Abstract
In the ileum of the brushtail possum, Trichosurus vulpecula, fluid secretion appears to be driven by electrogenic HCO3 − secretion. Consistent with this, the cystic fibrosis transmembrane conductance regulator is expressed in the apical membrane of the ileal epithelial cells and the pancreatic or secretory variant of the NaHCO3 cotransporter in the basolateral membrane. This suggests that in the possum ileum, electrogenic HCO3 − secretion is driven by basolateral NaHCO3 cotransporter (NBC) activity. To determine if the NBC contributes to HCO3 − secretion in the possum ileum, intracellular pH (pHi) measurements in isolated villi were used to demonstrate NBC activity in the ileal epithelial cells and investigate the effect of cAMP-dependent secretagogues. In CO2/HCO3 −-free solutions, recovery of the epithelial cells from an acid load was Na+-dependent and ≈80% inhibited by ethyl-isopropyl-amiloride (EIPA, 10 µmol L−1), indicative of the presence of an Na+/H+ exchanger, most likely NHE1. However, in the presence of CO2/HCO3 −, EIPA only inhibited ≈ 50% of the recovery, the remainder was inhibited by 4,4′-diisothiocyano-2,2′-stilbenedisulfonic acid (DIDS, 500 µmol L−1), indicative of NBC activity. Under steady-state conditions, NHE1 inhibition by EIPA had little effect on pHi in the presence or absence of secretagogues, but NBC inhibition with DIDS resulted in a rapid acidification of the cells, which was increased fivefold by secretagogues. These data demonstrate the functional activity of an NaHCO3 cotransporter in the ileal epithelial cells. Furthermore, the stimulation of NBC activity by secretagogues is consistent with the involvement of an NaHCO3 cotransporter in electrogenic HCO3 − secretion.
Similar content being viewed by others
References
Aronson PS, Nee J, Suhm MA (1982) Modifier role of internal H+ in activating the Na+-H+ exchanger in renal microvillus membrane vesicles. Nature 299:161–163
Bachmann O, Rossmann H, Berger UV, Colledge WH, Ratcliff R, Evans MJ, Gregor M, Seidler U (2003) cAMP-mediated regulation of murine intestinal/pancreatic Na+/HCO3 − cotransporter subtype pNBC1. Am J Physiol 284:G37–G45
Bartolo R, Harfoot N, Gill M, Demmers K, McLeod B, Butt AG (2009a) Electrogenic Cl– secretion does not occur in the ileum of the possum Trichosurus vulpecula due to low levels of NKCC1 expression. J Comp Physiolv [B] 179:997–1010
Bartolo R, Harfoot N, Gill M, McLeod B, Butt AG (2009b) Secretagogues stimulate electrogenic HCO3 – secretion in the ileum of the brushtail possum, Trichosurus vulpecula. Evidence for the role of a NaHCO3 cotransporter. J Exp Biol 212:2645–2655
Butt AG, Hamilton KL (1998) Ion channels in isolated mouse jejunal crypts. Pflugers Arch Eur J Physiol 435:528–538
Butt AG, Mathieson SE, McLeod BJ (2002) Electrogenic ion transport in the intestine of the Australian common brushtail possum, Trichosurus vulpecula: indications of novel transport patterns in a marsupial. J Comp Physiolv [B] 172:495–502
Counillon L, Scholz W, Lang HJ, Pouyssegur J (1993) Pharmacological characterization of stably transfected Na+/H+ antiporter isoforms using amiloride analogs and a new inhibitor exhibiting anti-ischemic properties. Mol Pharmacol 44:1041–1045
Culliford S, Ellory C, Lang HJ, Englert H, Staines H, Wilkins R (2003) Specificity of classical and putative Cl– transport inhibitors on membrane transport pathways in human erythrocytes. Cell Physiol Biochem 13:181–188
Damkier HH, Nielsen S, Praetorius J (2007) Molecular expression of SLC4-derived Na+-dependent anion transporters in selected human tissues. Am J Physiol 293:R2136–R2146
Field M (2003) Intestinal ion transport and the pathophysiology of diarrhea. J Clin Invest 111:931–943
Ford P, Rivarola V, Kierbel A, Chara O, Blot-Chabaud M, Farman N, Parisi M, Capurro C (2002) Differential role of Na+/H+ exchange isoforms NHE-1 and NHE-2 in a rat cortical collecting duct cell line. J Membr Biol 190:117–125
