Abstract
The role of cytosolic free Ca2+ ([Ca2+](i)) in hypoxic injury was investigated in rat proximal tubules. [Ca2+](i) was measured using fura-2 and cell injury was estimated with propidium iodide (PI) in individual tubules using video imaging fluorescence microscopy. [Ca2+](i) increased from ~ 170 to ~ 390 nM during 5 min of hypoxia. This increase preceded detectable cell injury as assessed by PI and was reversible with reoxygenation. 1,2-Bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA; 100 μM) reduced [Ca2+](i) under basal conditions (~ 80 nM) and during hypoxia (~ 120 nM) and significantly attenuated hypoxic injury. When [Ca2+](i) and hypoxic cell injury were studied concurrently in the same individual tubules, the 10 min [Ca2+](i) rise correlated significantly with subsequent cell damage observed at 20 min. 2 mM glycine did not block the rise in [Ca2+](i), yet protected the tubules from hypoxic injury. These results indicate that in rat proximal tubules, hypoxia induces an increase of [Ca2+](i) which occurs before cell damage. The protective effect of BAPTA supports a role for [Ca2+](i) in the initiation of hypoxic proximal tubule injury. The glycine results, however, implicate calcium-independent mechanisms of injury and/or blockade of calcium-mediated processes of injury such as activation of phospholipases or proteases.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1922-1929 |
| Number of pages | 8 |
| Journal | Journal of Clinical Investigation |
| Volume | 93 |
| Issue number | 5 |
| State | Published - May 1994 |
| Externally published | Yes |
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Keywords
- adenosine triphosphate
- BAPTA
- computer-assisted image processing
- fura-2
- propidium iodide
ASJC Scopus subject areas
- Medicine(all)
Cite this
Evidence for role of cytosolic free calcium in hypoxia-induced proximal tubule injury. / Kribben, Andreas; Wieder, Eric; Wetzels, Jack F M; Yu, Luis; Gengaro, Patricia E.; Burke, Thomas J.; Schrier, Robert W.
In: Journal of Clinical Investigation, Vol. 93, No. 5, 05.1994, p. 1922-1929.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Evidence for role of cytosolic free calcium in hypoxia-induced proximal tubule injury
AU - Kribben, Andreas
AU - Wieder, Eric
AU - Wetzels, Jack F M
AU - Yu, Luis
AU - Gengaro, Patricia E.
AU - Burke, Thomas J.
AU - Schrier, Robert W.
PY - 1994/5
Y1 - 1994/5
N2 - The role of cytosolic free Ca2+ ([Ca2+](i)) in hypoxic injury was investigated in rat proximal tubules. [Ca2+](i) was measured using fura-2 and cell injury was estimated with propidium iodide (PI) in individual tubules using video imaging fluorescence microscopy. [Ca2+](i) increased from ~ 170 to ~ 390 nM during 5 min of hypoxia. This increase preceded detectable cell injury as assessed by PI and was reversible with reoxygenation. 1,2-Bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA; 100 μM) reduced [Ca2+](i) under basal conditions (~ 80 nM) and during hypoxia (~ 120 nM) and significantly attenuated hypoxic injury. When [Ca2+](i) and hypoxic cell injury were studied concurrently in the same individual tubules, the 10 min [Ca2+](i) rise correlated significantly with subsequent cell damage observed at 20 min. 2 mM glycine did not block the rise in [Ca2+](i), yet protected the tubules from hypoxic injury. These results indicate that in rat proximal tubules, hypoxia induces an increase of [Ca2+](i) which occurs before cell damage. The protective effect of BAPTA supports a role for [Ca2+](i) in the initiation of hypoxic proximal tubule injury. The glycine results, however, implicate calcium-independent mechanisms of injury and/or blockade of calcium-mediated processes of injury such as activation of phospholipases or proteases.
AB - The role of cytosolic free Ca2+ ([Ca2+](i)) in hypoxic injury was investigated in rat proximal tubules. [Ca2+](i) was measured using fura-2 and cell injury was estimated with propidium iodide (PI) in individual tubules using video imaging fluorescence microscopy. [Ca2+](i) increased from ~ 170 to ~ 390 nM during 5 min of hypoxia. This increase preceded detectable cell injury as assessed by PI and was reversible with reoxygenation. 1,2-Bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA; 100 μM) reduced [Ca2+](i) under basal conditions (~ 80 nM) and during hypoxia (~ 120 nM) and significantly attenuated hypoxic injury. When [Ca2+](i) and hypoxic cell injury were studied concurrently in the same individual tubules, the 10 min [Ca2+](i) rise correlated significantly with subsequent cell damage observed at 20 min. 2 mM glycine did not block the rise in [Ca2+](i), yet protected the tubules from hypoxic injury. These results indicate that in rat proximal tubules, hypoxia induces an increase of [Ca2+](i) which occurs before cell damage. The protective effect of BAPTA supports a role for [Ca2+](i) in the initiation of hypoxic proximal tubule injury. The glycine results, however, implicate calcium-independent mechanisms of injury and/or blockade of calcium-mediated processes of injury such as activation of phospholipases or proteases.
KW - adenosine triphosphate
KW - BAPTA
KW - computer-assisted image processing
KW - fura-2
KW - propidium iodide
UR - http://www.scopus.com/inward/record.url?scp=0028349244&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0028349244&partnerID=8YFLogxK
M3 - Article
C2 - 8182125
AN - SCOPUS:0028349244
VL - 93
SP - 1922
EP - 1929
JO - Journal of Clinical Investigation
JF - Journal of Clinical Investigation
SN - 0021-9738
IS - 5
ER -