Fig. 6.

β₂AR-induced stress model in male myocytes. a, Contractile responses to β-adrenergic receptor stimulation by increasing concentration of isoproterenol (ISO) (n = 10 cells/4 mice) (b), Effect of epinephrine (Epi) stress on cardiac contraction. (n = 10 cells/4 mice). c Effects of stress on contraction amplitude abolished by β₂AR knockout (β₂KO) n = 10 cells/4 mice. d Effects of stress on Ca²⁺ transient amplitude were abolished by β₂KO, n = 10 cells/4 mice. ^*P < 0.05, ^**P < 0.01, and ^***P < 0.001. All data are presented as mean ± S.E.M