细胞外钠离子对去极化子宫中异丙肾上腺素诱导的环磷酸腺苷（cAMP）水平的影响。

Effect of extracellular Na on isoproterenol-induced cAMP levels in depolarized uterus.

作者信息

Meisheri K D, Tenner T E, McNeill J H

出版信息

Eur J Pharmacol. 1978 Dec 15;53(1):9-20. doi: 10.1016/0014-2999(78)90262-5.

Abstract

In the present study, the absence of a quantitative correlation between isoproterenol induced relaxation of uterine strips and tissue cAMP levels was demonstrated by using three depolarizing media: 127 mM KCl (0 NaCl), 47.5 mM KCl (NaCl), and 47.5 mM KCl (80 mM NaCl). While the degree of relaxation by isoproterenol was similar in all three media, isoproterenol (10(-4)M) increased cAMP by 100% in Na+ free depolarizing media, by 337% in Na+ containing depolarizing medium and by 600% in normal non-depolarizing medium. After pretreatment of the tissue with 10(-5) M D-600, 10(-4) M isoproterenol increased cAMP levels by 600% in all three depolarzing media. Studies using 10(-8) M isoproterenol produced qualitatively similar results. cGMP levels did not change significantly in any of the above studies. Na+ appears to be producing its effect on isoproterenol induced increase in cAMP levels indirectly by reducing the increase in intracellular Ca2+ concentration known to occur with depolarization.

摘要

在本研究中，通过使用三种去极化介质：127 mM KCl（0 NaCl）、47.5 mM KCl（NaCl）和47.5 mM KCl（80 mM NaCl），证明了异丙肾上腺素诱导子宫条松弛与组织环磷酸腺苷（cAMP）水平之间不存在定量相关性。虽然在所有三种介质中异丙肾上腺素引起的松弛程度相似，但异丙肾上腺素（10⁻⁴M）在无钠去极化介质中使cAMP增加100%，在含钠去极化介质中增加337%，在正常非去极化介质中增加600%。用10⁻⁵M D - 600预处理组织后，10⁻⁴M异丙肾上腺素在所有三种去极化介质中使cAMP水平增加600%。使用10⁻⁸M异丙肾上腺素的研究产生了定性相似的结果。在上述任何研究中，环磷酸鸟苷（cGMP）水平均无显著变化。钠离子似乎通过减少已知因去极化而发生的细胞内钙离子浓度增加，间接对异丙肾上腺素诱导的cAMP水平升高产生影响。