Seidel C L, Schnarr R L, Sparks H V
Am J Physiol. 1975 Aug;229(2):265-9. doi: 10.1152/ajplegacy.1975.229.2.265.
The purpose of this study was to test the hypothesis that the mechanical response of coronary smooth muscle following adrenergic receptor stimulation was mediated by changes in cyclic AMP content. Dibutyryl cyclic AMP caused relaxation of coronary artery strips. Aminophyline caused relaxation and a 254% elevation of cyclic AMP content (P less than 0.005). Phenylephrine caused contraction but no significant change in cyclic AMP content (P greater than 0.4). Epinephrine alone caused contraction and a 99% elevation of cyclic AMP content (P less than 0.001). The alpha blocker, phentolamine, reversed the mechanicaal response to epinephrine, but it did not significantly (P greater than 0.15) reduce the effect of epinephrine on cyclic AMP content. Propranolol enhanced the contractile response to epinephrine and attenuated the epinephrine-induced increase in cyclic AMP content. These results suggest that the contraction of coronary arteries associated with alpha-receptor stimulation is not mediated by changes in cyclic AMP content; however, relaxation associated with beta-receptor stimulation may be mediated by an increase in cyclic AMP content.
肾上腺素能受体刺激后冠状动脉平滑肌的机械反应是由环磷酸腺苷（cAMP）含量的变化介导的。二丁酰环磷酸腺苷可使冠状动脉条带松弛。氨茶碱可使冠状动脉条带松弛，且使环磷酸腺苷含量升高254%（P<0.005）。去氧肾上腺素可引起收缩，但环磷酸腺苷含量无显著变化（P>0.4）。单独使用肾上腺素可引起收缩，且使环磷酸腺苷含量升高99%（P<0.001）。α受体阻滞剂酚妥拉明可逆转对肾上腺素的机械反应，但对肾上腺素对环磷酸腺苷含量的影响无显著降低作用（P>0.15）。普萘洛尔增强了对肾上腺素的收缩反应，并减弱了肾上腺素诱导的环磷酸腺苷含量增加。这些结果表明，与α受体刺激相关的冠状动脉收缩不是由环磷酸腺苷含量的变化介导的；然而，与β受体刺激相关的松弛可能是由环磷酸腺苷含量的增加介导的。
