Fig. 3

The effect of bradykinin 1 receptor (B1R) blockade on body weight, blood pressure, total serum IgG, and autoantibody levels. Twenty-eight 4-month-old MRL/lpr mice were divided into a control group (n = 14) and a treatment group (n = 14). The B1R antagonist SSR240612 was dissolved in water containing dimethyl sulfoxide (DMSO) to make a final concentration of 1.5 mg/mL in 0.9% DMSO. Mice in the treatment group were administered 10 mg/kg per day SSR240612 by gavage every other day, whereas the mice in the control group received 10 mg/kg per day 0.9% DMSO by gavage every other day. No significant difference was seen in the ratio of spleen weight to body weight between the control group and the treatment group (a). In addition, B1R blockade was associated with a decreased ratio of kidney weight to body weight compared with the control group (a, P = 0.0409). MRL/lpr mice showed higher blood pressure levels at 12 weeks than baseline. B1R blockade lowered the mean artery blood pressure compared with the control group (P = 0.0357, b). B1R blockade lowered total serum IgG levels after 12 weeks of treatment (c, P = <0.0001). Serum IgG anti-dsDNA, IgG anti-histone, and IgM anti-histone decreased significantly in the treatment group compared with the control group (d, P = 0.025; g, P = 0.024, k, P = 0.042). B1R blockade didn't affect IgG anti-ssDNA or IgM anti-ssDNA (e, i). A non-parametric Mann–Whitney test was used to analyze the data. Taking into account the missing values (for deceased animals), the corrected P values were as follows: a: P <0.006 for spleen/body ratio and P <0.0002 for kidney/body ratio, b (mean BP): P <0.0001, c (IgG): P <0.001; d (anti-DNA): P <0.0001; f (anti-histone): P <0.0001), g (anti-histone/DNA): P <0.0015; h (IgM anti-dsDNA): P <0.0026; j (IgM anti-histone): P <0.0002, and the remaining significance levels were unaltered