Int J Neurosci. 2003;113(12):1705-1717
Kurup RK, Kurup PA.
Department of Neurology, Medical College Hospital, Trivandrum, Kerala, India.
Psychiatric abnormalities have been described in primary neurological disorders like multiple sclerosis, primary generalized epilepsy, Parkinson's disease, subacute sclerosing panencephalitis (SSPE), central nervous system glioma, and syndrome X with vascular dementia.
It was therefore considered pertinent to compare monoamine neurotransmitter pattern in schizophrenia with those in the disorders described above.
The end result of neurotransmission is changes in membrane Na+-K+ ATPase activity.
Membrane Na+-K+ ATPase inhibition can lead to magnesium depletion, which can lead to an upregulated isoprenoid pathway.
The isoprenoid pathway produces three important metabolites--digoxin, an endogenous membrane Na+ -K+ ATPase inhibitor; ubiquinone, a membrane antioxidant and component of mitochondrial electron transport chain; and dolichol, important in N-glycosylation of protein.
The serum/plasma levels of digoxin, dolichol, ubiquinone, magnesium, HMG CoA reductase activity, and RBC Na+-K+ ATPase activity were estimated in all these disorders.
The result showed that the concentration of serum tryptophan and serotonin was high and serum tyrosine, dopamine, adrenaline, and noradrenaline low in all the disorders studied.
The plasma HMG CoA reductase activity, serum digoxin, and serum dolichol levels were high and serum ubiquinone levels, serum magnesium, and RBC Na+-K+ ATPase activity were low in all the disorders studied.
The significance of these changes in the pathogenesis of syndrome X, multiple sclerosis, primary generalized epilepsy, schizophrenia, SSPE, and Parkinson's disease is discussed in the setting of the interrelationship between these disorders documented in literature.