Palmitic acid uptake by the rat soleus muscle in vitro

Górecka, Monika; Synak, M.; Budohoski, L; Langfort, Józef; Moskalewski, Stanisław; Zernicka, E

doi:10.1139/o01-028

Cited by 5 publications

(2 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, Fürnsinn et al (2000) incubated soleus muscle strips in [U-14 C]-palmitate for 60 min prior to extraction for analyses. Furthermore, Górecka et al (2001) used male Wistar rat soleus muscle strips incubated in [1-…”

Section: Discussionmentioning

confidence: 99%

Oleic acid uptake by in vitro English sparrow skeletal muscle

Sweazea

Braun

2006

J. Exp. Zool.

View full text Add to dashboard Cite

Studies of prolonged avian flight have shown it to require large amounts of energy supplied mainly by free fatty acids (FFA). In the present study, the high levels of plasma ketone bodies found in sparrows (2.58 mmol l(-1)) are supportive of the use of fatty acids for flight. To determine the nature of fatty acid (oleic acid, OA) uptake, various pharmacological agents were used. The uptake of OA was examined using the extensor digitorum communis (EDC) muscle of English sparrows incubated in vitro. Initial studies demonstrated that radiolabeled OA uptake decreased in the presence of increasing unlabeled OA, suggesting that uptake occurred by a facilitative transport process. To further characterize OA uptake, EDC muscles were incubated with either: insulin (2 ng ml(-1)), insulin-like growth factor isoform-1 (IGF-I; 48 ng ml(-1)), 5'-Aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR; 2 mmol) or caffeine (5 mmol). Insulin, but not IGF-I, significantly increased OA uptake by avian EDC (P < 0.01). Caffeine and AICAR were ineffective at increasing OA uptake. A specific inhibitor of FFA transport by fatty acid transporters (FAT/CD36), sulfo-N-succinimidyl oleate (SSO; 500 micromoles), significantly decreased OA uptake at 2.5 min. The effectiveness of SSO suggests that a FAT/CD36-like protein is expressed in avian tissues. As uptake of OA was not completely blocked by SSO, it is likely that other mechanisms for FFA movement across membranes, such as diffusion, may be present.

show abstract

Section: Discussionmentioning

confidence: 99%

Oleic acid uptake by in vitro English sparrow skeletal muscle

Sweazea

Braun

2006

J. Exp. Zool.

View full text Add to dashboard Cite

show abstract

“…on the cell type. In addition, the size of the proteinmediated component is also determined by experimental conditions such as the concentration of FFA that is not bound to BSA (3,22,28). Rather than establishing a precise percentage, it may be more important to know that there is, in fact, a protein-mediated component.…”

Section: Discussionmentioning

confidence: 99%

Thiazolidinediones upregulate impaired fatty acid uptake in skeletal muscle of type 2 diabetic subjects

Wilmsen

Ciaraldi

Carter

et al. 2003

American Journal of Physiology-Endocrinology and Metabolism

View full text Add to dashboard Cite

We examined the regulation of free fatty acid (FFA, palmitate) uptake into skeletal muscle cells of nondiabetic and type 2 diabetic subjects. Palmitate uptake included a protein-mediated component that was inhibited by phloretin. The protein-mediated component of uptake in muscle cells from type 2 diabetic subjects (78 ± 13 nmol · mg protein-1 · min-1) was reduced compared with that in nondiabetic muscle (150 ± 17, P < 0.01). Acute insulin exposure caused a modest (16 ± 5%, P < 0.025) but significant increase in protein-mediated uptake in nondiabetic muscle. There was no significant insulin effect in diabetic muscle (+19 ± 19%, P = not significant). Chronic (4 day) treatment with a series of thiazolidinediones, troglitazone (Tgz), rosiglitazone (Rgz), and pioglitazone (Pio) increased FFA uptake. Only the phloretin-inhibitable component was increased by treatment, which normalized this activity in diabetic muscle cells. Under the same conditions, FFA oxidation was also increased by thiazolidinedione treatment. Increases in FFA uptake and oxidation were associated with upregulation of fatty acid translocase (FAT/CD36) expression. FAT/CD36 protein was increased by Tgz (90 ± 22% over control), Rgz (146 ± 42%), and Pio (111 ± 37%, P < 0.05 for all 3) treatment. Tgz treatment had no effect on fatty acid transporter protein-1 and membrane-associated plasmalemmal fatty acid-binding protein mRNA expression. We conclude that FFA uptake into cultured muscle cells is, in part, protein mediated and acutely insulin responsive. The basal activity of FFA uptake is impaired in type 2 diabetes. In addition, chronic thiazolidinedione treatment increased FFA uptake and oxidation into cultured human skeletal muscle cells in concert with upregulation of FAT/CD36 expression. Increased FFA uptake and oxidation may contribute to lower circulating FFA levels and reduced insulin resistance in skeletal muscle of individuals with type 2 diabetes following thiazolidinedione treatment.

show abstract

Palmitic acid metabolism in the soleus muscle in vitro in hypo- and hyperthyroid rats

Górecka

Synak

Langfort

et al. 2004

Pflugers Arch - Eur J Physiol

View full text Add to dashboard Cite

The aim of this study was to establish whether the rate of fatty acid (FA) incorporation and its utilization by the isolated soleus muscle is modified under conditions of thyroid hormone deficit or excess. The rate of palmitic acid (PA) uptake, oxidation and incorporation into intramuscular lipids with increasing PA concentration (0.5-1.5 mM) in the incubation medium were determined. In hypothyroid rats intramuscular triacylglycerol (TG) synthesis was increased, while the rate of PA oxidation to CO2 and incorporation into mono- and diacylglycerols (MG/DG) and phospholipids (PL) remained unchanged. In rats with triiodothyronine (T3) excess the rate of all processes studied was enhanced, although the percentage incorporation of PA into different classes of intramuscular lipids was fairly constant and, independently of thyroid state and FA concentration in the medium, was 56-66% for TG, 9-14% for MG/DG and 24-32% for PL. Our results thus indicate that even short-term T3 excess accelerates the rate of FA uptake and metabolism in the oxidative soleus muscle, whereas in hypothyroid rats only intramuscular TG synthesis is affected.

show abstract

Palmitic acid uptake by the rat soleus muscle in vitro

Cited by 5 publications

References 25 publications

Oleic acid uptake by in vitro English sparrow skeletal muscle

Oleic acid uptake by in vitro English sparrow skeletal muscle

Thiazolidinediones upregulate impaired fatty acid uptake in skeletal muscle of type 2 diabetic subjects

Palmitic acid metabolism in the soleus muscle in vitro in hypo- and hyperthyroid rats

Contact Info

Product

Resources

About