Fig. (4) Tianma increased the contractile force and elasticity of the thoracic aortic rings. Comparison of maximum contractile force developed in response to 80 mM K+ and increasing concentrations (CRCs) of PE in aortic rings from tianma-treated rats and controls. The isolated endothelium-intact arterial rings were studied with the endothelium left intact and data are presented as tension (g) per milligram tissue wet weight (g/mg wet weight of aorta). Values represent an average of 2x8 individual experiments. An asterisk indicates a significant difference from the control value (*P < 0.05 compared to the control group).