Angiotensin II increases the intracellular calcium activity in podocytes of the intact glomerulus

Kidney Int. 2000 Jan;57(1):41-9. doi: 10.1046/j.1523-1755.2000.00810.x.


Angiotensin II increases the intracellular calcium activity in podocytes of the intact glomerulus.

Background: Knowledge about biological functions of podocytes in the glomerulus is limited because of its unique anatomical location. Here we introduce a new method for measuring the intracellular calcium activity ([Ca2+]i) in the podocyte in the intact glomerulus.

Methods: With the help of fluorescence high-resolution digital imaging and a recently developed ultraviolet laser-scanning microscope, [Ca2+]i was measured in fura-2-loaded glomeruli and single podocytes of intact microdissected rat glomeruli.

Results: Angiotensin II (Ang II) increased [Ca2+]i reversibly in a biphasic and concentration-dependent manner. In contrast to Ang II, bradykinin, thrombin, arginine vasopressin, and serotonin did not change [Ca2+]i in the glomerulus. At reduced extracellular Ca2+ activity, Ang II released [Ca2+]i from intracellular stores, but the second phase, corresponding to a Ca2+ influx from the extracellular space, was absent. The L-type Ca2+ channel blocker nicardipine did not influence the Ang II-mediated [Ca2+]i increase, and an increase of the extracellular K+ concentration did not change [Ca2+]i in the glomerulus. The angrotensin II type I (AT1) receptor antagonist losartan inhibited the Ang II-mediated [Ca2+]i increase. Confocal [Ca2+]i measurements using fura-2 or fluo-3 or fluo-4 on the single cell level show that some of the Ang II-mediated [Ca2+]i response originated from podocytes. Costaining with calcein allowed the identification of podocytes because of the characteristic morphology and location in relationship to the capillary network.

Conclusions: These data suggest that podocytes in the intact glomerulus respond to Ang II with an increase of [Ca2+]i via an AT1 receptor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiotensin II / pharmacology*
  • Animals
  • Arginine Vasopressin / pharmacology
  • Bradykinin / pharmacology
  • Calcium / metabolism*
  • Fluorescent Dyes
  • Kidney Glomerulus / cytology
  • Kidney Glomerulus / drug effects*
  • Kidney Glomerulus / metabolism
  • Microscopy, Confocal
  • Microscopy, Fluorescence
  • Rats
  • Serotonin / pharmacology
  • Thrombin / pharmacology


  • Fluorescent Dyes
  • Angiotensin II
  • Arginine Vasopressin
  • Serotonin
  • Thrombin
  • Bradykinin
  • Calcium