Abstract
This investigation evaluated the hypothesis that the age-related decline in cold-induced thermogenesis observed in male (F344) rats is associated with altered substrate concentrations of glucose, lactate, and/or liver and muscle glycogen. Body mass-independent O2 consumption, core temperature, and serum glucose and lactate concentrations were measured at rest and during 4 h of exposure to 5°C in male F344 rats ages 6, 12, and 26 months. At the end of the 4-h cold exposure, liver, soleus, and gastrocnemius tissues were removed, frozen, and analyzed for glycogen concentration and/or citrate synthase activity. Core temperature decreased during cold exposure and was consistently less in the 26-month versus the 6- and 12-month rats. There were no significant differences between the 6- and 12-month-old rats with respect to cold-induced O2 consumption, but measures were significantly lower in the 26-month-old rats. During cold exposure, serum lactate and glucose concentrations increased in the 26-month-old animals compared to those in the 6- and 12-month-old rats, while liver glycogen concentrations decreased in all groups, and gastrocnemius glycogen contents decreased in the 12- and 26-month-old rats. Citrate synthase specific activity (μmol · [min · μg · protein]-1) did not differ with age. These data suggest that carbohydrate availability (as measured by serum glucose and muscle glycogen) is not a limiting factor in the attenuated cold-exposed thermogenic response of the 26-month-old male F344 rat. However, it appears that the 26-month-old rat may have a diminished capacity to fully oxidize carbohydrate during cold exposure.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 179-190 |
| Number of pages | 12 |
| Journal | Experimental Gerontology |
| Volume | 27 |
| Issue number | 2 |
| DOIs | |
| State | Published - 1992 |
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Keywords
- aging rats
- cold-induced thermogenesis
- glucose
- lactate
- liver and muscle glycogen
ASJC Scopus subject areas
- Aging
- Medicine(all)
Cite this
Effect of cold on serum substrate and glycogen concentration in young and old fischer 344 rats. / Larkin, Lisa M.; Horwitz, Barbara A; McDonald, Roger B.
In: Experimental Gerontology, Vol. 27, No. 2, 1992, p. 179-190.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effect of cold on serum substrate and glycogen concentration in young and old fischer 344 rats
AU - Larkin, Lisa M.
AU - Horwitz, Barbara A
AU - McDonald, Roger B.
PY - 1992
Y1 - 1992
N2 - This investigation evaluated the hypothesis that the age-related decline in cold-induced thermogenesis observed in male (F344) rats is associated with altered substrate concentrations of glucose, lactate, and/or liver and muscle glycogen. Body mass-independent O2 consumption, core temperature, and serum glucose and lactate concentrations were measured at rest and during 4 h of exposure to 5°C in male F344 rats ages 6, 12, and 26 months. At the end of the 4-h cold exposure, liver, soleus, and gastrocnemius tissues were removed, frozen, and analyzed for glycogen concentration and/or citrate synthase activity. Core temperature decreased during cold exposure and was consistently less in the 26-month versus the 6- and 12-month rats. There were no significant differences between the 6- and 12-month-old rats with respect to cold-induced O2 consumption, but measures were significantly lower in the 26-month-old rats. During cold exposure, serum lactate and glucose concentrations increased in the 26-month-old animals compared to those in the 6- and 12-month-old rats, while liver glycogen concentrations decreased in all groups, and gastrocnemius glycogen contents decreased in the 12- and 26-month-old rats. Citrate synthase specific activity (μmol · [min · μg · protein]-1) did not differ with age. These data suggest that carbohydrate availability (as measured by serum glucose and muscle glycogen) is not a limiting factor in the attenuated cold-exposed thermogenic response of the 26-month-old male F344 rat. However, it appears that the 26-month-old rat may have a diminished capacity to fully oxidize carbohydrate during cold exposure.
AB - This investigation evaluated the hypothesis that the age-related decline in cold-induced thermogenesis observed in male (F344) rats is associated with altered substrate concentrations of glucose, lactate, and/or liver and muscle glycogen. Body mass-independent O2 consumption, core temperature, and serum glucose and lactate concentrations were measured at rest and during 4 h of exposure to 5°C in male F344 rats ages 6, 12, and 26 months. At the end of the 4-h cold exposure, liver, soleus, and gastrocnemius tissues were removed, frozen, and analyzed for glycogen concentration and/or citrate synthase activity. Core temperature decreased during cold exposure and was consistently less in the 26-month versus the 6- and 12-month rats. There were no significant differences between the 6- and 12-month-old rats with respect to cold-induced O2 consumption, but measures were significantly lower in the 26-month-old rats. During cold exposure, serum lactate and glucose concentrations increased in the 26-month-old animals compared to those in the 6- and 12-month-old rats, while liver glycogen concentrations decreased in all groups, and gastrocnemius glycogen contents decreased in the 12- and 26-month-old rats. Citrate synthase specific activity (μmol · [min · μg · protein]-1) did not differ with age. These data suggest that carbohydrate availability (as measured by serum glucose and muscle glycogen) is not a limiting factor in the attenuated cold-exposed thermogenic response of the 26-month-old male F344 rat. However, it appears that the 26-month-old rat may have a diminished capacity to fully oxidize carbohydrate during cold exposure.
KW - aging rats
KW - cold-induced thermogenesis
KW - glucose
KW - lactate
KW - liver and muscle glycogen
UR - http://www.scopus.com/inward/record.url?scp=0026647769&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026647769&partnerID=8YFLogxK
U2 - 10.1016/0531-5565(92)90042-X
DO - 10.1016/0531-5565(92)90042-X
M3 - Article
VL - 27
SP - 179
EP - 190
JO - Experimental Gerontology
JF - Experimental Gerontology
SN - 0531-5565
IS - 2
ER -