Gill M, Bartolo RC, Demmers K, Fan S, Harfoot N, Butt AG (2011) The distribution and expression of CFTR restricts electrogenic anion secretion to the ileum of the brushtail possum, Trichosurus vulpecula. J Exp Biol 214:1943–1954
Grichtchenko II, Choi I, Zhong X, Bray-Ward P, Russell JM, Boron WF (2001) Cloning, characterization, and chromosomal mapping of a human electroneutral Na+-driven Cl–/HCO3 – exchanger. J Biol Chem 276:8358–8363
Grosell M, Genz J, Taylor JR, Perry SF, Gilmour KM (2009a) The involvement of H+-ATPase and carbonic anhydrase in intestinal HCO3 – secretion in seawater-acclimated rainbow trout. J Exp Biol 212:1940–1948
Grosell M, Mager EM, Williams C, Taylor JR (2009b) High rates of HCO3 – secretion and Cl– absorption against adverse gradients in the marine teleost intestine: the involvement of an electrogenic anion exchanger and H+-pump metabolon? J Exp Biol 212:1684–1696
Guffey S, Esbaugh A, Grosell M (2011) Regulation of apical H+-ATPase activity and intestinal HCO3 – secretion in marine fish osmoregulation. Am J Physiol 301:R1682–R1691
Halm DR, Frizzell RA (1990) Intestinal chloride secretion. In: Lebenthal E, Duffey ME (eds) Textbook of secretory diarrhea. Raven Press, New York, pp 47–58
Hoogerwerf WA, Tsao SC, Devuyst O, Levine SA, Yun CHC, Yip JW, Cohen ME, Wilson PD, Lazenby AJ, Tse CM, Donowitz M (1996) NHE2 and NHE3 are human and rabbit intestinal brush-border proteins. Am J Physiol 270:G29–G41
Jacob P, Christiani S, Rossmann H, Lamprecht G, Vieillard-Baron D, Muller R, Gregor M, Seidler U (2000) Role of Na+HCO3 – cotransporter NBC1, Na+/H+ exchanger NHE1, and carbonic anhydrase in rabbit duodenal bicarbonate secretion. Gastroenterology 119:406–419
Ledoussal C, Woo AL, Miller ML, Shull GE (2001) Loss of the NHE2 Na+/H+ exchanger has no apparent effect on diarrheal state of NHE3-deficient mice. Am J Physiol 281:G1385–G1396
Leem CH, LagadicGossmann D, VaughanJones RD (1999) Characterization of intracellular pH regulation in the guinea-pig ventricular myocyte. J Physiol London 517:159–180
Noel J, Pouyssegur J (1995) Hormonal regulation, pharmacology, and membrane sorting of vertebrate Na+/H+ exchanger isoforms. Am J Physiol 268:C283–C296
Novak I, Greger R (1988) Electrophysiological study of transport systems in isolated perfused pancreatic ducts: properties of the basolateral membrane. Pflugers Arch 411:58–68
Odgaard E, Jakobsen JK, Frische S, Praetorius J, Nielsen S, Aalkjaer C, Leipziger J (2004) Basolateral Na+-dependent HCO3 – transporter NBCn1-mediated HCO3 – influx in rat medullary thick ascending limb. J Physiol (Lond) 555:205–218
Paris S, Pouyssegur J (1983) Biochemical characterization of the amiloride-sensitive Na+/H+ antiport in Chinese hamster lung fibroblasts. J Biol Chem 258:3503–3508
Pedersen S, Cala P (2004a) Comparative biology of the ubiquitous Na+/H+ exchanger, NHE1: lessons from erythrocytes. J Exp Zool A Com Exp Biol 301:569–578
Pedersen SF, Cala PM (2004b) Comparative biology of the ubiquitous Na+/H + exchanger, NHE1: lessons from erythrocytes. J Exp Zool A Comp Exp Biol 301:569–578 doi:10.1002/jez.a.47
Praetorius J, Andreasen D, Jensen BL, Ainsworth MA, Friis UG, Johansen T (2000) NHE1, NHE2, and NHE3 contribute to regulation of intracellular pH in murine duodenal epithelial cells. Am J Physiol 278:G197–G206
Praetorius J, Hager H, Nielsen S, Aalkjaer C, Friis UG, Ainsworth MA, Johansen T (2001) Molecular and functional evidence for electrogenic and electroneutral Na+-HCO3 – cotransporters in murine duodenum. Am J Physiol 280:G332–G343
Praetorius J, Nejsum LN, Nielsen S (2004) A SCL4A10 gene product maps selectively to the basolateral plasma membrane of choroid plexus epithelial cells. Am J Physiol 286:C601–C610
Schneider L, Stock CM, Dieterich P, Jensen BH, Pedersen LB, Satir P, Schwab A, Christensen ST, Pedersen SF (2009) The Na+ /H+ exchanger NHE1 is required for directional migration stimulated via PDGFR-alpha in the primary cilium. J Cell Biol 185:163–176
