392627.fig.004
Figure 4: Comparison of the dilative effect of tanshinone IIA on vasoconstriction induced by phenylephrine (10 nmol l−1) in the presence of endothelium (closed circle) or not (open circle). +, presence; –, absence. The preparation of isolated aortic rings from male SHR was described in Section 2. Data (mean ± SD) were obtained from eight experiments.