Table 1.

Glycolytic enzyme specific activities (i.u. mg−1 protein) in tissues of Fundulus grandis held under normal and reduced oxygen levels for 4 weeks at 27°C

Muscle Liver Heart Brain
EnzymeNormoxiaHypoxiaNormoxiaHypoxiaNormoxiaHypoxiaNormoxiaHypoxia
HKn.d.n.d.0.003±0.0010.002±0.0020.11±0.020.14±0.02**0.11±0.020.13±0.02**
PGI2.00±0.391.47±0.43**0.59±0.140.71±0.16*2.20±0.342.24±0.381.31±0.161.38±0.17
PFK0.20±0.070.15±0.08*0.008±0.0030.013±0.003**0.15±0.070.13±0.070.11±0.010.11±0.02
ALD1.82±0.321.12±0.36**0.13±0.030.11±0.040.27±0.060.27±0.070.28±0.030.29±0.03
TPI39.5±11.531.8±12.7*15.4±4.916.6±5.513.9±2.516.4±2.8*7.95±1.59.12±1.6*
GAPDH2.47±1.281.64±1.421.30±0.301.68±0.33**1.79±0.601.78±0.671.54±0.181.61±0.20
PGK1.88±0.881.73±0.980.92±0.261.61±0.28**1.46±0.241.54±0.271.11±0.141.22±0.16*
PGM4.12±0.623.44±0.69*0.63±0.120.68±0.131.78±0.351.98±0.391.16±0.181.03±0.20*
ENO0.83±0.510.37±0.56*0.45±0.120.46±0.130.25±0.060.23±0.060.36±0.040.37±0.04
PYK2.11±0.371.63±0.41**0.14±0.030.15±0.040.98±0.221.22±0.24*1.48±0.191.49±0.21
LDH6.91±1.324.84±1.47**2.63±0.663.42±0.73**4.15±0.844.38±0.932.65±0.352.85±0.39
  • HK, hexokinase; PGI, phosphoglucoisomerase; PFK, phosphofructokinase; ALD, aldolase; TPI, triose phosphate isomerase; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; PGK, phosphoglycerokinase; PGM, phosphoglyceromutase; ENO, enolase; PYK, pyruvate kinase; LDH, lactate dehydrogenase.

    Values are least-squared means (±1 s.d.) from two-way ANOVA testing the effects of dissolved oxygen (DO) treatment and sex of fish. Sample sizes were 19 for normoxia and 22 for hypoxia. n.d., not determined.

    Significantly different between normoxia and hypoxia, *P≤0.05; **P≤0.001.