ISSN:
1573-6865
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Methodological aspects of the histochemical technique for the demonstration of succinate semialdehyde dehydrogenase activity (EC 1.2.1.24) (indicative of the degradative step of γ-aminobutyric acid catabolism) have been analysed in rat Purkinje neurons, where γ-aminobutyric acid has been shown to be a neurotransmitter, and in hepatocytes, where it is metabolized. During a histochemical incubation for the enzyme, artefacts of succinate dehydrogenase activity and the ‘nothing dehydrogenase’ reaction are produced. Inhibition of these artefacts by the addition of two inhibitors, malonate andp-hydroxybenzaldehyde, revealed specific reaction products. Formazan granules, which can be ascribed only to specific succinate semialdehyde dehydrogenase activity, are obtained by adding malonate to the incubation medium in order to inhibit both succinate dehydrogenase activity and nothing dehydrogenase. The formation of these granules is completely inhibited byp-hydroxybenzaldehyde, and inhibitor of succinate semialdehyde dehydrogenase activity. Different levels of succinate semialdehyde dehydrogenase activity were noted in Purkinje neurons. This activity was also found in hepatocytes, mostly in the portal area, but with a lesser degree of intensity and specificity. Indeed, non-specific formazan granules were still produced, because of the ‘nothing dehydrogenase’ reaction, even in the presence of malonate. Thus, a malonate-insensitive ‘nothing dehydrogenase’ reaction seems to be present in neural and hepatic tissues.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01002737
Permalink
