姥鲨（白斑角鲨）直肠腺切片中的细胞溶质组成及钾效应

Cell solute composition and potassium effects in slices of the rectal gland of the dogfish shark (Squalus acanthias).

作者信息

Kleinzeller A, Forrest J N, Cha C J, Goldstein J, Booz G

出版信息

J Comp Physiol B. 1985;155(2):145-53. doi: 10.1007/BF00685207.

Abstract

Cell solute composition and apparent intracellular ionic concentrations (subscript i) were determined in rectal gland slices of the dogfish shark (Squalus acanthias). On aerobic incubation in elasmobranch Ringer's at 15 degrees C, the steady state values were: Ki+, 151 mM, close to its apparent electrochemical equilibrium; Cai2+, 1.7 mM; Mgi2+, 7.5 mM; Cl1-, 97 mM (maintained against its electrochemical potential gradient); the sum (Nai+ + Ki+) was about 66 meq/kg cell water lower than in the medium. Of free amino acids, only the effectively impermeable anionic taurine (32 mM) and glutamate (3.7 mM) significantly contribute to the Donnan system. Variations of the Ringer's K+ concentrations, or the presence of 0.5 mM ouabain, demonstrated the permeability of the cell membrane to na+, K+, and Cl-. Cell volume changes: 0.5 mM ouabain produced a gradual swelling and ionic changes consistent with an inhibition of the sodium pump. In high-K+ media the cells swelled massively and the membrane depolarized. A linear relationship between cell volume changes and the Nernst potential for K+ was found. These properties are consistent with a pump-and-leak system for cell volume maintenance. The K+ -induced cell swelling was found to be reversible on transfer of the tissue to regular Ringer's. The extrusion of cell water was associated with an influx of Na+ into, and an efflux of K+ from, the cells (both fluxes down-hill), as well as extrusion of Cl- against its concentration gradient.2+

摘要

在角鲨（白斑角鲨）的直肠腺切片中测定了细胞溶质组成和表观细胞内离子浓度（下标i）。在15℃下于板鳃类林格氏液中进行需氧孵育时，稳态值如下：K⁺i为151 mM，接近其表观电化学平衡；Ca²⁺i为1.7 mM；Mg²⁺i为7.5 mM；Cl⁻i为97 mM（逆着其电化学势梯度维持）；（Na⁺i + K⁺i）的总和比培养基中的低约66 meq/kg细胞水。在游离氨基酸中，只有有效不可渗透的阴离子牛磺酸（32 mM）和谷氨酸（3.7 mM）对唐南系统有显著贡献。林格氏液中K⁺浓度的变化或0.5 mM哇巴因的存在证明了细胞膜对Na⁺、K⁺和Cl⁻的通透性。细胞体积变化：0.5 mM哇巴因导致逐渐肿胀和离子变化，这与钠泵的抑制一致。在高K⁺培养基中，细胞大量肿胀且膜去极化。发现细胞体积变化与K⁺能斯特电位之间存在线性关系。这些特性与用于维持细胞体积的泵 - 漏系统一致。发现K⁺诱导的细胞肿胀在将组织转移到常规林格氏液后是可逆的。细胞水的排出与Na⁺流入细胞、K⁺流出细胞（两者通量均为下坡）以及Cl⁻逆着其浓度梯度排出有关。