• Title/Summary/Keyword: active transepithelial ion transport

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Regulation of depth and composition of airway surface liquid

  • J. H. Widdicombe;S. J. Bastacky;D. X.Y. Wu;Lee, C. Y.
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1996.04a
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    • pp.119-130
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    • 1996
  • We review the factors which regulate the depth and composition of the human airway surface liquid (ASL). These include secretion from airway submucosal glands, ion and fluid transport across the surface epithelium, goblet cell discharge, surface tension and transepithelial gradients in osmotic and hydrostatic pressure. We describe recent experiments in which we have used low temperature scanning electron microscopy of rapidly frozen specimens to detect changes in depth of ASL in response to submucosal gland stimulation. We also present preliminary data in which X-ray microanalysis of frozen specimens has been used to determine the elemental composition of ASL.

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Effect of Ginseng Alcohol Extract on Short-Circuit Current Across the Frog Skin (인삼 알콜 추출물이 개구리 피부를 통한 short circuit current에 미치는 영향)

  • Lee, Joong-Woo;Kim, Hee-Joong;Kang, Doo-Hee
    • The Korean Journal of Physiology
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    • v.10 no.1
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    • pp.35-40
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    • 1976
  • In an attempt to examine the effect of ginseng on sodium transport across the biological membrane, we have studied effects of ginseng alcohol extract on the short-circuit current(SCC) and the $Na^+-K^+$-activated ATPase activity in isolated frog skin preparations. 1. Ginseng alcohol extract applied to the mucosal surface of the frog skin significantly increased SCC at low concentration($1{\sim}10mg%$) but decreased SCC at higher concentration($50{\sim}250mg%$). 2. Similarly, when the drug was added to the serosal bathing medium, the SCC was stimulated at low doses($5{\sim}25mg%$) and inhibibited at high doses($50{\sim}250mg%$). 3. $Na^+-K^+$-activated ATPase activity of the frog skin epidermal homogenate was significantly inhibited by ginseng alcohol extract, the effect being proportional to the concentration of the drug in the incubation mixture. These results may suggest that a low dose of ginseng alcohol extrat enhances the transepithelial sodium transport probably by increasing the permeability of outer membrane of the transporting cell to sodium ion, whereas a high dose of drug reduces the sodium transport primarly by inhibiting $Na^+-K^+$ ATPase mediated active transport step.

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