an increasing trendP = 0.065
The contraction of the aortic rings in response to high KCl from the older Spr −/− mice (2.57 ± 0.41 mN) showed an increasing trend compared with that in the wild‐type mice of the same age (1.69 ± 0.17 mN) ( P = 0.065, n = 10, Student's t ‐test).