Measurement of plasma free fatty acid turnover and oxidation using [1-13C]palmitic acid

This study was undertaken to determine the effects of propylthiouracil-induced thyroid deficiency on a) the capacity of muscle homogenates to oxidize [2-14C]pyruvate and [U-14C]palmitate and b) glycogen depletion during exercise in liver and in fast-oxidative-glycogenolytic (FOG), fast-glycogenolytic (FG), and slow-oxidative (SO) muscle. Relative to the rates for normal rats, oxidation with pyruvate was reduced by 53, 68, and 58%, and palmitate by 40, 50, and 48% in FOG, FG, and SO muscle, respectively (P less than 0.05). Normal rats ran longer than thyroid-deficient rats at 26.7 m/min (87 ± 8 vs. 37 ± 5 min). After 40 min of running (22 m/min), the amount of glycogen consumed in normal FOG, FG, and SO muscle and in liver amounted to only 23, 12, 66, and 52%, respectively, of that for their thyroid-deficient counterparts. Also, normal rats maintained higher plasma free fatty acid levels than thyroid-deficient rats during both rest and exercise (P less than 0.05). These findings suggest that thyroid deficiency causes a reduced potential for FFA utilization in skeletal muscle that enhances its consumption of glycogen, thereby limiting endurance capacity.

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Influence of glucagon and neurohypophysial hormones on plasma free fatty acid levels in the pigeon

Comparative Biochemistry and Physiology Part A Physiology ◽

10.1016/0300-9629(73)90462-3 ◽

1973 ◽

Vol 45 (2) ◽

pp. 541-547 ◽

Cited By ~ 23

Author(s):

T.M. John ◽

J.C. George

Keyword(s):

Fatty Acid ◽

Free Fatty Acid ◽

Plasma Free Fatty Acid ◽

Neurohypophysial Hormones

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Effects of Diphenylhydantoin upon the Plasma Free Fatty Acid Response Induced by Hormones.

Experimental Biology and Medicine ◽

10.3181/00379727-120-30490 ◽

1965 ◽

Vol 120 (1) ◽

pp. 217-220 ◽

Cited By ~ 2

Author(s):

A. C. Chung

Keyword(s):

Fatty Acid ◽

Free Fatty Acid ◽

Plasma Free Fatty Acid

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The Effects of Cold and Prostaglandin E1 on Lipid Mobilization in the Chicken

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y71-046 ◽

1971 ◽

Vol 49 (5) ◽

pp. 394-398 ◽

Cited By ~ 7

Author(s):

W. D. Wagner ◽

R. A. Peterson ◽

R. J. Cenedella

Keyword(s):

Fatty Acid ◽

Free Fatty Acid ◽

Cold Exposure ◽

Prostaglandin E1 ◽

Plasma Free Fatty Acid ◽

Prostaglandin E ◽

Elevated Plasma ◽

Lower Plasma ◽

Lipid Mobilization ◽

Plasma Ffa

Plasma free fatty acid (FFA) levels and the effects of prostaglandin E1 (PGE1) were studied in cold-acclimated and cold-exposed chickens and compared to controls. Chickens cold-acclimated at 4–7 or 8–11 °C for 4 weeks had significantly elevated plasma FFA when compared to the controls at 19–21 °C. Although PGE1 had no effect on the basal level of FFA of controls, a significantly lower plasma FFA was seen after injection of either 10 or 30 μg PGE1/kg in cold-acclimated chickens. Chickens cold-exposed to 2–3 °C for 4 h demonstrated significant elevations of plasma FFA when compared to controls. Only 30 μg PGE1/kg significantly depressed the plasma FFA in the cold-exposed birds. No inhibition of basal FFA release was seen in control animals. From these experiments, it is concluded that chickens mobilize FFA extensively under cold-exposure and that this stimulated lipolysis is inhibited by PGE1.

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