Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Deafness and imbalance associated with inactivation of the secretory Na-K-2Cl co-transporter


Deafness can result from a variety of gene defects1. Some genes involved in the physiology of hearing encode membrane transporters that regulate the ionic composition of the fluid bathing the inner ear. The endolymph is an extracellular fluid with an atypical composition that resembles the intracellular milieu, high in K+ and low in Na+. Recent studies have emphasized the prominent role of K+ channels in endolymph secretion2,3,4 and mechanical transduction5. Coupled electroneutral transport of Na+, K+ and Cl- is mediated by two isoforms of the Na-K-2Cl co-transporter: the absorptive isoform BSC1 (also called NKCC2, encoded by Slc12a1 in mouse) that is exclusively expressed in kidney; and BSC2/NKCC1 (encoded by Slc12a2 in mouse), the secretory isoform which has a wider pattern of expression including epithelia, muscle cells, neurons and red blood cells6,7. These co-transporters share 57% homology at the amino acid level8,9,10,11 and are pharmacologically inhibited by loop diuretics. There is functional12,13,14 and histochemical15,16,17 evidence for the presence of the secretory isoform of the Na-K-2Cl co-transporter in gerbil, rat and rabbit inner ear. We disrupted mouse Slc12a2 and report here that Slc12a2-/- mice are deaf and exhibit classic shaker/waltzer behaviour, indicative of inner-ear defects. We localized the co-transporter to key secreting epithelia of the mouse inner ear and show that absence of functional co-transporter leads to structural damages in the inner ear consistent with a decrease in endolymph secretion.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Disruption of Slc12a2.
Figure 2: Thionin staining of cochlea.
Figure 3: High-power magnification of hair cells of the organ of Corti.
Figure 4: Immunolocalization of Na-K-2Cl co-transporter in mouse inner ear.


  1. Petit, C. Genes responsible for human hereditary deafness: symphony of a thousand. Nature Genet. 14, 385–391 (1996).

    Article  CAS  Google Scholar 

  2. Schulze-Bahr, E. et al. KCNE1 mutations causes Jervell and Lange-Nielsen syndrome. Nature Genet. 17, 267–268 (1997).

    Article  CAS  Google Scholar 

  3. Neyroud, N. et al. A novel mutation in the potassium channel gene KVLQT1 causes the Jervell and Lange-Nielsen cardioauditory syndrome. Nature Genet. 15, 186–189 (1997).

    Article  CAS  Google Scholar 

  4. Vetter, D.E. et al. Inner ear defects induced by null mutation of the isk gene. Neuron 17, 1251–1264 (1996).

    Article  CAS  Google Scholar 

  5. Kubisch, C. et al. KCNQ4, a novel potassium channel expressed in sensory outer hair cells, is mutated in dominant deafness. Cell 96, 437–446 (1999).

    Article  CAS  Google Scholar 

  6. Mount, D.B. et al. The electroneutral cation-chloride cotransporters. J. Exp. Biol. 201, 2091–2102 (1998).

    CAS  PubMed  Google Scholar 

  7. Haas, M. & Forbush, B. III The Na-K-Cl cotransporters. J. Bioenerg. Biomembr. 30, 161–172 (1998).

    Article  CAS  Google Scholar 

  8. Gamba, G. et al. Molecular cloning, primary structure, and characterization of two members of the mammalian electroneutral sodium-(potassium)-chloride cotransporter family expressed in kidney. J. Biol. Chem. 269, 17713–17722 (1994).

    CAS  PubMed  Google Scholar 

  9. Simon, D.B. et al. Bartter's syndrome, hypokalaemic alkalosis with hypercalciuria, is caused by mutations in the Na-K-2Cl cotransporter NKCC2. Nature Genet. 13, 183–188 (1996).

    Article  CAS  Google Scholar 

  10. Delpire, E., Rauchman, M.I., Beier, D.R., Hebert, S.C. & Gullans, S.R. Molecular cloning and chromosome localization of a putative basolateral Na-K-2Cl cotransporter from mouse inner medullary collecting duct (mIMCD-3) cells. J. Biol. Chem. 269, 25677–25683 (1994).

    CAS  PubMed  Google Scholar 

  11. Payne, J.A. et al. Primary structure, functional expression, and chromosome localization of the bumetanide sensitive Na-K-Cl cotransporter in human colon. J. Biol. Chem. 270, 17977–17985 (1995).

    Article  CAS  Google Scholar 

  12. Marcus, N.Y. & Marcus, D.C. Potassium secretion by nonsensory region of gerbil utricle in vitro. Am. J. Physiol. 253, F613–F621 (1987).

