Lau Y S, Lum B K
Arch Int Pharmacodyn Ther. 1983 Jan;261(1):36-50.
Studies were performed on the isolated bovine tracheal muscle preparation to assess the possible role of adenosine 3',5'-cyclic monophosphate (cyclic AMP) in adrenergically-induced smooth muscle relaxation. Isoproterenol, epinephrine, terbutaline and soterenol were found to relax the tracheal muscle and to increase its cyclic AMP content. The two events generally paralleled one another when analyzed in terms of dose-response and time-response relationships. Propranolol antagonized the relaxation and the increase in cyclic AMP produced by isoproterenol. However, other findings suggested that there may not be a cause and effect relationship between the biochemical and mechanical responses. Thus, salbutamol and carbuterol failed to increase muscle cyclic AMP even in concentrations which produced maximum relaxation. Additionally, butoxamine and H35/25 antagonized the biochemical response but had additive effects (instead of antagonistic effects) on the mechanical response to isoproterenol. Furthermore, it was observed that low concentrations of H35/25 produced tracheal muscle relaxation associated with an increase in tissue cyclic AMP; however, use of a high concentration of H35/25 paradoxically resulted in autoblockade of the increase in cyclic AMP but not the smooth muscle relaxation.
对分离出的牛气管肌肉制剂进行了研究，以评估3',5'-环磷酸腺苷（环磷酸腺苷）在肾上腺素能诱导的平滑肌松弛中可能发挥的作用。发现异丙肾上腺素、肾上腺素、特布他林和索特诺尔可使气管肌肉松弛并增加其环磷酸腺苷含量。从剂量反应和时间反应关系方面进行分析时，这两个事件通常相互平行。普萘洛尔可拮抗异丙肾上腺素引起的松弛作用及环磷酸腺苷增加。然而，其他研究结果表明，生化反应和机械反应之间可能不存在因果关系。因此，沙丁胺醇和卡布特罗即使在产生最大松弛作用的浓度下也未能增加肌肉环磷酸腺苷。此外，布托沙明和H35/25可拮抗生化反应，但对异丙肾上腺素的机械反应具有相加作用（而非拮抗作用）。此外，观察到低浓度的H35/25可使气管肌肉松弛，同时伴有组织环磷酸腺苷增加；然而，使用高浓度的H35/25却反常地导致环磷酸腺苷增加的自身阻断，但平滑肌松弛并未受到影响。
