Plasma cyclic AMP in manic-depressive illness

Plasma cyclic AMP in non-abstinent chronic alcoholics. Relation to clinical parameters

Plasma cyclic AMP levels were determined in a group of 36 male chronic alcoholics during a period of their usual alcohol intake and compared to 29 normal controls. Significantly lower values (P less than 0.005) were found in the patient group. The possible influence of age, chronicity of drinking, family history of alcoholism, dementia and liver injury on plasma cAMP levels was examined by multiple regression analysis. No influence of those factors could be established except that demented alcoholics showed a trend toward higher levels than a non-demented subgroup. The role of reduced beta-adrenergic receptor activity during chronic alcohol ingestion is discussed in relation to the above findings.

The neurochemistry of mania. The effect of lithium on catecholamines, indoleamines and calcium mobilization

In an attempt to elucidate the chemical pathology of mania one has to consider the pharmacology of the two most effective treatments for this illness: lithium and the neuroleptics. Some of the possible mechanisms of action of these drugs on catecholamine and indoleamine mechanisms are discussed. The majority of this article is based on my and my colleagues' work which has been carried out in this MRC Laboratory on the effect of lithium on biological variates in bipolar patients and the effects of the administration of antidepressant treatments in these patients. It is concluded that lithium has a similar action on these mechanisms in both unipolar and bipolar patients which might suggest a common pathology in both unipolar and bipolar illness. It is suggested that in order to maintain an euthymic state in a bipolar patient one should maintain a certain degree of sensitivity of 5-HT2 receptors. This sensitivity may be related to the activity of calcium channels and to the polyphosphoinositide system. The former system can be regulated by the administration of calcium channel antagonists which have been shown to be effective in the treatment of mania. The polyphosphoinositide system is one that can be regulated by therapeutic concentrations of lithium. It is concluded that co-administration of a calcium channel antagonist and lithium may be a very effective treatment for mania.

Plasma cyclic AMP and cyclic GMP in childhood-onset psychoses

Plasma cyclic AMP is a "second messenger" that may reflect levels of activity of important neurotransmitter receptors. Plasma cyclic AMP was measured in 18 patients with childhood autism, 7 patients with pervasive developmental disorder, and 12 age- and sex-matched healthy controls. Plasma cyclic AMP was significantly elevated by over 100% in both groups of patients with childhood-onset psychoses compared with controls. Plasma cyclic GMP, a nucleotide linked to different receptors, was not elevated, suggesting that the finding may be specific.

Brain purinergic activity linked with depressive symptomatology: hypoxanthine and xanthine in CSF of patients with major depressive disorders

The purine metabolites hypoxanthine and xanthine were analyzed in cerebrospinal fluid (CSF) of 70 patients with major depressive disorders (diagnosed according to Research Diagnostic Criteria) and, for reference, in 26 nonpsychiatric individuals. In the patient group, levels adjusted by analysis of covariance to same sex, age, height, and weight were univariately and multivariately correlated with both depressive subdiagnoses and individual depressive symptoms. Results indicate that raw CSF levels in depressed patients are significantly correlated with the four variables used in adjustment (for hypoxanthine mainly negatively with height; for xanthine mainly positively with age). Hypoxanthine and xanthine both appear to be linked with the expression of depressive symptomatology: lower levels of hypoxanthine are associated with anger and suicidal tendencies, and higher levels are related to memory disturbance; lower xanthine levels characterize patients with subjective feelings of depression, and in patients with higher levels appetite is poor.

Plasma cyclic AMP level in psychiatric diseases of childhood

Determinations were made of the plasma cyclic AM level to examine its relationship with hyperkinesis (Werry-Weiss-Peters Activity Scale, WWPAS) and other features of mental disorders in 80 children, of whom 21 had early infantile autism, 15 hyperkinetic mental retardation, 12 minimal brain dysfunction and 32 Down's syndrome. In autistic and hyperkinetic mentally retarded children, the plasma cyclic AMP levels were higher than in normal children and were positively correlated with the WWPAS score. In children with minimal brain dysfunction, the plasma cyclic AMP level was significantly lower than in normal children and was not correlated with the WWPAS score. In children with Down's syndrome, the plasma cyclic AMP level was somewhat higher than in normal children.