The activities of monoamine oxidase-A and-B, succinate dehydrogenase and acid phosphatase in the rat brain after hemitransection

Abstract

The activities of monoamine oxidase-A and -B were determined in four brain regions (limbic system, occipito-temporal cortex, hemispheres and striatum) of the rat 0, 3, 6, 9 and 14 days after hemitransection of the left side. No larger or consistent change in the activity of monoamine oxidase-A towards 5-hydroxytryptamine was found for the left (hemitransected) side with respect to the right side for any of the rats. The monoamine oxidase-B activity towards beta-phenethylamine increased in the left side striatum to a significant level by 3 days, and in the hemispheres and occipito-temporal cortex on the left side, with respect to the right side by 9 days, but no significant changes were found for the limbic system. A small decrease in the activity of succinate dehydrogenase was found in the striatum on the left side by 9 days after hemitransection, but no change in the activity of acid phosphatase was found in this brain region.

Intra- and extraneuronal monoamineoxidase-A and -B activities after central axotomy (hemisection) on rats

“…Estimated by the conventional, high substrate concentration, technique, the MAO-B activity was increased about 40 % on the lesioned side (Table 3) which is of the same order of magnitude as in earlier reports Carlsson et al, 1981). Using the low substrate concentration technique, this increase could be shown to be due entirely to an increase in extraneuronal MAO-B activity.…”

“…Such a decrease has previously been found in the rat (Strolin-Benedetti and Keane, 1980; Oreland et al, 1984) but not in the human brain (Fo~ler et aL, 1980 b) with aging. Neither was such a decrease found in our previous studies on hemitransection of rat brains Carlsson et al, 1981). The difference in the results between rat and human brain MAO-A in aging may be explained by the considerably higher proportion of MAO-A/-B in the rat brain in general and particularly with respect to the abundance ofMAO-A intra-DAneuronally within rat n. caudatus (Oreland et al, 1983 a, b).…”

“…This change was further accelerated in patients with Alzheimer's disease (Adolfsson et al, 1980) and Huntington's disease (Mann et al, 1980). A decreased MAO-A/-B ratio has also been found in rat brains where a central axotomy had been performed Carlsson et al, 1981). In all those cases, however, the most important cause of the changed MAO-A/-B activity ratio was found to be an increase in MAO-B, rather than a decrease in MAO-A activity.…”

Effects of neonatal bilateral eye enucleation on postnatal development of the monoamines in posterior thalamus of the rat

“…Our results showed a decrease in the MAO-A/MAO-B ratio in enucleated rats versus controls. A decrease in the MAO-A/MAO-B activity ratio has been found in rat brain where a central axotomy had been performed (Oreland et al, 1980;Carlsson et al, 1981).…”

Intra- and Extraneuronal Monoamine Oxidase

“…Such neurone loss oc curs after hemitransection in the rat, and with age in the rat and in man, and in all these cases a decrease in the ratio of activities of MAO-A/MAO-B is found [see e.g. 16,17].…”