Editing Collecting duct system (section)

====Intercalated cells====
[[File:Alpha Intercalated Cell Cartoon.svg|thumbnail|Image depicting an α intercalated cell]]

Intercalated cells come in α, β, and non-α non-β varieties and participate in [[acid–base homeostasis]].<ref>{{Cite journal|last1=Alper|first1=S. L.|last2=Natale|first2=J.|last3=Gluck|first3=S.|last4=Lodish|first4=H. F.|last5=Brown|first5=D.|date=1989-07-01|title=Subtypes of intercalated cells in rat kidney collecting duct defined by antibodies against erythroid band 3 and renal vacuolar H+-ATPase|journal=Proceedings of the National Academy of Sciences|volume=86|issue=14|pages=5429–5433|doi=10.1073/pnas.86.14.5429|issn=0027-8424|pmc=297636|pmid=2526338|bibcode=1989PNAS...86.5429A|doi-access=free}}</ref><ref>{{Cite journal|last1=Kim|first1=J.|last2=Kim|first2=Y. H.|last3=Cha|first3=J. H.|last4=Tisher|first4=C. C.|last5=Madsen|first5=K. M.|date=January 1999|title=Intercalated cell subtypes in connecting tubule and cortical collecting duct of rat and mouse|journal=Journal of the American Society of Nephrology|volume=10|issue=1|pages=1–12|doi=10.1681/ASN.V1011|issn=1046-6673|pmid=9890303|doi-access=free}}</ref>

{| class="wikitable"
! Type of cell !! Secretes !! Reabsorbs
 |-
 | α-intercalated cells ||  [[acid]] (via an apical [[proton pump|H<sup>+</sup>-ATPase]] and [[hydrogen-potassium exchanger|H<sup>+</sup>/K<sup>+</sup> exchanger]]) in the form of [[hydrogen ion]]s || [[bicarbonate]] (via [[band 3]], a basolateral [[chloride-bicarbonate exchanger|Cl<sup>−</sup>/HCO<sub>3</sub><sup>−</sup> exchanger]])<ref>{{cite book| title= Essentials of Human Physiology| first= Thomas M. |last= Nosek| chapter=Section 7/7ch07/7ch07p17 |chapter-url=http://humanphysiology.tuars.com/program/section7/7ch07/7ch07p17.htm |archive-url=https://web.archive.org/web/20160324124828/http://humanphysiology.tuars.com/program/section7/7ch07/7ch07p17.htm|archive-date=2016-03-24}} – "Intercalated Cells"</ref>
 |-
 | β-intercalated cells  || bicarbonate (via [[pendrin]] a specialised apical [[chloride-bicarbonate exchanger|Cl<sup>−</sup>/HCO<sub>3</sub><sup>−</sup>]])
|| acid (via a basal [[proton pump|H<sup>+</sup>-ATPase]])
|-
|non-α non-β intercalated cells
|[[acid]] (via an apical [[proton pump|H<sup>+</sup>-ATPase]] and [[hydrogen-potassium exchanger|H<sup>+</sup>/K<sup>+</sup> exchanger]]) and [[bicarbonate]] (via [[pendrin]])<ref>{{Cite journal|last1=Kim|first1=Young-Hee|last2=Kwon|first2=Tae-Hwan|last3=Frische|first3=Sebastian|last4=Kim|first4=Jin|last5=Tisher|first5=C. Craig|last6=Madsen|first6=Kirsten M.|last7=Nielsen|first7=Søren|date=2002-10-01|title=Immunocytochemical localization of pendrin in intercalated cell subtypes in rat and mouse kidney|journal=American Journal of Physiology. Renal Physiology|volume=283|issue=4|pages=F744–F754|doi=10.1152/ajprenal.00037.2002|pmid=12217866|issn=1931-857X}}</ref><ref>{{Cite journal|last1=Wall|first1=Susan M.|last2=Hassell|first2=Kathryn A.|last3=Royaux|first3=Ines E.|last4=Green|first4=Eric D.|last5=Chang|first5=Judy Y.|last6=Shipley|first6=Gregory L.|last7=Verlander|first7=Jill W.|date=2003-01-01|title=Localization of pendrin in mouse kidney|journal=American Journal of Physiology. Renal Physiology|volume=284|issue=1|pages=F229–F241|doi=10.1152/ajprenal.00147.2002|pmid=12388426|s2cid=22831140|issn=1931-857X}}</ref>
| -
|}

For their contribution to acid–base homeostasis, the intercalated cells play important roles in the kidney's response to [[acidosis]] and [[alkalosis]]. Damage to the α-intercalated cell's ability to secrete acid can result in [[renal tubular acidosis|distal renal tubular acidosis]] (RTA type I, classical RTA)(reference). The intercalated cell population is also extensively modified in response to chronic lithium treatment, including the addition of a largely uncharacterized cell type which expressed markers for both intercalated and principal cells.<ref>{{Cite journal|last1=Christensen|first1=Birgitte Mønster|last2=Marples|first2=David|last3=Kim|first3=Young-Hee|last4=Wang|first4=Weidong|last5=Frøkiær|first5=Jørgen|last6=Nielsen|first6=Søren|date=2004-04-01|title=Changes in cellular composition of kidney collecting duct cells in rats with lithium-induced NDI|journal=American Journal of Physiology. Cell Physiology|volume=286|issue=4|pages=C952–C964|doi=10.1152/ajpcell.00266.2003|pmid=14613889|s2cid=20227998|issn=0363-6143|url=http://pdfs.semanticscholar.org/1276/ef349695561b2405c6e47079975cbdb898d4.pdf|archive-url=https://web.archive.org/web/20190219000744/http://pdfs.semanticscholar.org/1276/ef349695561b2405c6e47079975cbdb898d4.pdf|url-status=dead|archive-date=2019-02-19}}</ref><ref>{{Cite journal|last1=Himmel|first1=Nathaniel J.|last2=Wang|first2=Yirong|last3=Rodriguez|first3=Daniel A.|last4=Sun|first4=Michael A.|last5=Blount|first5=Mitsi A.|date=2018-04-18|title=Chronic lithium treatment induces novel patterns of pendrin localization and expression|journal=American Journal of Physiology. Renal Physiology|volume=315|issue=2|pages=F313–F322|doi=10.1152/ajprenal.00065.2018|issn=1931-857X|pmc=6139525|pmid=29667915}}</ref>