Abstract
Oxygen consumption, CO2 excretion, and nitrogenous waste excretion (75% ammonia-N and 25% urea-N) were measured daily in 4-g rainbow trout over a 15-day starvation period. Oxygen consumption and CO2 excretion declined while N excretion increased transiently in the mid-part of the starvation period but was unchanged from control levels at the end. Component losses (as percentage of total fuel used) of protein, lipid, and carbohydrate were 66.5, 31.1, and 2.4% respectively, as measured from changes in body weight and body composition, the latter relative to a control group at day 0. Instantaneous fuel use, as calculated from the respiratory quotients and nitrogen quotients, indicated that relative protein use rose during starvation, but contributed at most 24% of the aerobic fuel (as carbon). Lipid metabolism fell from about 68 to 37%, and was largely replaced by carbohydrate metabolism which rose from 20 to 37%. We conclude that the two approaches measure different processes, and that the instantaneous method is preferred for physiological studies. The compositional method is influence by greater error, and measures the fuels depleted, not necessarily burned, because of possible interconversion and excretion of fuels.
| Original language | English |
|---|---|
| Pages (from-to) | 542-551 |
| Number of pages | 10 |
| Journal | Journal of Comparative Physiology B |
| Volume | 165 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jan 1 1996 |
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Keywords
- Fuel
- Nitrogen quotient
- Rainbow trout, Oncorhynchus
- Respiratory quotient
- Starvation
ASJC Scopus subject areas
- Physiology (medical)
- Environmental Science(all)
- Physiology
- Animal Science and Zoology
Cite this
Respiratory gas exchange, nitrogenous waste excretion, and fuel usage during starvation in juvenile rainbow trout, Oncorhynchus mykiss. / Lauff, R. F.; Wood, C. M.
In: Journal of Comparative Physiology B, Vol. 165, No. 7, 01.01.1996, p. 542-551.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Respiratory gas exchange, nitrogenous waste excretion, and fuel usage during starvation in juvenile rainbow trout, Oncorhynchus mykiss
AU - Lauff, R. F.
AU - Wood, C. M.
PY - 1996/1/1
Y1 - 1996/1/1
N2 - Oxygen consumption, CO2 excretion, and nitrogenous waste excretion (75% ammonia-N and 25% urea-N) were measured daily in 4-g rainbow trout over a 15-day starvation period. Oxygen consumption and CO2 excretion declined while N excretion increased transiently in the mid-part of the starvation period but was unchanged from control levels at the end. Component losses (as percentage of total fuel used) of protein, lipid, and carbohydrate were 66.5, 31.1, and 2.4% respectively, as measured from changes in body weight and body composition, the latter relative to a control group at day 0. Instantaneous fuel use, as calculated from the respiratory quotients and nitrogen quotients, indicated that relative protein use rose during starvation, but contributed at most 24% of the aerobic fuel (as carbon). Lipid metabolism fell from about 68 to 37%, and was largely replaced by carbohydrate metabolism which rose from 20 to 37%. We conclude that the two approaches measure different processes, and that the instantaneous method is preferred for physiological studies. The compositional method is influence by greater error, and measures the fuels depleted, not necessarily burned, because of possible interconversion and excretion of fuels.
AB - Oxygen consumption, CO2 excretion, and nitrogenous waste excretion (75% ammonia-N and 25% urea-N) were measured daily in 4-g rainbow trout over a 15-day starvation period. Oxygen consumption and CO2 excretion declined while N excretion increased transiently in the mid-part of the starvation period but was unchanged from control levels at the end. Component losses (as percentage of total fuel used) of protein, lipid, and carbohydrate were 66.5, 31.1, and 2.4% respectively, as measured from changes in body weight and body composition, the latter relative to a control group at day 0. Instantaneous fuel use, as calculated from the respiratory quotients and nitrogen quotients, indicated that relative protein use rose during starvation, but contributed at most 24% of the aerobic fuel (as carbon). Lipid metabolism fell from about 68 to 37%, and was largely replaced by carbohydrate metabolism which rose from 20 to 37%. We conclude that the two approaches measure different processes, and that the instantaneous method is preferred for physiological studies. The compositional method is influence by greater error, and measures the fuels depleted, not necessarily burned, because of possible interconversion and excretion of fuels.
KW - Fuel
KW - Nitrogen quotient
KW - Rainbow trout, Oncorhynchus
KW - Respiratory quotient
KW - Starvation
UR - http://www.scopus.com/inward/record.url?scp=0029685183&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0029685183&partnerID=8YFLogxK
U2 - 10.1007/BF00387515
DO - 10.1007/BF00387515
M3 - Article
C2 - 8617891
AN - SCOPUS:0029685183
VL - 165
SP - 542
EP - 551
JO - Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology
JF - Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology
SN - 0174-1578
IS - 7
ER -