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REGULAR OSCILLATIONS IN PODOCYTE CALCIUM IN VIVO
Author(s) -
Burford James,
PetiPeterdi Janos
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.665.26
Subject(s) - podocyte , chemistry , afferent arterioles , tubuloglomerular feedback , calcium , medicine , endocrinology , kidney , renal function , microbiology and biotechnology , biophysics , biology , angiotensin ii , biochemistry , receptor , proteinuria , organic chemistry
Mutations in calcium channels (including TRPC6) highlight the role of podocyte cytosolic calcium (Ca2+) in the regulation of glomerular filtration rate, development of albuminuria and glomerulosclerosis. However, due to technical constraints, the physiological dynamics and role of podocyte (Ca2+) is incompletely understood. We aimed to directly visualize podocyte (Ca2+) in the intact kidney and study its temporal correlations with changes in cell shape and glomerular capillary diameter. Munich‐Wistar‐Fromter rats (n=3) were anesthetized and surgically prepared for renal micropuncture and microperfusion delivery of the calcium fluorophore Rhod‐2AM (10 μM) directly into the Bowman's space for 15 min. Subsequently, intravital multiphoton fluorescence microscopy of podocyte (Ca2+) and glomerular hemodynamics (using 500kDa dextran‐FITC‐labeled plasma) was performed. Podocytes and parietal cells showed propagating two‐component regular (Ca2+) oscillations with a faster (0.12 Hz, cycle time about 10 seconds) and a slower (0.023 Hz, cycle time about 45 seconds) frequencies, suggesting that podocyte (Ca2+) is controlled by the afferent arteriole myogenic and tubuloglomerular feedback (TGF) mechanisms. Propagation of the myogenic and TGF calcium waves suggests that podocytes may be functionally part of the JGA and by actively contracting capillaries they are involved in the control of GFR.