proliferation and increase the expression of Ang II receptor mRNA and Ang II binding in vitro. To investigate the role of Ang II type 1a receptor (AT1aR) in aldosterone-and-salt (Ald-NaCi)-induced cardiac fibrosis, we subcutaneously infused aldosterone (0.15 μg/h) and 1% NaCl (Ald-NaCl) into AT1aR knockout mice (AT1aR-KO) or wild type mice (Wt). To examine the role of NaCl on cardiac fibrosis, we gave some of the aldosterone-treated AT1aR-KO tap water (Ald-H2O). Ald-NaCl treatment increased systolic blood pressure and induced cardiac hypertrophy in both strains, whereas there were no such changes in the mice without aldosterone. Severe cardiac fibrosis was seen in Ald-NaCl-treated AT1aR-KO and not in Ald-NaCl-treated Wt. In contrast, Ald-NaCl-treated Wt with co-administration of an active metabolite of olmesartan, the AT1aR antagonist (10 mg/kg/day) did not show cardiac fibrosis. Na+/H+ exchanger, and Na+-K+ ATPase α2 subunit mRNA were decreased in AT1aR-KO. Na+/Ca2+ exchanger mRNA was lower in AT1aR-KO than Wt and was decreased by Ald-NaCl in both strains. Phosphorylation of epidermal growth factor receptor and extracellular signal-regulated kinase was increased by Ald-NaCl treatment in AT1aR-KO. Connective tissue growth factor (CTGF) and osteopontin mRNA were increased and accumulation of CTGF proteins was seen in the hearts of Ald-NaCl-treated AT1aR-KO. Ald-H2O-treated AT1aR-KO did not show any cardiac fibrosis. These results suggest that Ald-NaCl-induced cardiac fibrosis required both aldosterone and salt. Because cardiac fibrosis was exaggerated in Ald-NaCl-treated AT1aR-KO but was not seen in Wt treated with Ald-NaCl and olmesartan, AT1aR may not play a primary role in progression of cardiac fibrosis by Ald-NaCl, and gene disruption of AT1aR may have some implications in this model.
| Original language | English |
|---|---|
| Pages (from-to) | 979-989 |
| Number of pages | 11 |
| Journal | Hypertension Research |
| Volume | 30 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - Oct 1 2007 |
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All Science Journal Classification (ASJC) codes
- Internal Medicine
- Physiology
- Cardiology and Cardiovascular Medicine
Cite this
Aldosterone-and-salt-induced cardiac fibrosis is independent from angiotensin II type 1a receptor signaling in mice. / Kagiyama, Shuntaro; Matsumura, Kiyoshi; Fukuhara, Masayo; Sakagami, Kanae; Fujii, Koji; Iida, Mitsuo.
In: Hypertension Research, Vol. 30, No. 10, 01.10.2007, p. 979-989.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Aldosterone-and-salt-induced cardiac fibrosis is independent from angiotensin II type 1a receptor signaling in mice
AU - Kagiyama, Shuntaro
AU - Matsumura, Kiyoshi
AU - Fukuhara, Masayo
AU - Sakagami, Kanae
AU - Fujii, Koji
AU - Iida, Mitsuo
PY - 2007/10/1
Y1 - 2007/10/1
N2 - Aldosterone infusion with high salt treatment induces cardiac fibrosis in rats. Aldosterone enhanced angiotensin II (Ang II) has been shown to induce proliferation and increase the expression of Ang II receptor mRNA and Ang II binding in vitro. To investigate the role of Ang II type 1a receptor (AT1aR) in aldosterone-and-salt (Ald-NaCi)-induced cardiac fibrosis, we subcutaneously infused aldosterone (0.15 μg/h) and 1% NaCl (Ald-NaCl) into AT1aR knockout mice (AT1aR-KO) or wild type mice (Wt). To examine the role of NaCl on cardiac fibrosis, we gave some of the aldosterone-treated AT1aR-KO tap water (Ald-H2O). Ald-NaCl treatment increased systolic blood pressure and induced