Monoamine oxidase isoenzymes in rat brain: differential changes during postnatal development but not aging.
Differential development of monoamine oxidase (MAO) isoenzymes in rat whole brain is described in postnatally developing Sprague-Dawley rats. Total MAO and isoenzyme activity was measured using nonspecific and specific substrates. Total MAO activity measured using tyramine, increased postnatally up to 24 weeks of age and attained a plateau afterward. The increase in total MAO activity was significant at all age groups (18 days to 36 months) investigated as compared to new born rats. MAO-A and MAO-B activities were measured using octopamine and benzylamine respectively. We also observed a marginal increase of MAO-A activity and a significant increase of MAO-B activity upon development. Furthermore, at 12 weeks of age, MAO-B activity increased by 10-fold as compared to new born and was consistent up to 36 months of age. The qualitative localization of the enzyme activity on non SDS-PAGE by nitroblue tetrazolium staining confirmed the increase of MAO-B during the development. It is suggested that the maturational increase of total MAO activity in brain is predominantly due to the increase of MAO-B isoenzyme.
Department of Neurochemistry, National Institute of Mental Health and Neurosciences, Bangalore, India.
K
K
Rao
S N
SN
Nagendra
M N
MN
Subhash
D000375:Aging / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000201:enzymology* / Q000254:growth & development; D004591:Electrophoresis, Polyacrylamide Gel; D007527:Isoenzymes / Q000378:metabolism*; D008297:Male; D008995:Monoamine Oxidase / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
D007527:Isoenzymes; D008995:Monoamine Oxidase