人红细胞膜泡中环磷酸腺苷的转运

Cyclic AMP transport in human erythrocyte ghosts.

作者信息

Holman G D

出版信息

Biochim Biophys Acta. 1978 Mar 21;508(1):174-83. doi: 10.1016/0005-2736(78)90199-2.

PMID:204349

Abstract

10(-5) M cyclic AMP has high permeability in human erythrocyte ghosts (p = 0.061-10(-6) cm.s-1). Saturation of influx and efflux occurs. Koizt = 4.43 mM. Voizt = 259.6 micron.min-1-Kiozt = 0.475 micron. Viozt = 28.3 micron.min-1 at 30 degrees C. Equilibrium exchange entry of cyclic AMP has similar kinetics to zero trans influx, though the system does show counterflow. Cytochalasin B is an apparent competitive inhibitor of cyclic AMP exit. (Ki = 3.9.10(-7) M). Control experiments indicated that cyclic AMP remains intact during incubation with red blood cell ghosts and is contained within the intravesicular space during the transport experiments.

摘要

10⁻⁵M环磷酸腺苷（cAMP）在人红细胞血影中具有高渗透性（渗透率p = 0.061 - 10⁻⁶cm·s⁻¹）。存在流入和流出的饱和现象。Koizt = 4.43 mM。在30℃时，Voizt = 259.6微米·分钟⁻¹，Kiozt = 0.475微米，Viozt = 28.3微米·分钟⁻¹。环磷酸腺苷的平衡交换进入与零转流入具有相似的动力学，尽管该系统确实显示出逆流。细胞松弛素B是环磷酸腺苷流出的一种明显竞争性抑制剂（Ki = 3.9×10⁻⁷M）。对照实验表明，环磷酸腺苷在与红细胞血影孵育期间保持完整，并且在转运实验期间包含在囊泡内空间中。