Kaneda Takeharu, Kanakura Harue, Yamamoto Masahiro, Tajima Tsuyoshi, Urakawa Norimoto, Shimizu Kazumasa
Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Nippon Veterinary and Life Science University, Musashino, Tokyo, Japan.
J Vet Med Sci. 2009 Sep;71(9):1209-16. doi: 10.1292/jvms.71.1209.
A high-K(+), Na(+)-deficient (isosmotic 154 mM K(+) and 0 mM Na(+); I-154 K(+)) solution induced contraction followed by gradual relaxation of the smooth muscles of the porcine trachea, while hyperosmotic addition of 65 mM KCl (H-65 K(+)) induced a large sustained contraction. The I-154 K(+) solution also induced a sustained increase in Ca(2+) level. Decreases in muscle tension and increases in cellular water content were both prevented by the addition of sucrose or NaCl in the porcine trachea. An additional application of phloridzin inhibited recoveries of I-154 K(+) solution by addition of NaCl in the porcine trachea. Addition of pyruvate or oxaloacetate recovered the I-154 K(+) solution-induced relaxation in the porcine trachea. Although application of I-154 K(+) solution did not affect PCr and ATP contents in the bovine trachea, the solution induced a gradual decrease of PCr content in the porcine trachea. Moreover, application of pyruvate or oxaloacetate recovered the I-154 K(+) solution-induced decreases of PCr content in the porcine trachea. Phloridzin inhibited H-65 K(+)-induced contraction in porcine, but not in bovine trachea. In conclusion, the I-154 K(+) solution-induced relaxation in the porcine trachea is probably due to swelling of cells and inhibition of glucose utilization. Moreover, the inhibition of glucose utilization in I-154 K(+) medium in porcine trachea is different from that of bovine trachea.
高钾、低钠（等渗，154 mM钾离子和0 mM钠离子；I-154 K(+)）溶液可引起猪气管平滑肌收缩，随后逐渐舒张，而高渗添加65 mM氯化钾（H-65 K(+)）则引起强烈的持续性收缩。I-154 K(+)溶液还可引起细胞内钙离子（Ca(2+)）水平持续升高。在猪气管中添加蔗糖或氯化钠可防止肌肉张力降低和细胞含水量增加。额外应用根皮苷可抑制在猪气管中添加氯化钠后I-154 K(+)溶液引起的恢复。添加丙酮酸或草酰乙酸可恢复I-154 K(+)溶液在猪气管中引起的舒张。虽然应用I-154 K(+)溶液不影响牛气管中的磷酸肌酸（PCr）和三磷酸腺苷（ATP）含量，但该溶液可引起猪气管中PCr含量逐渐降低。此外，应用丙酮酸或草酰乙酸可恢复I-154 K(+)溶液在猪气管中引起的PCr含量降低。根皮苷可抑制猪气管中H-65 K(+)引起的收缩，但对牛气管无此作用。总之，I-154 K(+)溶液在猪气管中引起的舒张可能是由于细胞肿胀和葡萄糖利用受抑制。此外，猪气管中I-154 K(+)培养基中葡萄糖利用的抑制与牛气管不同。
