Behavioral effects of a new dopamine-beta-hydroxylase inhibitor (fusaric acid) in man

Pyridine alkaloids with activity in the central nervous system

This review discusses all pyridine alkaloids with CNS activity, their therapeutic potential, and the interesting array of sources whence they originate.

Fusaricates H-K and fusolanones A-B from a mangrove endophytic fungus Fusarium solani HDN15-410

Seven compounds including four undescribed fusaric acid derivatives, namely fusaricates H-K, and two undescribed γ-pyrone derivatives, named fusolanones A-B, as well as a known compound fusaric acid, were isolated from a mangrove endophytic fungus Fusarium solani. Fusaricates H-K represent the first cases of fusaric acid butanediol esters and are diastereoisomers. Their structures including absolute configurations were elucidated based on NMR, MS, chemical synthesis, chiral HPLC analysis and ECD calculations. The antibacterial activity of all undescribed compounds were tested and fusolanone B showed the best activity with MIC value 6.25 μg/mL on Vibrio parahaemolyticus.

New Fusaric Acid Derivatives from the Endophytic Fungus Fusarium oxysporum and Their Phytotoxicity to Barley Leaves

Chemical investigation of the endophytic fungus Fusarium oxysporum isolated from fruits of Drepanocarpus lunatus afforded eight new fusaric acid derivatives, fusaricates A-G, 1-7, and 10-hydroxy-11-chlorofusaric acid, 8, along with four known compounds. Their structures were elucidated by one- and two-dimensional NMR as well as MS data and by comparison with the literature. The absolute configurations of fusaricates C-E, 3-5, were determined using chiral GC-MS. Fusaricates A-G, 1-7, represent the first examples of fusaric acid linked to a polyalcohol moiety via an ester bond. All isolated fusaric acid derivatives 1-8 showed significant phytotoxicity to leaves of barley.

Clonidine-induced growth hormone secretion in chronic schizophrenia

Clonidine (0.15 mg intravenously), an alpha-adrenergic receptor agonist, was administered to 13 male chronic schizophrenics, who had been withdrawn from chronic neuroleptic therapy, and to 18 normal male controls. There was no significant difference in growth hormone (GH) response between the two groups. There was no significant correlation between duration of psychosis, duration of neuroleptic therapy or length of neuroleptic withdrawal and GH response. These results suggest that postsynaptic alpha-adrenergic receptor function in the hypothalamic-pituitary axis is unaltered in chronic schizophrenia or by prior chronic neuroleptic therapy.

Dopamine-beta-hydroxylase and its apparent endogenous inhibitory activity in the plasma of some psychiatric patients

The "apparent" and "absolute" levels of dopamine-beta-hydroxylase (DBH) in 62 psychiatric patients and 20 healthy control subjects have been investigated. No significant differences could be detected between control subjects and patients diagnosed as schizophrenic, unipolar depressive and bipolar depressive, when DBH was assayed in the presence of the anti-inhibitors Cu++ and N-ethylmaleimide (i.e., "absolute" DBH activity). In the absence of these anti-inhibitors, however, the levels of plasma DBH (i.e., "apparent" DBH activity) were considerably reduced in all cases, with the schizophrenic group also being significantly reduced (p less than 0.02) in comparison with the control group.

Perspectives in the treatment of the psychoneurological disorders: affective disorders

1. Current research strategies in the pharmacotherapy of the affective disorders are reviewed in an attempt to highlight major trends and areas of particular promise. 2. There has been some progress toward the identification of biologically defined subgroups by assessing amine metabolites in urine or cerebrospinal fluid which may lead to a more rational choice of therapies for depressed patients. 3. The use of drugs with receptor agonist properties may help define biological substrates altered in affective illness and lead to new approaches to treatment, such as utilization of low doses of receptor agonists which may preferentially stimulate presynaptic receptors. 4. Study of time-dependent and adaptive changes in receptor sensitivity may also add an important perspective in conceptualizing the cyclic process in manic-depressive illness and its treatment.

Treatment of schizophrenia

1. Progress in 25 years' history of the neuroleptics is briefly reviewed. 2. Development of certain butyrophenones more directly effective in "minus" symptoms of schizophrenia and introduction of depot neuroleptics is discussed. 3. Extrapyramidal motor side effects (EPMS) are still a serious problem in the treatment. 4. Clozapine does not have EPMS. This drug could therefore become the starting point of a series of less hazardous antipsychotic drugs. 5. The neuroleptics can be used as tools for exploration of the etiopathogenesis of schizophrenia. Some important pharmacological mechanisms, i.e. their antidopaminergic activity, are briefly outlined.

Norepinephrine-dopamine interactions and behavior

The proposed hypothesis is directed toward explaining a number of disparate findings in terms of a stress-related interaction between the NE- and DA-containing systems in the brain. The deleterious behavioral effects of decreased DA activity, for example, may be counterbalanced by a similar decrease occurring in NE activity, such compensation being most likely to occur under conditions of stress. This hypothesis may have application to the understanding of neurological and mental disorders such as Parkinson's disease and schizophrenia.