Reassessment of Aerobic Metabolism in Amphibians During Activity
Activity oxygen consumption rates (VO2 max) were determined for a variety of amphibians using both electrical and manual stimulation to elicit and maintain activity. The suitability of manometric measurement of VO2 max was also evaluated.
VO2 max (units, ml/g·h) for three minute activity periods induced by manual stimulation were: Hylaregilla, 1.06±0.10; Hyla cadaverina, 1.25±0.14; Batrachoseps attenuatus, 0.82±0.08; Ensatina eschscholtzi, 0.37±0.6; and Aneides lugubris, 0.70±0.25. VO2 max was 4 to 6 times greater than previously reported values. In all species, VO2 during activity was greater than VO2 during recovery (Tables 1, 2).
VO2 in burst activity (3 min) is about 20% greater than VO2 in sustained activity (30 min) in Rana pipiens (Fig. 1). VO2 max was 3 times greater than previously reported values.
Electrical stimulation can lead to physiological impairment of aerobic metabolism as evidenced by a decline in VO2 with increasing stimulus duration and frequency (Table 1). Electrical stimulation can also lead to errors in VO2 as a result of electrolytic gas generation (Fig. 2).
Manometric measurement of VO2 can seriously underestimate actual oxygen consumption rates because of temperature transients, resulting from both biological and electrical heat production (Fig. 2). Temperature transients also lead to an apparent delayed development of VO2 after the activity about.
Hillman, S. S.,
Shoemaker, V. H.,
Putnam, R. W.,
& Withers, P. C.
(1979). Reassessment of Aerobic Metabolism in Amphibians During Activity. Journal of Comparative Physiology, 129 (4), 309-313.