Park M K, Hayashi S, Robotham J L
Proc Soc Exp Biol Med. 1984 Nov;177(2):283-9. doi: 10.3181/00379727-177-41944.
Cooling of isolated guinea pig tracheal smooth muscle from 38 to 28 degrees C over 2.25 min produced a transient contraction followed by sustained relaxation. The cooling-induced contraction was blocked either by pretreatment with ouabain at concentrations of 10(-5) M or greater or by substitution of normal physiological salt solution with K-free solution. In contrast, the contractile response to cooling was not inhibited by pretreatment with phentolamine (10(-5) M), atropine (10(-5) M), tetrodotoxin (3 X 10(-7) M), diphenhydramine (10(-5) M), cromolyn sodium (10(-3) M), indomethacin (3 X 10(-7) M), nifedipine (10(-7) M), or verapamil (3 X 10(-6) M). Addition of NaHCO3 to the bath during cooling, preventing a change in pH of the physiological salt solution, did not affect the cooling-induced contraction. It is concluded that cooling of isolated guinea pig trachea produces a transient ouabain-sensitive contraction, and that the data suggest the contraction is mediated by inhibition of Na-K-ATPase in the smooth muscle rather than through neuronal stimulation or chemical mediator release.
在2.25分钟内将分离的豚鼠气管平滑肌从38℃冷却至28℃会产生短暂收缩，随后是持续舒张。冷却诱导的收缩可被浓度为10⁻⁵M或更高的哇巴因预处理阻断，或通过用无钾溶液替代正常生理盐溶液来阻断。相比之下，酚妥拉明（10⁻⁵M）、阿托品（10⁻⁵M）、河豚毒素（3×10⁻⁷M）、苯海拉明（10⁻⁵M）、色甘酸钠（10⁻³M）、吲哚美辛（3×10⁻⁷M）、硝苯地平（10⁻⁷M）或维拉帕米（3×10⁻⁶M）预处理均不抑制对冷却的收缩反应。在冷却期间向浴槽中添加NaHCO₃，防止生理盐溶液pH值变化，并不影响冷却诱导的收缩。得出的结论是，分离的豚鼠气管冷却会产生短暂的对哇巴因敏感的收缩，并且数据表明该收缩是由平滑肌中Na-K-ATP酶的抑制介导的，而不是通过神经元刺激或化学介质释放介导的。
