Naftalin R J, Pedley K C
Department of Physiology, King's College London, England.
FEBS Lett. 1990 Jan 29;260(2):187-94. doi: 10.1016/0014-5793(90)80100-w.
Extracellular accumulation of Na+ detected by video-enhanced microscopic imaging of the impermeant fluorescent probe SBFI confirms the view that colonic crypts produce a hypertonic ascorbate ca 1000 mOsm.kg-1, thereby generating a large osmotic pressure across the crypt wall. This creates a high fluid tension within the crypt lumen, sufficient to dehydrate faeces. When bathed in Tyrode the SBFI.Na+ fluorescence indicates a [Na+] ca 750 mM within the interstitial space of metabolizing rat descending colon. There is no evidence of interstitial Na+ accumulation in octanol (2 mM) or in rabbit colon incubated with 1.0 mM ouabain and no evidence of Na+ secretion via the crypt lumen during absorption.
通过对不可渗透的荧光探针SBFI进行视频增强显微镜成像检测到的细胞外Na⁺积累，证实了结肠隐窝产生约1000 mOsm.kg⁻¹的高渗抗坏血酸盐的观点，从而在隐窝壁上产生较大的渗透压。这在隐窝腔内产生了高流体张力，足以使粪便脱水。当用台氏液浸泡时，SBFI-Na⁺荧光表明在代谢中的大鼠降结肠的间质空间内[Na⁺]约为750 mM。在辛醇（2 mM）中或用1.0 mM哇巴因孵育的兔结肠中没有间质Na⁺积累的证据，并且在吸收过程中没有通过隐窝腔分泌Na⁺的证据。
