QueryDate : 2016-12-24
Cites : 0
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Data source : Google Scholar QueryDate : 2016-12-24 Cites : 0 |
Alterations in
brain creatine levels are considered to be associated with various
pathological conditions. However, there is still no exact evidence on
character of this changes and clear link between disorders and upstream
and downstream direction of creatine changes.
Chronic mental stress conditions are thought to be connected with
upstream regulation of cellular oxidative pathways, thus oxidizing
various structural and active compounds. Oxidative stress also takes
part in increase of permeability of blood brain barrier (BBB) that, in
turn, makes it possible for a number of molecules to cross the BBB in
both directions.
Observations on long-term social isolation and circadian rhythm
violation show a rising trend in brain creatine amount, while there was
remarkable down-regulation in creatine synthesizing system, as the
key-enzymes’ (AGAT and GAMT) activity was decreased.
Investigations of BBB permeability for creatine under the stress
conditions by mass-spectrometric analyses revealed no changes in
creatine transport in the stress group, compared to the control.
However, the activity of mitochondrial CK was reduced for about 25% and
Vmax had fallen down in the stressed group, the Km was not drastically
changed.
To sum up, it could be supposed that the reason for the elevations of
creatine levels in brain under the mental stress conditions could be
stimulated by the activated oxidative stress that induces
conformational changes in mitochondrial Creatine Kinase structure and
decreasing the ability of enzyme to phosphorylate the creatine and as a
result free creatine levels in brain are being arisen.
