The effects of aging on MAO activity and amino acid levels in rat brain
The possibility that age-related changes in amino acid levels in various rat brain areas might correlate with modifications of monoamine oxidase (MAO) activity, already found with aging, has been examined.
Taurine, aspartic acid and glutamic acid levels were found to be unchanged or decreased with age, whereas GABA and glutamine concentrations increased or remained unchanged. Serine and glycine (except in pons-medulla) levels were found to be unaffected by age. The increase in total MAO activity with aging in some brain areas might contribute to the changes in amino acid levels. Likewise, the possible influence of age-induced changes in activity of various enzymes involved in H2O2 and NH3 detoxication and in amino acid biosynthesis on rat brain amino acid levels are considered. Oral administration of clorgyline or 1-deprenyl to young rats did not significantly modify the concentrations of most brain amino acids.
KeywordsHepatic Encephalopathy Amino Acid Level Glutamine Synthetase Activity Brain Ammonia Taurine Chloramine
Unable to display preview. Download preview PDF.
- Aprison MH, Daly EC (1978) Biochemical aspects of transmission at inhibitory synapses: the role of glycine. Adv Neurochem 3: 203–294.Google Scholar
- Aprison MH, Nadi NS (1978) Glycine: inhibition from the sacrum to the medulla. NATO Adv Study Inst Ser (Ser A): 531-570.Google Scholar
- Cao Danh H, Strolin Benedetti M, Dostert P (1984) Differential changes in monoamine oxidase A and B activity in aging rat tissues. In: Tipton KF, Dostert P, Strolin Benedetti M (eds) Monoamine oxidase and disease. Prospects for therapy with reversible inhibitors. Academic Press, London, pp 301–317.Google Scholar
- Davis J, Himwich WA (1975) Neurochemistry of the developing and aging mammalian brain. Adv Behav Biol 16: 329–357.Google Scholar
- Kanungo MS, Kaur G (1969) Regulatory changes in enzymes as a function of age of the rat. Proceedings of the 8th International Congress of Gerontology, vol 1. pp 356–359.Google Scholar
- Strolin Benedetti M, Cao Danh H, Dostert P (1986) Age-related changes in brain MAO and in enzymes involved in detoxication processes of MAO-generated compounds. In: Biggio G, Spano PF, Toffano G, Gessa GL (eds) Modulation of central and peripheral transmitter function. Liviana Press, Padova, pp 255–267.Google Scholar