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Fig. 2. Free ATP and lactate levels of wild-type and mutant chondrocytes cultured
under normoxia and 22 hours hypoxia. (A) Bars representing means ±
standard deviations of free ATP-levels measured in three independent
experiments, normalized to protein content. Free ATP levels were determined in
mutant and wild-type cultures under normoxia and hypoxia. (B) Lactate levels
in supernatants of wild-type chondrocytes cultured at 0.5% oxygen were
significantly increased compared with normoxic levels. Reduced lactate
concentrations were detected in supernatants of HIF-1
-null chondrocytes
under normoxia and hypoxia. Bars are representing the means ± standard
deviations of measured triplicates from three independent experiments,
normalized to protein concentrations. Statistical differences were calculated
as: wild-type normoxia vs HIF-1
-null normoxia; wild-type hypoxia vs
HIF-1
-null hypoxia; wild-type normoxia vs wild-type hypoxia.
*P
0.05; **P
0.01.