cardiac hypertrophy in both strains, whereas there were no such changes in the mice without aldosterone. Severe cardiac fibrosis was seen in Ald-NaCl-treated AT1aR-KO and not in Ald-NaCl-treated Wt. In contrast, Ald-NaCl-treated Wt with co-administration of an active metabolite of olmesartan, the AT1aR antagonist (10 mg/kg/day) did not show cardiac fibrosis. Na+/H+ exchanger, and Na+-K+ ATPase α2 subunit mRNA were decreased in AT1aR-KO. Na+/Ca2+ exchanger mRNA was lower in AT1aR-KO than Wt and was decreased by Ald-NaCl in both strains. Phosphorylation of epidermal growth factor receptor and extracellular signal-regulated kinase was increased by Ald-NaCl treatment in AT1aR-KO. Connective tissue growth factor (CTGF) and osteopontin mRNA were increased and accumulation of CTGF proteins was seen in the hearts of Ald-NaCl-treated AT1aR-KO. Ald-H2O-treated AT1aR-KO did not show any cardiac fibrosis. These results suggest that Ald-NaCl-induced cardiac fibrosis required both aldosterone and salt. Because cardiac fibrosis was exaggerated in Ald-NaCl-treated AT1aR-KO but was not seen in Wt treated with Ald-NaCl and olmesartan, AT1aR may not play a primary role in progression of cardiac fibrosis by Ald-NaCl, and gene disruption of AT1aR may have some implications in this model.
AB - Aldosterone infusion with high salt treatment induces cardiac fibrosis in rats. Aldosterone enhanced angiotensin II (Ang II) has been shown to induce proliferation and increase the expression of Ang II receptor mRNA and Ang II binding in vitro. To investigate the role of Ang II type 1a receptor (AT1aR) in aldosterone-and-salt (Ald-NaCi)-induced cardiac fibrosis, we subcutaneously infused aldosterone (0.15 μg/h) and 1% NaCl (Ald-NaCl) into AT1aR knockout mice (AT1aR-KO) or wild type mice (Wt). To examine the role of NaCl on cardiac fibrosis, we gave some of the aldosterone-treated AT1aR-KO tap water (Ald-H2O). Ald-NaCl treatment increased systolic blood pressure and induced cardiac hypertrophy in both strains, whereas there were no such changes in the mice without aldosterone. Severe cardiac fibrosis was seen in Ald-NaCl-treated AT1aR-KO and not in Ald-NaCl-treated Wt. In contrast, Ald-NaCl-treated Wt with co-administration of an active metabolite of olmesartan, the AT1aR antagonist (10 mg/kg/day) did not show cardiac fibrosis. Na+/H+ exchanger, and Na+-K+ ATPase α2 subunit mRNA were decreased in AT1aR-KO. Na+/Ca2+ exchanger mRNA was lower in AT1aR-KO than Wt and was decreased by Ald-NaCl in both strains. Phosphorylation of epidermal growth factor receptor and extracellular signal-regulated kinase was increased by Ald-NaCl treatment in AT1aR-KO. Connective tissue growth factor (CTGF) and osteopontin mRNA were increased and accumulation of CTGF proteins was seen in the hearts of Ald-NaCl-treated AT1aR-KO. Ald-H2O-treated AT1aR-KO did not show any cardiac fibrosis. These results suggest that Ald-NaCl-induced cardiac fibrosis required both aldosterone and salt. Because cardiac fibrosis was exaggerated in Ald-NaCl-treated AT1aR-KO but was not seen in Wt treated with Ald-NaCl and olmesartan, AT1aR may not play a primary role in progression of cardiac fibrosis by Ald-NaCl, and gene disruption of AT1aR may have some implications in this model.
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U2 - 10.1291/hypres.30.979
DO - 10.1291/hypres.30.979
M3 - Article
C2 - 18049031
AN - SCOPUS:36248951504
VL - 30
SP - 979
EP - 989
JO - Hypertension Research
JF - Hypertension Research
SN - 0916-9636
IS - 10
ER -