Table 1.

ATP, ADP, total adenylates (Adtot), phosphocreatine (PCr), creatine (Cr), total creatine (Crtot), sum of high-energy phosphates (HEPtot=ATP+0.5×ADP+PCr), phosphorylation potential (PCr/Cr2) and lactate in cardiac tissue from turtle and trout under oxygenation and after 40 and 70 min of severe hypoxia

O2/N2Rest/stim.ATP (μmol l-1 g-1)ADP (μmol l-1 g-1)PCr (μmol l-1 g-1)CrAdtot (μmol l-1 g-1)Crtot (μmol l-1 g-1)HEPtot (μmol l-1 g-1)PCr/Cr2 (μmol l-1 g-1)Muscle lactate (μmol l-1 g-1)
Turtle
   OxygenatedRest2.51±0.320.51±0.02 4.83±0.31 a 3.31±0.26a3.18±0.34 8.14±0.52 7.60±0.60 a 0.47±0.06a 1.15±0.21 a
   Hypoxia 40 minRest2.35±0.28 0.55±0.03 3.51±0.33b 4.39±0.38 a,b,c 3.04±0.30 7.90±0.63 6.14±0.59a,b 0.19±0.02 b 5.40±1.17b
   Hypoxia 70 minRest1.88±0.27 0.50±0.03 3.38±0.69b 4.04±0.45 a,b 2.50±0.317.42±1.135.51±0.96b,c 0.20±0.01 b 3.48±0.31 b,c
   OxygenatedStim.2.39±0.260.53±0.07 3.96±0.35 b 3.73±0.29a3.08±0.34 7.68±0.58 6.62±0.58 a,b 0.30±0.04c 3.29±0.34 a,c
   Hypoxia 40 minStim.1.74±0.14 0.52±0.04 1.78±0.21c 5.17±0.38 b,c 2.37±0.176.96±0.48 3.78±0.21 c 0.07±0.02 d 11.31±0.62 d
   Hypoxia 70 minStim.1.65±0.16 0.52±0.02 2.93±0.98d 5.40±0.71 c 2.28±0.178.33±1.544.84±1.03b,c 0.10±0.02 b,d 12.85±1.00d
Trout
   OxygenatedRest2.56±0.21a0.59±0.05a 7.97±0.87 a 4.04±0.49a3.38±0.27a 12.0±1.01 a,c 10.83±1.04 a 0.70±0.15a 5.08±0.70 a
   Hypoxia 40 minRest2.21±0.21a 0.98±0.07 b 2.60±0.48b 7.71±0.49 b 3.47±0.26a 10.3±0.86 a,b,c 5.31±0.70b,c 0.04±0.01 b 8.83±1.06b
   Hypoxia 70 minRest2.38±0.29a 0.84±0.09 b,c 3.00±0.39b 7.42±0.76 b 3.46±0.39a10.42±0.97a,b,c5.81±0.67b 0.06±0.01 b 6.91±1.06 a,b
   OxygenatedStim.2.63±0.14a0.68±0.04a,c 8.10±0.61 a 4.82±0.41a3.55±0.17a 12.9±0.80 a 11.06±0.74 a 0.42±0.07c 6.67±0.64 a,b
   Hypoxia 40 minStim.1.30±0.24b 0.76±0.06 c 0.96±0.18b 7.59±0.49 b 2.32±0.31b8.54±0.61b 2.64±0.44 c 0.02±0.003 b 16.52±1.33 c
   Hypoxia 70 minStim.1.46±0.21b 0.79±0.04 c 0.91±0.16b 8.69±0.49 b 2.56±0.22b9.60±0.47c2.77±0.36c 0.01±0.003 b 15.62±3.13c
  • Values are means ± s.e.m. (N=6 for all groups except oxygenated trout preparations for which N=11/12). Dissimilar letters indicate significant differences due to treatments for turtle and trout, respectively, and differences between turtle and trout are indicated by presenting the values in bold.