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Compensatory elevation of voluntary activity in mouse mutants with impaired mitochondrial energy metabolism.

Lapointe J, G Hughes B, Bigras E, Hekimi S - Physiol Rep (2014)

Bottom Line: We find that both Mclk1(+/-) and RISP(+/P224S) males are capable of restoring their defective metabolic rates by making significantly more voluntary use of a running wheel compared to wild type.However, this increase in voluntary activity does not reflect their exercise capacity, which we found to be impaired as revealed by a shorter treadmill distance run before exhaustion.In contrast to what is observed in Mclk1(+/-) and RISP(+/P224S) mutants, Sod2(+/-) mice with elevated oxidative stress and major mitochondrial dysfunction did not increase voluntary activity.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, McGill University, Montréal, Quebec, Canada Agriculture and Agri-Food Canada, 2000 College St., Sherbrooke, J1M 0C8, Quebec, Canada.

No MeSH data available.


Related in: MedlinePlus

Increased voluntary running wheel activity and metabolic rate inMclk1+/− males. Total number of wheel turnsaccomplished by 3‐month‐old Mclk1+/+and Mclk1+/− mice (n =10–12) during a 60 h period with a 12 h light and 12 h dark cycle. (A). Bars represent means± SEM and a value of P < 0.05 was considered significant. Voluntaryactivity on running wheels was continuously recorded throughout the 60 h period (B). Metabolic rateparameters were also assessed by indirect calorimetry. The shaded areas demarcate the dark phases(from 7:00 pm to 7:00 am). Time “0” is 7:00 am. Changes in oxygen consumption rate(C), respiratory exchange ratio (D) and heat production (E) and were reported. All points representmeans ± SEM over 2 h intervals. A value of P < 0.05 for the genotypeeffect was considered significant.
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fig02: Increased voluntary running wheel activity and metabolic rate inMclk1+/− males. Total number of wheel turnsaccomplished by 3‐month‐old Mclk1+/+and Mclk1+/− mice (n =10–12) during a 60 h period with a 12 h light and 12 h dark cycle. (A). Bars represent means± SEM and a value of P < 0.05 was considered significant. Voluntaryactivity on running wheels was continuously recorded throughout the 60 h period (B). Metabolic rateparameters were also assessed by indirect calorimetry. The shaded areas demarcate the dark phases(from 7:00 pm to 7:00 am). Time “0” is 7:00 am. Changes in oxygen consumption rate(C), respiratory exchange ratio (D) and heat production (E) and were reported. All points representmeans ± SEM over 2 h intervals. A value of P < 0.05 for the genotypeeffect was considered significant.

Mentions: We tested the effects of impaired metabolism on spontaneous activity and vice versa by givinganimals 24‐h access to a running wheel (Figs. 2,3). After a period of adaptation, the total number of wheelturns was calculated for the subsequent 60 h (with 12 h dark/light intervals). As expected,mice of all groups were much more active on the running wheels during the dark periods (Figs. 2B, 3B). However, thetotal number of wheel turns produced throughout the 60 h was much higher than wild‐typecontrols for Mclk1+/− mutants of both sexes (Figs.2A, 3A). A threefoldstatistically significant increase in voluntary activity was observed for the heterozygotes. Thisincrease was clearly seen throughout the experimental period for the males but, for unknown reasons,was observed only in the first and last dark periods for the females (Figs. 2B, 3B). The presence of running wheelsin the metabolic cages rescued the decreased VO2 and heat production observed withoutrunning wheels in Mclk1+/− males (Fig. 2C and E; compare to Fig. 1A and C). In addition, the respiratory exchange ratio was found to be significantly lowerin Mclk1+/− males (Fig. 2D). Metabolic rates were not further increased forMclk1+/− females in presence of running wheels(Fig. 3C–E; compare to Fig. 1).


Compensatory elevation of voluntary activity in mouse mutants with impaired mitochondrial energy metabolism.

Lapointe J, G Hughes B, Bigras E, Hekimi S - Physiol Rep (2014)

Increased voluntary running wheel activity and metabolic rate inMclk1+/− males. Total number of wheel turnsaccomplished by 3‐month‐old Mclk1+/+and Mclk1+/− mice (n =10–12) during a 60 h period with a 12 h light and 12 h dark cycle. (A). Bars represent means± SEM and a value of P < 0.05 was considered significant. Voluntaryactivity on running wheels was continuously recorded throughout the 60 h period (B). Metabolic rateparameters were also assessed by indirect calorimetry. The shaded areas demarcate the dark phases(from 7:00 pm to 7:00 am). Time “0” is 7:00 am. Changes in oxygen consumption rate(C), respiratory exchange ratio (D) and heat production (E) and were reported. All points representmeans ± SEM over 2 h intervals. A value of P < 0.05 for the genotypeeffect was considered significant.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4255820&req=5

fig02: Increased voluntary running wheel activity and metabolic rate inMclk1+/− males. Total number of wheel turnsaccomplished by 3‐month‐old Mclk1+/+and Mclk1+/− mice (n =10–12) during a 60 h period with a 12 h light and 12 h dark cycle. (A). Bars represent means± SEM and a value of P < 0.05 was considered significant. Voluntaryactivity on running wheels was continuously recorded throughout the 60 h period (B). Metabolic rateparameters were also assessed by indirect calorimetry. The shaded areas demarcate the dark phases(from 7:00 pm to 7:00 am). Time “0” is 7:00 am. Changes in oxygen consumption rate(C), respiratory exchange ratio (D) and heat production (E) and were reported. All points representmeans ± SEM over 2 h intervals. A value of P < 0.05 for the genotypeeffect was considered significant.
Mentions: We tested the effects of impaired metabolism on spontaneous activity and vice versa by givinganimals 24‐h access to a running wheel (Figs. 2,3). After a period of adaptation, the total number of wheelturns was calculated for the subsequent 60 h (with 12 h dark/light intervals). As expected,mice of all groups were much more active on the running wheels during the dark periods (Figs. 2B, 3B). However, thetotal number of wheel turns produced throughout the 60 h was much higher than wild‐typecontrols for Mclk1+/− mutants of both sexes (Figs.2A, 3A). A threefoldstatistically significant increase in voluntary activity was observed for the heterozygotes. Thisincrease was clearly seen throughout the experimental period for the males but, for unknown reasons,was observed only in the first and last dark periods for the females (Figs. 2B, 3B). The presence of running wheelsin the metabolic cages rescued the decreased VO2 and heat production observed withoutrunning wheels in Mclk1+/− males (Fig. 2C and E; compare to Fig. 1A and C). In addition, the respiratory exchange ratio was found to be significantly lowerin Mclk1+/− males (Fig. 2D). Metabolic rates were not further increased forMclk1+/− females in presence of running wheels(Fig. 3C–E; compare to Fig. 1).

Bottom Line: We find that both Mclk1(+/-) and RISP(+/P224S) males are capable of restoring their defective metabolic rates by making significantly more voluntary use of a running wheel compared to wild type.However, this increase in voluntary activity does not reflect their exercise capacity, which we found to be impaired as revealed by a shorter treadmill distance run before exhaustion.In contrast to what is observed in Mclk1(+/-) and RISP(+/P224S) mutants, Sod2(+/-) mice with elevated oxidative stress and major mitochondrial dysfunction did not increase voluntary activity.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, McGill University, Montréal, Quebec, Canada Agriculture and Agri-Food Canada, 2000 College St., Sherbrooke, J1M 0C8, Quebec, Canada.

No MeSH data available.


Related in: MedlinePlus