Schultheis PJ, Clarke LL, Meneton P, Miller ML, Soleimani M, Gawenis LR, Riddle TM, Duffy JJ, Doetschman T, Wang T, Giebisch G, Aronson PS, Lorenz JN, Shull GE (1998) Renal and intestinal absorptive defects in mice lacking the NHE3 Na+/H+ exchanger. Nat Genet 19:282–285
Seidler U, Rossmann H, Jacob P, Bachmann O, Christiani S, Lamprecht G, Gregor M (2000) Expression and function of Na+HCO3 – cotransporters in the gastrointestinal tract. In: Schulzke J-D, Fromm M (eds) Epithelial transport and barrier function, vol 915. Annals of the New York Academy of Sciences. Blackwell, Boston, pp 1–14
Singh AK, Xia W, Riederer B, Juric M, Li J, Zheng W, Cinar A, Xiao F, Bachmann O, Song P, Praetorius J, Aalkjaer C, Seidler U (2013) Essential role of the electroneutral Na+ -HCO 3 – cotransporter NBCn1 in murine duodenal acid-base balance and colonic mucus layer build-up in vivo. J Physiol (Lond) 591:2189–2204
Steward M, Ishiguro H, Case RM (2005) Mechanisms of bicarbonate secretion in the pancreatic duct. Annu Rev Physiol 67:377–409
Szabo EZ, Numata M, Shull GE, Orlowski J (2000) Kinetic and pharmacological properties of human brain Na+/H+ exchanger isoform 5 stably expressed in Chinese hamster ovary cells. J Biol Chem 275:6302–6307
Takaichi K, Balkovetz DF, Van Meir E, Warnock DG (1993) Cytosolic pH sensitivity of an expressed human NHE-1 Na+/H+ exchanger. Am J Physiol 264:C944–C950
Taylor JR, Mager EM, Grosell M (2010) Basolateral NBCe1 plays a rate-limiting role in transepithelial intestinal HCO3 – secretion, contributing to marine fish osmoregulation. J Exp Biol 213:459–468
Tse C-M, Brant SR, Walker MS, Pouyssegur J, Donowitz M (1992) Cloning and sequencing of a rabbit cDNA encoding an intestinal and kidney-specific Na+/H+ exchanger isoform (NHE-3). J Biol Chem 267:9340–9346
Tse CM, Levine SA, Yun CH, Brant SR, Pouyssegur J, Montrose MH, Donowitz M (1993a) Functional characteristics of a cloned epithelial Na+/H+ exchanger (NHE3): resistance to amiloride and inhibition by protein kinase C. Proc Natl Acad Sci USA 90:9110–9114
Tse M, Levine S, Yun C, Brant S, Counillon LT, Pouyssegur J, Donowitz M (1993b) Structure/function studies of the epithelial isoforms of the mammalian Na+/H+ exchanger gene family. J Membr Biol 135:93–108
Villanger O, Veel T, Raeder MG (1995) Secretin causes H+/HCO3 – secretion from pig pancreatic ductules by vacuolar-type H+-adenosine triphosphatase. Gastroenterology 108:850–859
Willoughby D, Masada N, Crossthwaite AJ, Ciruela A, Cooper DM (2005) Localized Na+/H+ exchanger 1 expression protects Ca2+-regulated adenylyl cyclases from changes in intracellular pH. J Biol Chem 280:30864–30872
Xia W, Yu Q, Riederer B, Singh AK, Engelhardt R, Yeruva S, Song P, Tian D-A, Soleimani M, Seidler U (2013) The distinct roles of anion transporters Slc26a3 (DRA) and Slc26a6 (PAT-1) in fluid and electrolyte absorption in the murine small intestine. Pflügers Archiv 466:1541–1556
Xiao F, Juric M, Li J, Riederer B, Yeruva S, Kumar Singh A, Zheng L, Glage S, Kollias G, Dudeja P, Tian D-A, Xu G, Zhu J, Bachmann O, Seidler U (2012) Loss of downregulated in adenoma (DRA) impairs mucosal HCO 3 – secretion in murine ileocolonic inflammation. Inflamm Bowel Dis 18:101–111
Yamamoto T, Swietach P, Rossini A, Loh SH, Vaughan-Jones RD, Spitzer KL (2005) Functional diversity of electrogenic Na+-HCO3 – cotransport in ventricular myocytes from rat, rabbit and guinea pig. J Physiol (Lond) 562:455–475
Acknowledgements
This work was supported by a University of Otago Research Grant, and grants from the Foundation for Research Science and Technology, the Animal Health Board Inc., and the National Centre for Possum Biocontrol.
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by I. D. Hume.
Rights and permissions
About this article
Cite this article
Chao, PC., Butt, A.G. cAMP-dependent secretagogues stimulate the NaHCO3 cotransporter in the villous epithelium of the brushtail possum, Trichosurus vulpecula . J Comp Physiol B 187, 1019–1028 (2017). https://doi.org/10.1007/s00360-017-1063-z
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00360-017-1063-z