Apical and basolateral 4F2hc and the amino acid exchange of L-DOPA in renal LLC-PK1 cells

• Type: Article in International Scientific Journal
• Date: 2005

Authors

soares-da-silva, p (Author) FMUP; Maria Paula Serrão (Author) FMUP

Journal

Title: Amino Acids

Vol. 29

Pages: 213-219

ISSN: 0939-4451

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 2 Citations

Scopus - 3 Citations

Other information

Authenticus ID: P-000-0JA

DOI: 10.1007/s00726-005-0242-5

Abstract (EN): The present study aimed to examine the presence and define the role of 4F2hc, a glycoprotein associated with the LAT2 amino acid transporter, in L-DOPA handling by LLC-PK1 cells. For this purpose we have measured the activity of the apical and basolateral inward and outward transport of [C-14] L-DOPA in cell monolayers and examined the influence of 4F2hc antisense oligonucleotides on [C-14] L-DOPA handling. The basal-to-apical transepithelial flux of [C-14] L-DOPA progressively increased with incubation time and was similar to the apical-to-basal transepithelial flux. The spontaneous and the L-DOPA-stimulated apical fractional outflow of [C-14] L-DOPA were identical to that through the basal cell side. The L-DOPA-induced fractional outflow of [C-14] L-DOPA through the apical or basal cell side was accompanied by marked decreases in intracellular levels of [C-14] L-DOPA. In cells treated with an antisense oligonucleotide complementary to 4F2hc mRNA for 72h, [C-14] L-DOPA inward transport and 4F2hc expression were markedly reduced. Treatment with the 4F2hc antisense oligonucleotide markedly decreased the spontaneous fractional outflow of [C-14] L-DOPA through the apical or the basal cell side. It is likely that the Na+-independent and pH-sensitive uptake of L-DOPA include the hetero amino acid exchanger LAT2/4F2hc, which facilitates the trans-stimulation of L-DOPA and its outward transfer at both the apical and basal cell sides.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7