Effect of the NMDA-receptor antagonist dextromethorphan in infant rat pneumococcal meningitis.

Excitatory amino acids (EAA) and particularly glutamate toxicity have been implicated in the pathogenesis of neuronal injury occurring in bacterial meningitis by activating the N-methyl-d aspartate (NMDA) receptor complex. Here, we evaluated the effect of adjuvant treatment with the antitussive drug dextromethorphan (DM), a non-competitive NMDA receptor antagonist with neuroprotective potential, in an infant rat model of pneumococcal meningitis. The experiments were carried out in postnatal day 6 (P6) and 11 (P11) animals.

Relationships between brain concentrations of desipramine and paradoxical sleep inhibition in the rat.

Desipramine (DMI), like many antidepressant drugs, inhibit the production of paradoxical sleep (PS). In the present experiment, we have investigated the relationships between brain level of DMI and PS inhibition. Groups of rats had their sleep monitored after 1, 2 or 4 mg/kg of DMI.

Relationship between plasma-levels of chlorpromazine and effects on EEG and evoked potentials in healthy volunteers.

The effect of chlorpromazine (CPZ) was studied at four different doses in a group of 10 normal subjects. Blood levels of CPZ were assayed by gas chromatography and showed wide interindividual variations. Spontaneous brain electrical activity (EEG) was recorded from 8 leads and submitted to spectral analysis.

Effect of calcitonin on free and total plasma tryptophan in human.

The injection of calcitonin (0.5 or 1 microgram/Kg wt.) did not affect free and total tryptophan plasma levels in six healthy human subjects.

Distribution of tryptophan in erythrocytes, leukocytes and thrombocytes, and its binding to plasma albumin.

The extended theory about a dysfunction of the serotoninergic system in depression and schizophrenia includes the hypothesis of a disturbance in the transport systems of tryptophan and tyrosine from blood to brain. It would be interesting to know if blood cells may be used as a model for the central transport mechanisms of these amino acids. After an oral load, the in vivo distribution of L-tryptophan (50 mg/kg) was studied in the blood plasma, in the different blood cells and its binding to plasma albumin, in six healthy, seven schizophrenic and two depressive subjects.

The analysis of free tryptophan in human blood with the Ultrafiltrator: a comparison with other methods.

Recently, the Ultrafiltrator has been described, in the literature, which allows the ultrafiltration of small molecules in minute blood samples under anaerobic conditions with filters of any pore size. This apparatus has been tested for the separation of free tryptophan in heparinised and EDTA-plasma and in whole blood. At the same time, free tryptophan has been analysed after ultrafiltration with CF-50 A and CF-25 membrane cones (Centriflo).

[Seasonal rhythm of free tryptophan and nonesterified fatty acids in the blood of healthy subjects (author's transl)].

During one year, free and total tryptophan, tyrosine and non-esterified fatty acids were determined in the blood of eight healthy volunteers. No clear seasonal rhythm appeared for any of these parameters. But over this period, the following significant correlations were found: total tryptophan-free tryptophan; total tryptophan-tyrosine; free tryptophan-tyrosine.