Putney J W, Parod R J
J Pharmacol Exp Ther. 1978 May;205(2):449-58.
Carbachol (10(-4) M), a cholinergic secretagogue, significantly increased the ouabain-sensitive uptake of 86Rb by rat parotid gland slices. This effect was blocked by the omission of Ca from the bathing medium. When extracellular Na was decreased from 125 to 5 mM, the effect of carbachol was reversed (86Rb uptake was significantly decreased). Increasing intracellular Na (by incubation in medium lacking K) produced a significant stimulation of 86Rb influx. A role for Na in the response was suspected, and so the metabolism, of 22Na by the slices was characterized. The 60-minute distribution of 22Na could be described by three kinetic components; one extracellular (0.315 ml/g, tau = 1.94 minutes) and two intracellular (0.075 ml/g, tau = 7.63 minutes and 0.017 ml/g, tau = 58.4 minutes). Carbachol enhanced the uptake of 22Na into the intracellular components (primarily the 7.63-minute component). The increased uptake of 22Na required Ca in the bathing medium. These observations could be explained by assuming that cholinergic receptor activation stimulates Ca influx which in turn enhances Na uptake. The resulting elevated intracellular Na acts to stimulate activity of the Na,K pump.
卡巴胆碱（10⁻⁴ M），一种胆碱能促分泌剂，可显著增加大鼠腮腺切片对哇巴因敏感的⁸⁶Rb摄取。这种效应可被去除浴液中的Ca所阻断。当细胞外Na从125 mM降至5 mM时，卡巴胆碱的效应逆转（⁸⁶Rb摄取显著降低）。增加细胞内Na（通过在无K的培养基中孵育）可显著刺激⁸⁶Rb内流。怀疑Na在该反应中起作用，因此对切片中²²Na的代谢进行了表征。²²Na的60分钟分布可用三个动力学成分来描述；一个细胞外成分（0.315 ml/g，τ = 1.94分钟）和两个细胞内成分（0.075 ml/g，τ = 7.63分钟和0.017 ml/g，τ = 58.4分钟）。卡巴胆碱增强了²²Na向细胞内成分（主要是7.63分钟成分）的摄取。²²Na摄取增加需要浴液中有Ca。这些观察结果可以通过假设胆碱能受体激活刺激Ca内流来解释，而Ca内流反过来又增强Na摄取。由此导致的细胞内Na升高作用于刺激Na,K泵的活性。