    Article  CAS  Google Scholar 

  13. Marcus, D.C., Marcus, N.Y. & Greger, R. Sidedness of action of loop diuretics and ouabain on nonsensory cells of utricle: a micro-Ussing chamber for inner ear tissues. Hearing Res. 30, 55–64 (1987).

    Article  CAS  Google Scholar 

  14. Shiga, N. & Wangemann, P. Ion selectivity of volume regulatory mechanisms present during a hypoosmotic challenge in vestibular dark cells. Biochim. Biophys. Acta 1240, 48–54 (1995).

    Article  Google Scholar 

  15. Crouch, J.J., Sakaguchi, N., Lytle, C. & Schulte, B.A. Immunohistochemical localization of the Na-K-Cl co-transporter (NKCC1) in the gerbil inner ear. J. Histochem. 45, 773–778 (1997).

    CAS  Google Scholar 

  16. Goto, S., Oshima, T., Ikeda, K., Ueda, N. & Takasaka, T. Expression and localization of the Na-K-2Cl cotransporter in the rat cochlea. Brain Res. 765, 324–326 (1997).

    Article  CAS  Google Scholar 

  17. Mizuta, K., Adachi, M. & Isawa, K.H. Ultrastructural localization of the Na-K-2Cl cotransporter in the lateral wall of the rabbit cochlear duct. Hearing Res. 106, 154–162 (1997).

    Article  CAS  Google Scholar 

  18. Deol, M.S. Inherited diseases of the inner ear in man in light of studies on the mouse. J. Mol. Genet. 5, 137–158 (1968).

    CAS  Google Scholar 

  19. Belal, A. & Ylikoski, J. Pathologic significance of Meniere's symptom complex: a histopathologic and electron microscopic study. Am. J. Otolaryngol. 1, 275–284 (1980).

    Article  Google Scholar 

  20. Plotkin, M.D. et al. Expression of the Na+-K+-2Cl- cotransporter BSC2 in the nervous system. Am. J. Physiol. 272, C173–C183 (1997).

    Article  CAS  Google Scholar 

  21. Alvarez-Leefmans, F.J., Nani, A. & Marquez, S. in Presynaptic Inhibition and Neural Control (eds Rudomin, P., Romo, R. & Mendell, L.M.) 50–79 (Oxford University Press, New York, 1998).

    Google Scholar 

  22. Wangemann, P., Liu, J. & Marcus, D.C. Ion transport mechanisms responsible for K+ secretion and the transepithelial voltage across marginal cells of stria vascularis in vitro. Hearing Res. 84, 19–29 (1995).

    Article  CAS  Google Scholar 

  23. Rybak, L.P. Ototoxicity of loop diuretics. Otolaryngol. Clin. North Am. 26, 829–844 (1993).

    CAS  PubMed  Google Scholar 

  24. Ikeda, K., Oshima, T., Hidaka, H. & Takasaka, T. Molecular and clinical implications of loop diuretic ototoxicity. Hearing Res. 107, 1–8 (1997).

    Article  CAS  Google Scholar 

  25. Cooperman, L.G. & Rubin, I.L. Toxicity of ethacrynic acid and furosemide. Am. Heart J. 85, 831–834 (1973).

    Article  CAS  Google Scholar 

  26. Rose, B.D. Diuretics. Kidney Int. 39, 336–252 (1991).

    Article  CAS  Google Scholar 

  27. Kalatziz, V. & Petit, C. The fundamental and medical impacts of recent progress in research on hereditary hearing loss. Hum. Mol. Genet. 7, 1589–1597 (1998).

    Article  Google Scholar 

  28. Lynch, E.D. et al. Nonsyndromic deafness DFNA1 associated with mutations of a human homolog of the Drosophila gene diaphanous. Science 278, 1315–1318 (1997).

    Article  CAS  Google Scholar 

  29. Randall, J., Thorne, T. & Delpire, E. Partial cloning and characterization of Slc12a2: the gene encoding the secretory Na+-K+-2Cl- cotransporter. Am. J. Physiol. 273, C1267–C1277 (1997).

    Article  CAS  Google Scholar 

  30. Mountford, P. et al. Dicistronic targeting constructs: reporters and modifiers of mammalian gene expression. Proc. Natl Acad. Sci. USA 91, 4303–4307 (1994).

    Article  CAS  Google Scholar 

Download references


We thank The Vanderbilt Ingram Cancer Center Transgenic/ES Cell Shared Resource Core for expertise and help, and D.B. Mount for helpful discussions. This work was supported by NHLBI and a Vanderbilt University Medical Center intramural grant. E.D. is an Established Investigator from the American Heart Association.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Eric Delpire.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Delpire, E., Lu, J., England, R. et al. Deafness and imbalance associated with inactivation of the secretory Na-K-2Cl co-transporter. Nat Genet 22, 192–195 (1999).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing