Angiotensin (1-7) (ASP-ARG-VAL-TYR-ILE-HIS-PRO) is a synthetic heptapeptide identical to endogenous angiotensin-(1-7) , inhibits purified canine ACE activity (IC50=0.65 μM) with vasodilator and antiproliferative activities.

ACE:0.65 μM (IC50)

ANG-(1-7)显著减轻了ANG II引起的大鼠心脏肥大和周血管纤维化。这些ANG-(1-7)的效果在培养的心肌细胞中得到了证实，其中ANG-(1-7)显著减轻了ANG II引导的细胞大小增加[1]。

Ang-(1-7)处理减轻了心房有效不应期的缩短和心房颤动诱导能力水平的增加。免疫组化和Western blotting结果显示，起搏组存在交感神经过度增生，而Ang-(1-7)减轻了交感神经的增殖。Ang-(1-7)缓解了起搏引起的酪氨酸羟化酶及神经生长因子mRNA表达水平的增加[2]。

Cultured cardiomyocytes were treated with PBS (control), ANG II (100 nM), ANG-(1–7) (100 nM), ANG II + ANG-(1–7), ANG II + ANG-(1–7) + A779 (10 μM), ANG II + ANG-(1–7) + Sirt3 short hairpin (sh)RNA, lentiviral particles (1 × 10^6 TU) containing a Sirt3 shRNA viral vector, or ANG II + Mito-TEMPO (0.1 μM) for 24 h. Each treatment was performed in triplicate wells. Monoclonal anti-α-sarcomeric actin antibody was used for identification and measurement of cardiomyocytes via immunofluorescence staining. Cells were fixed in methanol at ?10°C and washed with fresh washing solution (0.1% Triton X-100 in PBS) three times. After preincubation with 3% BSA for 20 min, cells were incubated with primary antibody, which was diluted to 1:100 with PBS containing 3% BSA, overnight at 4°C. After three washings with the washing solution, cells were incubated with fluorescence-conjugated anti-mouse IgG (1:500 diluted in PBS) for 1 h at room temperature. Photographic images of cardiomyocytes were taken with a fluorescence microscope. Image-analysis software was used to measure the cell surface area of cardiomyocytes that were positively stained for sarcomeric actin. Variations in cell size were expressed as relative cell surface area versus the control. At least 50 cells in each dish were randomly selected for surface area analysis[1].

Eighteen dogs were randomly assigned to sham group, pacing group and Ang-(1-7) group. Rapid atrial pacing was maintained for 14 days in the pacing and Ang-(1-7) groups. Ang-(1-7) was administered intravenously in the Ang-(1-7) group. The atrial effective refractory period and atrial fibrillation inducibility level were measured at baseline and under sympathetic nerve stimulation after 14 days of measurement. The atrial sympathetic nerves labeled with tyrosine hydroxylase were detected using immunohistochemistry and Western blotting, and tyrosine hydroxylase and nerve growth factor mRNA levels were measured by reverse transcription polymerase chain reaction[2].