digoxin and Schizophrenia

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.

Topics: Adult; Bipolar Disorder; Depressive Disorder, Major; Digoxin; Dominance, Cerebral; Humans; Hydroxymethylglutaryl CoA Reductases; Magnesium; Sampling Studies; Schizophrenia; Sodium-Potassium-Exchanging ATPase; Tryptophan; Tyrosine

The isoprenoid pathway and its metabolites--digoxin, dolichol and ubiquinone were assessed in schizophrenia. There was an upregulation of the isoprenoid pathway as evidenced by elevated HMG CoA reductase activity. Digoxin, an endogenous Na+-K+ ATPase inhibitor secreted by the hypothalamus was found to be elevated and RBC membrane Na+-K+ ATPase activity was found to be reduced in schizophrenia. Membrane Na+-K+ ATPase inhibition can result in increased intracellular Ca2+ and reduced magnesium levels. Hypothalamic digoxin can modulate conscious and subliminal perception and its dysfunction may lead on to schizophrenia. Digoxin can also preferentially upregulate tryptophan transport over tyrosine resulting in increased levels of depolarising tryptophan catabolites--serotonin and quinolinic acid (NMDA agonist), and decreased levels of hyperpolarising tyrosine catabolites--dopamine and noradrenaline contributing to membrane Na+-K+ ATPase inhibition. NMDA excitotoxicity could result from hypomagnesemia induced by membrane Na+-K+ ATPase inhibition and quinolinic acid, an NMDA agonist acting on the NMDA receptor. Hypomagnesemia and increased dolichol level can affect glycoconjugate metabolism and membranogenesis leading on to disordered synaptic connectivity in the limbic allocortex and defective presentation of viral antigens and neuronal antigens contributing to autoimmunity and viral persistance important in the pathogenesis. Membrane Na+-K+ ATPase inhibition can produce immune activation, a component of autoimmunity. Mitochondrial dysfunction consequent to altered calcium/magnesium ratios and reduced ubiquinone levels can result in increased free radical generation and reduced free radical scavenging & defective apoptosis leading on to abnormal synaptogenesis. Schizophrenia can thus be considered as a syndrome of hypothalamic digoxin hypersecretion consequent to an upregulated isoprenoid pathway.

Topics: Adult; Consciousness; Digoxin; Dolichols; Enzyme Inhibitors; Female; Humans; Hydroxymethylglutaryl CoA Reductases; Hypothalamus; Male; Middle Aged; Models, Psychological; Schizophrenia; Subliminal Stimulation

Catabolism of tryptophan and tyrosine in relation to the isoprenoid pathway was studied in neurological and psychiatric disorders. The concentration of trytophan, quinolinic acid, kynurenic acid, serotonin and 5-hydroxyindoleacetic acid was found to be higher in the plasma of patients with all these disorders; while that of tyrosine, dopamine, epinephrine and norepinephrine was lower. There was increase in free fatty acids and decrease in albumin (factors modulating tryptophan transport) in the plasma of these patients. Concentration of digoxin, a modulator of amino acid transport, and the activity of HMG CoA reductase, which synthesizes digoxin, were higher in these patients; while RBC membrane Na+-K+ ATPase activity showed a decrease. Concentration of plasma ubiquinone (part of which is synthesised from tyrosine) and magnesium was also lower in these patients. No morphine could be detected in the plasma of these patients except in MS. On the other hand, strychnine and nicotine were detectable. These results indicate hypercatabolism of tryptophan and hypocatabolism of tyrosine in these disorders, which could be a consequence of the modulating effect of hypothalamic digoxin on amino acid transport.

Topics: Adult; Biogenic Monoamines; Brain Diseases; Brain Neoplasms; Digoxin; Epilepsy, Generalized; Erythrocytes; Fatty Acids, Nonesterified; Female; Glioma; Glycine Agents; Humans; Hydroxymethylglutaryl CoA Reductases; Kynurenic Acid; Magnesium; Male; Microvascular Angina; Middle Aged; Morphine; Narcotics; Nicotine; Nicotinic Agonists; Parkinson Disease; Quinolinic Acid; Schizophrenia; Serum Albumin; Sodium-Potassium-Exchanging ATPase; Strychnine; Tryptophan; Tyrosine; Ubiquinone

Two substances which are products of the isoprenoid pathway, can participate in lipid peroxidation. One is digoxin, which by inhibiting membrane Na(+)-K+ ATPase, causes increase in intracellular Ca2+ and depletion of intracellular Mg2+, both effects contributing to increase in lipid peroxidation. Ubiquinone, another products of the pathway is a powerful membrane antioxidant and its deficiency can also result in defective electron transport and generation of reactive oxygen species. In view of this and also in the light of some preliminary reports on alteration in lipid peroxidation in neuropsychiatric disorders, a study was undertaken on the following aspects in some of these disorders (primary generalised epilepsy, schizophrenia, multiple sclerosis, Parkinson's disease and CNS glioma)--1) concentration of digoxin, ubiquinone, activity of HMG CoA reductase and RBC membrane Na(+)-K+ ATPase 2) activity of enzymes involved in free radical scavenging 3) parameters of lipid peroxidation and 4) antioxidant status. The result obtained indicates an increase in the concentration of digoxin and activity of HMG CoA reductase, decrease in ubiquinone levels and in the activity of membrane Na(+)-K+ ATPase. There is increased lipid peroxidation as evidenced from the increase in the concentration of MDA, conjugated dienes, hydroperoxides and NO with decreased antioxidant protection as indicated by decrease in ubiquinone, vit E and reduced glutathione in schizophrenia, Parkinson's disease and CNS glioma. The activity of enzymes involved in free radical scavenging like SOD, catalase, glutathione peroxidase and glutathione reductase is decreased in the above diseases. However, there is no evidence of any increase in lipid peroxidation in epilepsy or MS. The role of increased operation of the isoprenoid pathway as evidenced by alteration in the concentration of digoxin and ubiquinone in the generation of free radicals and protection against them in these disorders is discussed.

Topics: Central Nervous System Neoplasms; Digoxin; Epilepsy, Generalized; Free Radicals; Glioma; Humans; Lipid Peroxidation; Multiple Sclerosis; Nervous System Diseases; Parkinson Disease; Schizophrenia; Ubiquinone

Topics: Adult; Aldosterone; Antidepressive Agents, Tricyclic; Antipsychotic Agents; Blood Proteins; Cardenolides; Case-Control Studies; Creatinine; Digoxin; Dopamine; Dopamine Antagonists; Female; Humans; Lithium; Male; Mood Disorders; Radioimmunoassay; Renin-Angiotensin System; Saponins; Schizophrenia; Sodium-Potassium-Exchanging ATPase; Water-Electrolyte Balance

Topics: Chlorpromazine; Digoxin; Humans; Platelet Aggregation; Schizophrenia

Topics: Adolescent; Adult; Brain Injuries; Diagnosis, Differential; Digoxin; Electroconvulsive Therapy; Encephalitis; Extrapyramidal Tracts; Female; Humans; Hyperkinesis; Hysteria; Male; Meclofenoxate; Middle Aged; Parkinson Disease, Postencephalitic; Schizophrenia; Time Factors; Tranquilizing Agents