Regulation of L-leucine transport in rat kidney by dexamethasone and triiodothyronine

被引：0
作者：
M. Schwertfeger
K. Pissowotzki
Ch. Fleck
P. M. Taylor
机构：
[1] Institute of Pharmacology and Toxicology,
[2] University of Jena,undefined
[3] Germany,undefined
[4] ,undefined
[5] Department of Anatomy and Physiology,undefined
[6] University of Dundee,undefined
[7] Scotland,undefined
[8] United Kingdom,undefined
来源：
Amino Acids | 2003年 / 25卷
关键词：
Keywords: Amino acid transport; Kidney; Glucocorticoid hormones; Thyroid hormones; Leucine;
D O I：
暂无
中图分类号：
学科分类号：
摘要：
 We have investigated the transport mechanisms involved in the stimulation of renal tubular reabsorption of large amino acids by glucocorticoids in vivo through the examination of activity and expression of specific transport systems L and y+L for L-leucine in membrane preparations of rat kidneys. Kidneys were removed from adult female Wistar rats treated with dexamethasone or triiodothyronine, and the fractions of brush-border and basolateral membranes were isolated by density gradient centrifugation. Functional analysis of L-leucine uptake using rapid filtration technique revealed induction of a sodium-dependent, arginine-inhibitable system y+L transport component in the basolateral membrane in the dexamethasone-treated group. A minor sodium-independent, BCH-inhibitable, system L transport component was unaffected by glucocorticoids. L-leucine uptake remained unaffected in the triiodothyronine-treated group. Expression of both subunits of the system y+L transporter was increased in dexamethasone-treated rat kidneys: Western blot analysis showed a significant (46%) increase of 4F2hc protein abundance in the basolateral membrane fraction and competitive RT-PCR revealed an almost 4-times induced expression of y+LAT1 mRNA. Our results indicate that system y+L in rat kidney is regulated by glucocorticoids. We suggest that enhancement of both 4F2 heavy chain and y+LAT1 light chain is necessary for induction of this transport system in the kidney.
引用
收藏
页码：75 / 83
页数：8
相关论文
共 199 条
  • [1] Bertran J(1992)Expression cloning of a human renal cDNA that induces high affinity transport of L-cystine shared with dibasic amino acids in Xenopus oocytes J Biol Chem 268 14842-14849
  • [2] Werner A(1995)The 4F2hc surface antigen is necessary for expression of system L-like neutral amino acid-transport activity in C6-BU-1 rat glioma cells: evidence from expression studies in Xenopus laevis oocytes Biochem J 15 863-28848
  • [3] Chillaron J(1999)Identification of an amino acid transporter associated with the cystinuria-related type II membrane glycoprotein J Biol Chem 274 28845-488
  • [4] Nunes V(1992)Role of intestinal basolateral membrane in absorption of nutrients Am J Physiol 263 482-101
  • [5] Biber J(1979)Exploiting amino acid structure to learn about membrane transport Adv Enzymol 49 41-3616
  • [6] Testar X(1990)Role of amino acid transport and counter transport in nutrition and metabolism Physiol Rev 70 43-501
  • [7] Zorzano A(1965)The use of N-methylation to direct route of mediated transport of amino acids J Biol Chem 240 3609-177
  • [8] Estivill X(1992)Identification of a new transport system (y+L) in human erythrocytes that recognizes lysine and leucine with high affinity J Physiol 454 491-8751
  • [9] Murer H(2000)Surface antigen 4F2: not a single membrane protein, but a family of proteins with multiple functions J Membr Biol 173 165-1092
  • [10] Palacin M(1998)The amino acid transport system y+L/4F2hc is a heteromultimeric complex FASEB J 12 1319-18661
12345678910