PMID: 6108991Jul 1, 1980Paper

Tyrosine hydroxylase regulation: apparent kinetic alterations following incubation of brain slices in a sodium-free medium

Journal of Neurochemistry
G BustosR H Roth

Abstract

In an attempt to determine if alterations in intraneuronal Ca2+ may regulate tyrosine hydroxylase activity, brain slices were subjected to experimental manipulations known to increase the intraneuronal concentration of free Ca2+ ions. Incubation of either striatal or olfactory tubercle slices in a Na+-free medium for 15 min at 37 degrees resulted in a marked increase in the activity of tyrosine hydroxylase present in the 20,000 g supernatant fraction of homogenates prepared from the slices. Tyrosine hydroxylase isolated from slices previously incubated in a Na+-free, choline-enriched medium or in a Na+-free, sucrose-enriched medium exhibited maximal activities when assayed at pH 6.0 and 7.0, respectively. However, the percentage stimulation of enzyme activity induced by incubation of the slices in a Na+-free medium was maximal when the enzyme assays were performed at pH 7.0. The observed increase in enzyme activity seems to be mediated by a decrease in the apparent Km of the enzyme for pteridine cofactor, regardless of whether the kinetic enzyme analyses were conducted at pH 6.0 or 7.0, and by an increase in the Ki of the enzyme for end-product inhibitor dopamine. The apparent kinetic changes in the enzyme do not seem to result...Continue Reading

References

Apr 28, 1978·Annals of the New York Academy of Sciences·M P BlausteinN K Kendrick
Aug 1, 1975·Proceedings of the National Academy of Sciences of the United States of America·W LovenbergI Hanbauer
Jan 15, 1976·Biochemical Pharmacology·K GyslingG Martínez
Jan 1, 1972·Progress in Biophysics and Molecular Biology·P F Baker
Aug 15, 1970·Life Sciences. Pt. 1: Physiology and Pharmacology·M GoldsteinR Frenkel
Oct 1, 1972·Journal of Neurochemistry·W L Stahl, P D Swanson
Sep 1, 1972·British Journal of Pharmacology·G Bustos, R H Roth
Mar 1, 1971·Journal of Neurochemistry·W L Stahl, P D Swanson
Aug 1, 1953·The Biochemical Journal·M DIXON

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Citations

Sep 15, 1981·Biochimica Et Biophysica Acta·K OkaT Nagatsu
Oct 1, 1985·Pharmacology, Biochemistry, and Behavior·D SutooK Iimura
Oct 1, 1986·Pharmacology, Biochemistry, and Behavior·D E Walters, L A Carr
Mar 1, 1989·Brain Research Bulletin·D SutooM Geffard
May 22, 2003·Neurobiology of Disease·Den'etsu Sutoo, Kayo Akiyama
Jan 1, 1983·Annual Review of Biochemistry·L F Reichardt, R B Kelly
Aug 1, 1982·Journal of Neurochemistry·G Kapatos, M J Zigmond
Feb 27, 2001·Journal of Neuroscience Research·D SutooK Yabe
Nov 1, 1988·Pharmacological Research Communications·A H Tissari

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