Topical zinc applications promote wound healing and epithelialization. “Leaky” MDCKII epithelia exposed to apical ZnCl2 (10 mM) showed a time-dependent increase (t 0.5 22.2 ± 2.7 min) of transepithelial resistance (R t) from 82.3 ± 2.4 Ω cm2 to 1,551 ± 225.6 Ω cm2; the increase was dose-dependent, being observed at 3 mM but not at 1 mM. Basal Zn2+ applications also increased epithelial resistance (at 10 mM to 323 ± 225.6 Ω cm2). The linear current–voltage relationship in control epithelia changed after apical 10 mM ZnCl2 to show rectification. Voltage deflections resulting from inward currents showed time-dependent relaxation (basal potential difference (p.d.)-positive), with outward currents being time-independent. Cation selectivity was tested after apical ZnCl2 elevated resistance; both the NaCl:mannitol (basal replacement) dilution p.d. and the choline:Na bi-ionic p.d. decreased (PNa/PCl from 4.9 to 2.3 and PNa/Pcholine from 3.8 to 2.1, respectively). Transepithelial paracellular basal to apical 45Ca fluxes increased approximately twofold when driven by a basal positive Na:NMDG bi-ionic p.d., but with basal 10 mM ZnCl2, 45Ca fluxes decreased approximately twofold. Neither ZO-1 nor occludin distribution was altered after ~2-h exposure to apical 10 mM ZnCl2. However, claudin-2, though present at the tight junction, increased within the cell. Increased epithelial barrier resistance by Zn2+ is due to modification of the paracellular pathway, most probably by multiple mechanisms.
The Journal of Membrane Biology – Springer Journals
Published: Nov 6, 2010
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera