二磺酸芪对龟膀胱中氯离子和碳酸氢根离子转运的影响。

The effects of a disulphonic stilbene on chloride and bicarbonate transport in the turtle bladder.

Brodsky W A, Durham J, Ehrenspeck G

J Physiol. 1979 Feb;287:559-73. doi: 10.1113/jphysiol.1979.sp012677.

Abstract

In turtle bladders bathed by Na-free media containing Cl and HCO3, the mucosa is electropositive to the serosa. Serosally applied 4-acetamido-4'-isothiocyano-2,2'-disulphonic stilbene (SITS) reduces the p.d. and Isc by 100%, and reduces the rate of net Cl reabsorption in some bladders but not in others. 2. In the absence of exogenous HCO2 (Cl present), SITS reduces the p.d. and Isc by 100%, and reduces the rate of mucosal acidification by 80%; net Cl reabsorption is not detectable under these HCO3-free bathing conditions. 3. In the absence of exogenous Cl (HCO3, present), the mucosa is also electropositive to the serosa and serosally applied SITS reverses the orientation of the p.d. and Isc so that the mucosa becomes electronegative to the serosa. 4. This constitutes sufficient evidence for the active, electrogenic secretion of an anion, probably HCO3. These data are explained by an analogue of discrete, electrogenic pumps and paths for the reabsorption of Na, Cl, and HCO3, and the secretion of HCO3.

摘要

在由含氯和碳酸氢根的无钠介质灌注的龟膀胱中，黏膜相对于浆膜呈电正性。浆膜侧施加4-乙酰氨基-4'-异硫氰基-2,2'-二磺酸芪（SITS）可使跨膜电位（p.d.）和短路电流（Isc）降低100%，并使一些膀胱中氯离子的净重吸收率降低，但在另一些膀胱中则不然。2. 在没有外源性碳酸氢根（存在氯离子）的情况下，SITS可使跨膜电位和短路电流降低100%，并使黏膜酸化速率降低80%；在这些无碳酸氢根的灌注条件下，无法检测到氯离子的净重吸收。3. 在没有外源性氯离子（存在碳酸氢根）的情况下，黏膜相对于浆膜也呈电正性，浆膜侧施加SITS可使跨膜电位和短路电流的方向反转，从而使黏膜相对于浆膜呈电负性。4. 这构成了一种阴离子（可能是碳酸氢根）进行主动、电生性分泌的充分证据。这些数据可以通过类似于离散的、电生性的钠、氯和碳酸氢根重吸收泵及途径以及碳酸氢根分泌泵及途径来解释。