Wiesmann W, Sinha S, Yates J, Klahr S
Am J Physiol. 1978 Dec;235(6):F564-9. doi: 10.1152/ajprenal.1978.235.6.F564.
Acetylcholine and carbamylcholine (carbachol) inhibited sodium transport across the toad bladder. This effect was blocked by atropine. Carbachol increased the uptake of 45Ca by isolated toad bladder epithelial cells. This increased 45Ca uptake was blocked by atropine, pentobarbital, or lanthanum chloride. The inhibitory effect of cholinergic agents on sodium transport was dependent on external calcium concentration and was abolished by decreasing external calcium from 2 to 0.2 mM or by agents (pentobarbital, lanthanum chloride) which prevent the movement of calcium into cells. Carbachol increased modestly, but significantly, the levels of cyclic GMP in isolated toad bladder epithelial cells. This effect was blocked by atropine. Whether the decrease in sodium transport produced by cholinergic agents is the result of increased intracytoplasmic calcium levels, increased cyclic GMP levels, or a combination of both remains to be established.
乙酰胆碱和氨甲酰胆碱（卡巴胆碱）抑制钠通过蟾蜍膀胱的转运。这种作用被阿托品阻断。卡巴胆碱增加了离体蟾蜍膀胱上皮细胞对45Ca的摄取。这种增加的45Ca摄取被阿托品、戊巴比妥或氯化镧阻断。胆碱能药物对钠转运的抑制作用取决于细胞外钙浓度，当细胞外钙浓度从2 mM降至0.2 mM或使用阻止钙进入细胞的药物（戊巴比妥、氯化镧）时，这种抑制作用就会消失。卡巴胆碱适度但显著地增加了离体蟾蜍膀胱上皮细胞中环鸟苷酸（cGMP）的水平。这种作用被阿托品阻断。胆碱能药物引起的钠转运减少是细胞内钙水平升高、环鸟苷酸水平升高还是两者共同作用的结果，仍有待确定。
