The Level and Diurnal Rhythm of Serum Serotonin in Manic-Deppessive Patients

Abstract

Although the etiology of manic-depressive psychosis is still obscure, its genetic study and the efficacy of somatic treatments such as electroconvulsive shock and psychotropic medication in manic-depressive psychosis would seem to suggest that depression might have a somatic causes). Imipramine type drugs and monoamine oxidase inhibitors (MAOI) affect brain monoamines-catecholamines and 5-hydroxytryptamine (serotonin)-, and the monoamine metabolism has come to be regarded by many workers to have an essential importance in affective disturbances6J8.31). Jensen") and others*) reported that reserpine reduced monoamines in the brain, and that about 15% of hypertensive patients treated with reserpine for long periods of time developed severe depression.Strom-Olsen and weil-Malherbe34) and Shinfuku et al.30) have found higher urinary excretion of norepinephrine in the manic than the retarded depressed phase of the disease. Based on those findings Schildkraut26.27) proposed the catecholamine hypothesis of affective disorders. The hypothesis is as follows: depressions are associated with an absolute or relative decrease in catecholamines, particularly norepinephrine, available at central adrenergic receptor sites.On the other hand Twarog and Page36) and Woolley and Shaw") gave an attention to the role of serotonin in the central nervous system. Brodie et al.5) emphasized that the tranquilizing action of reserpine is associated with variations in brain serotonin level and not in brain norepinephrine level. Coppen et al.7) found that the urinary excretion of tryptamine in depressive patients was about half of normal and that it returned to normal on clinical recovery. Ashcroft et a1.2) and Dencker et al.11) found that the cerebrospinal fluid in depressive patients contained reduced amounts of 5-hydroxyindolacetic acid (SHIAA), a metabolite of serotonin. Stevens et al.33) demonstrated the presence of a positive correlation between mood and urinary excretion of 5HIAA. However, the amount of urinary 5HIAA is markedly influenced by water and alcohol intakelo.2*). On the metabolism of serotonin in vivo, Hosodal6) reported that, in addition to the pathway to SHIAA, there exist several different metabolic pathways of serotonin leading either to serotonin-o-glucuronite, or 5-hydroxytryptophole etc. Therefore, it is more reliable to determine serum serotonin than the urinary excretion of 5HIAA. No report has been published on the serum serotonin level in manic-depressive

L-5-HTP Treatment and Serum 5-HT Level after L-5-HTP Loading on Depressed Patients

“…Therefore, it seemed to be of consider able practical significance to determineblood 5-HT level for the purpose of investigation into metabolic disturbance of 5-HT in psychotic disorders. As to the blood 5-HT level in de pressed patients, it is generally accepted that the level is reduced during depression, but returns to normal after clinical recovery (Sarai and Kayano, 1968;Coppen et al, 1976). Our findings of reduced serum 5-HT level in de pressed patients before ¿-5-HTP treatment is similar to previous observations.…”

“…One (Sarai and Kayano, 1968) claiming that the level was elevated, while another ( Takahashi, 1976) re porting that the level was reduced. In our studies Kaneko, 1975) including tire present data, there was consider able individual difference in untreated patients but definite findings have not been obtained.…”

Diurnal and seasonal variations in human platelet serotonin in man

“…In a larger group of both men and women, significant differences between 8 a.m. and 4 p.m. 5-HT were found in both sexes (Table 1). Although women tended to have higher values, the difference was not significant which has been previously observed (Genefke and Mandet, 1968;Sarai and Kayano, 1968)--c.f. platelet monoamineoxidase activity, where women have higher values than men (Wirz-Justice et at., 1975).…”

“…Earlier studies of the diurnal rhythm of 5-HT are conflicting. Higher evening values of serum 5-HT were found in two studies (Sarai and Kayano, 1968;Fogari and Corradi, 1974). In another (Genefke and Mandet, 1968), a diurnal rhythm in free but not in platelet 5-HT was observed.…”

Seasonal incidence of an altered diurnal rhythm of platelet serotonin in unipolar depression

“…During this time a certain number of untreated unipolar depressives were also investigated. In contrast to other studies (Sarai and Kayano, 1968;Coppen et al, 1976;Takahashi, 1976), no difference in platelet 5-HT between controls and unipolar depressives was found. This may have been due to the large variability between individuals, requiring a greater number of subjects than we investigated to establish statistically significant differences, or alternatively, that seasonal fluctuations influenced those studies where differences were found.…”