The
isoprenoid pathway produces
digoxin, an endogenous membrane Na(+)-K+
ATPase inhibitor and regulator of
neurotransmitter transport. The objective of the study was to relate
digoxin status and hemispheric dominance to the pathogenesis of
psychiatric disorders--
bipolar mood disorder,
major depressive disorder, and
schizophrenia. The following parameters were assessed in
bipolar mood disorder during the manic phase and depressive phase of the illness as well as in
major depressive disorder, and
schizophrenia:
HMG CoA reductase activity,
tryptophan and
tyrosine catabolic patterns, red blood cell (RBC) Na(+)-K+
ATPase activity, and serum
magnesium. These parameters were compared to individuals of differing hemispheric dominance. The levels of serum
digoxin and
HMG CoA reductase activity were found to be decreased in the depressive phase of
bipolar mood disorder and
major depressive disorder with a corresponding increase in RBC Na(+)-K+
ATPase activity and serum
magnesium levels. There was increase in
tyrosine and
tyrosine catabolites, and a reduction in
tryptophan and its catabolites, in the serum in the depressive phase of
bipolar mood disorder and
major depressive disorder. The
neurotransmitter patterns and
digoxin levels in the depressive phase of
bipolar mood disorder/
major depressive disorder correlated with those in right-handed/left hemisphere dominant individual. The
neurotransmitter patterns and
digoxin levels in the manic phase of
bipolar mood disorder and
schizophrenia correlated with those in left-handed/right hemisphere dominant individuals.
Digoxin status and hemispheric dominance could correlate with the pathogenesis of
psychiatric disorders--
schizophrenia,
major depressive disorder, and
bipolar mood disorder.