Turnover rates of mitochondrial respiratory chain enzymes in flying honeybees (Apis mellifera)
✍ Scribed by Suarez, R.K.; Staples, J.F.; Lighton, J.R.B.
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 81 KB
- Volume
- 284
- Category
- Article
- ISSN
- 0022-104X
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✦ Synopsis
Metabolic rates (VCO 2 ) of 32 worker honeybees were determined during agitated flight in a flow-through respirometry chamber. Because honeybees oxidize carbohydrate during flight and display respiratory exchange ratios equal to 1.0, these measured VCO 2 values equal VO 2 . The latter were used to estimate mitochondrial electron transport rates per unit thorax mass during flight. Dual wavelength spectroscopy was used to estimate cytochrome content per unit thorax mass in each individual used for respirometry. Electron flux rate divided by cytochrome content yielded cytochrome turnover rate for each individual. Honeybees possess high cytochrome content and display higher rates of cytochrome turnover during flight than mammalian cardiac and skeletal muscles during maximum aerobic work. The significance of this finding is discussed in relation to the control of respiration and the factors that may set the upper limits to aerobic capacities in muscles.