Extracellular ATP increases intracellular calcium in rat terminal collecting duct via a nucleotide receptor

Am J Physiol. 1994 Dec;267(6 Pt 2):F998-1006. doi: 10.1152/ajprenal.1994.267.6.F998.


Recent studies in a variety of cell types have revealed several receptor subtypes that bind ATP and trigger increases in intracellular Ca2+ concentration ([Ca2+]i). The present studies were aimed at determining whether similar receptors are present in the rat terminal inner medullary collecting duct (IMCD). [Ca2+]i was measured using fura 2 in tubules dissected from collagenase-treated rat kidneys. ATP (1-100 microM) caused a rapid increase in [Ca2+]i with a prolonged late phase after an initial peak. A similar rise was observed in tubules exposed to UTP or to the poorly hydrolyzable analogue, adenosine 5'-O-(3-thiotriphosphate) (ATP gamma S). In contrast, agonists that bind P2x, P2y, P2z, and P2t purinergic receptors did not affect [Ca2+]i. Removal of extracellular Ca2+ inhibited the response to ATP by approximately 50% with obliteration of the late phase. Furthermore, indomethacin attenuated the rise in [Ca2+]i produced by ATP. Adenosine analogues also increased [Ca2]i apparently by binding to distinct adenosine receptors rather than to the ATP receptor. We conclude that there is a nucleotide receptor in the rat terminal IMCD, which, when occupied, mobilizes intracellular Ca2+.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine / analogs & derivatives
  • Adenosine / pharmacology
  • Adenosine Triphosphate / analogs & derivatives
  • Adenosine Triphosphate / metabolism
  • Adenosine Triphosphate / pharmacology*
  • Adenosine-5'-(N-ethylcarboxamide)
  • Animals
  • Calcium / metabolism*
  • Collagenases
  • Dinoprostone / biosynthesis
  • Extracellular Space / metabolism*
  • Fura-2
  • Indomethacin / pharmacology
  • Kidney Medulla / metabolism
  • Kidney Tubules, Collecting / metabolism*
  • Male
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Purinergic / metabolism*
  • Receptors, Purinergic P1 / metabolism
  • Receptors, Purinergic P2 / metabolism
  • Uridine Triphosphate / pharmacology


  • Receptors, Purinergic
  • Receptors, Purinergic P1
  • Receptors, Purinergic P2
  • adenosine 5'-O-(3-thiotriphosphate)
  • Adenosine-5'-(N-ethylcarboxamide)
  • Adenosine Triphosphate
  • Collagenases
  • Adenosine
  • Dinoprostone
  • Calcium
  • Fura-2
  • Uridine Triphosphate
  • Indomethacin