Rao K, Nagendra S N, Subhash M N
Department of Neurochemistry, National Institute of Mental Health and Neurosciences, Bangalore, India.
Neurobiol Aging. 1995 Sep-Oct;16(5):833-6. doi: 10.1016/0197-4580(95)00061-i.
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.
本文描述了出生后发育的斯普拉格-道利大鼠全脑中单胺氧化酶（MAO）同工酶的差异发育情况。使用非特异性和特异性底物测量总MAO和同工酶活性。用酪胺测量的总MAO活性在出生后至24周龄时升高，之后达到平稳状态。与新生大鼠相比，在所有研究的年龄组（18天至36个月）中，总MAO活性的增加均具有显著性。分别用章鱼胺和苄胺测量MAO-A和MAO-B的活性。我们还观察到发育过程中MAO-A活性略有增加，MAO-B活性显著增加。此外，在12周龄时，MAO-B活性相较于新生大鼠增加了10倍，且在36个月龄时保持一致。通过硝基蓝四唑染色在非SDS-PAGE上对酶活性进行定性定位，证实了发育过程中MAO-B的增加。提示脑内总MAO活性的成熟性增加主要归因于MAO-B同工酶的增加。
