Determination of glutamic acid decarboxylase activity in rat brain

✍ Scribed by P.J. Lupien; C.M. Hinse; L. Berlinguet

• Publisher: Elsevier Science
• Year: 1968
• Tongue: English
• Weight: 424 KB
• Volume: 24
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(68)90053-5

✦ Synopsis

Since the decarboxylation of glutamic acid into y-aminobutyric acid (GABA) involves a release of COz, we easily understand the widespread use of manometric methods for the determination of glutamic acid decarboxylase activity (GADA) (l-13,29,30).

Other investigators (14-16) have chosen to measure GADA by determining the amount of GABA produced rather than the amount of CO* released, using the fluorometric method of Lowe et al. ( 27) or chromatography (17)(18)(19), the latter method gaining popularity with the arrival of isotopes (20,21).

The present paper describes a simple isotopic method for the determination of glutamic acid decarboxylase activity in rat brain. MATERIALS L-Glutamic acid-l-14C, 3.6 mc/mmole, was purchased from Calbiothem, Liquifluor from Nuclear-Chicago Corp., and hydroxide of Hyamine 10-X from Packard Instrument Co.

The radioactivity counter was a Nuclear-Chicago series 720 liquid scintillation counter, and the vials for liquid scintillaton were purchased from Wheaton, Millville, N. 6. The Warburg flasks had a capacity of 15 ml, were made of borosilate, :md had a venting plug.