Abstract
The transport of the eight amino acids (phenylalanine, tyrosine, tryptophan, valine, leucine, isoleucine, histidine and methionine) using the large neutral amino acid transporter of the blood-brain barrier (BBB) has been calculated using published kinetic data. The fate of the amino acids has been followed from blood to interstitial space, to cell and through metabolism which included, for tyrosine and tryptophan, the hydroxylases. The system was analysed in terms of flux control coefficients. Since the summation theorem did not hold, the system clearly behaved as a non-homogeneous system. At physiological levels of these eight amino acids, the largest contribution to the control of the flux of tyrosine is given by the hydroxylase step, followed by the diffusional component of the transport across the BBB. For tryptophan it is the hydroxylase step, followed by the carrier-mediated transport across the BBB. For the other amino acids it is the metabolism, followed by the diffusional component of the BBB transport. These parameters for tyrosine and tryptophan were determined at increased levels of blood phenylalanine, tyrosine or histidine. The flux through tryptophan hydroxylase can be affected by high blood levels of tyrosine an...Continue Reading
References
Apr 1, 1978·Journal of Neurochemistry·A V MackayC M Yates
Oct 1, 1979·Biochemical Society Transactions·H Kacser, J A Burns
Jan 1, 1977·Journal of Neurochemistry·W M Pardridge
Aug 5, 1975·Biochimica Et Biophysica Acta·W M Pardridge, W H Oldendorf
May 1, 1985·European Journal of Pediatrics·H C LouA Niederwieser
Jul 1, 1987·Acta paediatrica Scandinavica·H C LouP Bruhn
Aug 15, 1987·Archives of Biochemistry and Biophysics·T J Nelson, S Kaufman
Dec 1, 1988·European Journal of Pediatrics·C LykkelundF Güttler
Jan 1, 1989·Journal of Inherited Metabolic Disease·F A Hommes
Jul 20, 1985·Lancet·H Lou
Mar 15, 1986·The Biochemical Journal·M SalterC I Pogson
Aug 1, 1988·Acta Paediatrica Japonica; Overseas Edition·C R Scriver
Jun 15, 1988·European Journal of Biochemistry·C Giersch
Jan 2, 1987·Neuroscience Letters·M EhretM Maitre
May 15, 1987·European Journal of Biochemistry·H M SauroD A Fell
Nov 1, 1987·Journal of Neurochemistry·Q R SmithS I Rapoport
Nov 1, 1986·Pediatric Research·W KrauseL Elsas
Jan 1, 1985·The Journal of Clinical Investigation·W KrauseL Elsas
Mar 17, 1986·European Journal of Biochemistry·J H HofmeyrK J van der Merwe
Feb 15, 1974·European Journal of Biochemistry·R Heinrich, T A Rapoport
May 1, 1965·Biochemical Pharmacology·S UdenfriendT Nagatsu
Jan 1, 1983·Journal of Inherited Metabolic Disease·C R Scriver, H L Levy
Jan 1, 1983·Journal of Inherited Metabolic Disease·J T CoulombeC R Scriver
Oct 1, 1983·Physiological Reviews·W M Pardridge
Jan 1, 1983·Journal of Inherited Metabolic Disease·A RosenmannH L Levy
Jan 1, 1981·Neuroscience and Biobehavioral Reviews·C V VorheesH K Berry
Aug 1, 1984·European Journal of Pediatrics·K TadaM Takesada
Feb 1, 1982·European Journal of Biochemistry·H Nakata, H Fujisawa
Oct 1, 1982·The Journal of Pediatrics·K TadaH Naruse
Jan 5, 1981·Life Sciences·M C Morre, R J Wurtman
Jan 1, 1981·Advances in Experimental Medicine and Biology·G Curzon
Citations
Feb 1, 1992·Amino Acids·M Hjelm, J Seakins
Jan 1, 1990·Journal of Inherited Metabolic Disease·F A Hommes, J S Lee
Oct 1, 1995·Pharmacology, Biochemistry, and Behavior·V CastagneM Gyger
Dec 1, 1996·Pharmacology, Biochemistry, and Behavior·V CastagneM Gyger
Dec 1, 1991·Biochemical Medicine and Metabolic Biology·F A Hommes
Jun 28, 2000·Molecular Genetics and Metabolism·W B HanleyJ T Clarke
Dec 2, 2015·PloS One·Danique van VlietFrancjan J van Spronsen
Nov 11, 1998·Journal of Cerebral Blood Flow and Metabolism : Official Journal of the International Society of Cerebral Blood Flow and Metabolism·H E MöllerK Ullrich
Jan 1, 1991·AORN Journal·J L Bensen, W McClellan
Jan 1, 1995·Leukemia & Lymphoma·P Carde
Feb 12, 1998·Brain Research·H E MöllerK Ullrich