The lactacid oxygen debt in frogs after one hour's apnoea in air

Aspects of anuran metabolism : effects of chronic hypoxia on maximal oxygen uptake rates and the fate of lactic acid

“…Xenopus laevis is an example of an anuran with both a high Vo 2 ,max and high lactate concentrations during activity (Hillman, 1976;Putnam, 1979b Oxygen availability can be potentially reduced in aquatic environments, during periods of submergence in hypoxic waters, when burrowed or at high altitudes. Some physiological effects of hypoxia on amphibians have been studied, including effects on heart rate and degree of dilation in cutaneous and skeletal muscle capillaries (Armentrout and Rose, 1971), respiratory patterns (Boutilier and Towes, 1977), and metabolic responses such as lactate levels, liver glycogen levels, and blood sugar (Armentrout and Rose, 1971;Jones and Mustafa, 1973). These studies were concerned with the effect of hypoxia on resting oxygen consumption and did not address its effect on maximal rates of oxygen consumption.…”