Table 1.

Summary of HIF-1α and -2α expression patternsa

HIF-1αHIF-2α
Carbon MonoxideCobaltous ChlorideTotal IschemiaCarbon MonoxideCobaltous ChlorideTotal Ischemia
a HIF, hypoxia-inducible factor; S1 to S3, proximal tubule segments; TAL, thick ascending limb; DCT, distal convoluted tubule; CNT, connecting tubule; CD, collecting duct; IC, interstitial cells; EC, endothelial cells. The average signal intensity for each cell type within the different zones of the kidney is indicated as follows: −, no staining; +, weak but definite staining; ++, strong staining; +++, very strong staining; r, staining of the respective cell type was observed only rarely and not in every specimen obtained under a certain condition; <10%, overall <10% of glomeruli stained positive.
b Because of inhomogeneous perfusion fixation after renal artery clamping, the overall resolution of tissue morphologic features was lower and identification of tubular structures was less certain; therefore, staining of some tubular segments that overall appeared negative cannot be excluded with certainty.
c Under ischemic conditions, it was not possible to clearly attribute signals in the outer stripe to interstitial or endothelial cells.
Cortex
    glomeruli+ (r)++ (<10%)+ (<10%)+ (<10%)
    S1++ (r)b
    S2+++b
    S3+ (r)b
    TALb
    macula densab
    DCT++b
    CNT+++++++
    CD++++++
    IC+++++
    EC++++
Outer stripe
    S3++ (r)b
    TALb
    CD++++++
    IC++++c
    EC++ (r)+c
Inner stripe
    thin limbs+ (r)+ (r)
    TAL+++
    CD++++++++
    IC+ (r)+++++
    EC+++
Inner medulla
    CD+++ (r)
    IC+++++++
    thin limbs/EC++ (r)+++++
Papilla
    CD++++++
    IC+++++++++
    thin limbs/EC++++++