Fig. 4
Vascular reactivity parameters. Shown are acetylcholine (ACh, 10−9–10−4 mol L−1) responses in the coronary artery precontracted with 5-hydroxytryptamine (5-HT) and the areas under the concentration–response curves (AUCs) for Ach (a) from Wistar Kyoto rats (WKY group), spontaneously hypertensive rats (SHRs; SHR group), SHRs treated with dronedarone (SHR-D group), and SHRs treated with hydralazine (SHR-H group). Relaxation responses are expressed as the percent reductions from the 5-HT–precontracted state. 5-HT (5-HT, 10−9–3 × 10−5 mol L−1) responses in the coronary artery and the areas under the concentration–response curve (AUCs) for 5-HT (b) from the WKY, SHR, SHR-D, and SHR-H groups are also shown. Contraction responses with 5-HT are expressed as the percentages of the maximum response of the arteries to K+-KHS. N = 9 rats for each experimental group. The data are expressed as the mean ± SEM. Statistically significant differences among the WKY, SHR, SHR-D, and SHR-H groups are shown (∗P < 0.05 versus WKY; ∗∗P < 0.01 versus WKY; ∗∗∗P < 0.001 versus WKY; #P < 0.05 versus SHR; ##P < 0.01 versus SHR; §P < 0.05 versus SHR-D; §§P < 0.01 versus SHR-D)
