Uzuki Mitsuru, Yamakage Michiaki, Fujimura Naoyuki, Namiki Akiyoshi
Department of Anesthesiology, Sapporo Medical University School of Medicine, South 1, West 16, Sapporo 060-8543, Japan.
J Anesth. 2006;20(2):145-8. doi: 10.1007/s00540-005-0373-6.
Intraabdominal sepsis can lead to acute respiratory failure, and concomitant diaphragmatic dysfunction may be aggravated by sepsis-induced airway hyperreactivity. We previously reported that isoproterenol, a nonselective beta-adrenoceptor agonist, increased diaphragmatic contractility and accelerated recovery from fatigue during sepsis. The purpose of this study was to demonstrate the direct inotropic effect of a potent bronchodilator and beta(2)-selective adrenoceptor agonist, procaterol, on fatigued diaphragmatic contractility in an intraabdominal septic model. Rats were divided into two groups: a cecal ligation and perforation (CLP) group and a sham group. CLP was performed in the CLP group whereas laparotomy alone was performed in the sham group. The left hemidiaphragm was removed at 16 h after the operation. The diaphragmatic tissues were exposed to procaterol (10(-8)-10(-6) M), and muscle contractility was assessed. Intracellular cyclic AMP levels were also measured in the CLP model. Procaterol caused an upward shift in the force-frequency curves in the CLP group whereas it had no effect on the curves in the sham group. Procaterol significantly increased cyclic AMP levels in the CLP model. We conclude that the potent bronchodilator procaterol had a direct and positive inotropic effect on the diaphragm in an intraabdominal septic model.
腹腔内脓毒症可导致急性呼吸衰竭，而脓毒症诱导的气道高反应性可能会加重膈肌功能障碍。我们之前报道过，非选择性β-肾上腺素能受体激动剂异丙肾上腺素可增加脓毒症期间的膈肌收缩力并加速疲劳恢复。本研究的目的是在腹腔脓毒症模型中证明强效支气管扩张剂和β₂选择性肾上腺素能受体激动剂丙卡特罗对疲劳膈肌收缩力的直接正性肌力作用。将大鼠分为两组：盲肠结扎穿孔（CLP）组和假手术组。CLP组进行盲肠结扎穿孔，而假手术组仅进行剖腹手术。术后16小时切除左半膈肌。将膈肌组织暴露于丙卡特罗（10⁻⁸ - 10⁻⁶ M），并评估肌肉收缩力。在CLP模型中还测量了细胞内环磷酸腺苷（cAMP）水平。丙卡特罗使CLP组的力-频率曲线向上移位，而对假手术组的曲线无影响。丙卡特罗显著提高了CLP模型中的cAMP水平。我们得出结论，强效支气管扩张剂丙卡特罗在腹腔脓毒症模型中对膈肌具有直接的正性肌力作用。
