Fatty acid uptake by isolated rat heart myocytes represents a carrier-mediated transport process.
AUTOR(ES)
Stremmel, W
RESUMO
The mechanism by which fatty acids enter cardiomyocytes is unclear. Therefore, the influx kinetics of [3H]oleate into isolated rat heart myocytes were examined. Cells were incubated at 37 degrees C with [3H]oleate bound to albumin in various molar ratios and the initial rate of uptake (V0) was determined as a function of the unbound oleate concentration in the medium. V0 was saturable with increasing oleate concentrations incubated (Km 78 nM; Vmax 1.9 nmol X min-1 per 10(6) cells) and temperature dependent with an optimum at 37 degrees C. Furthermore, binding of [3H]oleate to isolated plasma membranes of cardiomyocytes was saturable, revealing a KD of 42 nM, and was inhibited by heat denaturation or trypsin pretreatment of the membranes. From these membranes a single 40-kD protein with high affinity for a variety of long chain fatty acids was isolated. With a monospecific antibody to this membrane protein, binding as well as cellular influx of [3H]oleate was selectively inhibited. These data indicate that at least a portion of myocardial fatty acid uptake is mediated by a specific membrane protein.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=442535Documentos Relacionados
- tRNA transport from the nucleus in a eukaryotic cell: carrier-mediated translocation process.
- Intestinal elimination of ofloxacin enantiomers in the rat: evidence of a carrier-mediated process.
- Sinusoidal efflux of glutathione in the perfused rat liver. Evidence for a carrier-mediated process.
- Light-induced, carrier-mediated transport of tetracycline by Rhodopseudomonas sphaeroides.
- Carrier-Mediated Transport of Folate in a Mutant of Pediococcus cerevisiae