Ovarian serotonin content in relation to ovulation

Summary In the mature cyclic female rat, analysis for ovarian serotonin content reveals comparatively high serotonin content. Fluctuation of serotonin content was observed; peak for serotonin was observed at estrus. In gonadotropintreated immature rats, there was no detected ovarian serotonin using this procedure. It was concluded that ovaries from gonadotropin-treated immature rats are physiologically different from ovaries taken from mature cyclic rats.Supported by NIH Grant RR8111.National Institutes of Health, MBS Trainee.     

A biphasic effect of estradiol on serotonin metabolism in rat pineal organ cultures

Summary Physiological amounts of estradiol (1 nM) significantly increased serotonin, conversion to melatonin and 5-methoxytryptophol by rat pineal glands in organ culture whereas larger, pharmacological, doses (i.e. 1000 nM) impaired it significantly. The stimulatory but not the inhibitory effect of estradiol was blocked by the simultaneous addition of puromycin in the culture medium.This study was supported by grant No. 6638 from the Consejo Nacional de Investigaciones Cientificas y Técnicas (CONICET), Argentina.     

Pathways of sugar metabolism in relation to the biosynthesis of polyacetylenic antibiotics

Zusammenfassung Der Einbau von [1-¹⁴C]-Acetat bei der Biosynthese von Xylose aus Äthanol durch die Basidiomycete B-841 beweist das Vorhandensein von drei verschiedenen Wegen des Zuckerstoffwechsels in diesem Pilz: 1. Glycolyse, 2. Transaldolase-Transketolase-Zyklus, 3. Abbau von Glucose zu Glucuronat und Pentose.     

Variability of the bohr effect in man

Riassunto L'effetto Bohr è notevolmente e significativamente più elevato nei diabetici che negli individui normali. Si dimostra che tale differenza non è dovuta ad un cambiamento nella molecola dell'emoglobina, ma alla presenza di un cofattore diverso da quelli noti e cioé dai fosfati organici ATP e 2–3 DPG.     

Corticosteroidogenesis by isolated human adrenal cells: effect of serotonin and serotonin antagonists.

The direct effect of serotonin and antiserotonin agents on adrenal steroid biosynthesis was studied in isolated adrenal cells derived from patients with Cushing's syndrome. The results indicate that serotonin increases corticosterone production, while the serotonin antagonists cyproheptadine and methysergide depress adrenal steroid - particularly cortisol and aldosterone - biosynthesis.     

The influence of inhibitors of amine metabolism on the effects of serotonin and its metabolites on photic evoked potential in rabbits

Resumen El estudio de la curva dosis-respuesta demuestra que el 5-hidroxi-triptofol y el acido 5-hidroxi-indolacético son tan potentes como la serotonina en modificar las respuestas corticales ópticas en el conejo. Pretratamiento con pargilina o con disulfiram, dos inhibidores distintos del metabolismo de las neuroaminas, influenció marcadamente los efectos de la serotonina sin cambiar los efectos de sus metabolitos.     

Hypnotic effect of serotonin administered in the vago-aortic afferent pathway

A minute amount of serotonin injected in the nodose ganglion circulation area develops abrupt myosis and general electrocortical synchronization activity in "encéphale isolé" Cat preparation. This hypnogenic effect of serotonin can still be reproduced after transection of vago-aortic nerves caudally to the nodose ganglia. The same injections become ineffective after rostral transection of the same pathway. These results suggest that serotonin may trigger some signs of sleep through peripheric nervous elements in which are probably localized in the nodose ganglia.     

Suppression of the immune response by drugs interfering with the metabolism of serotonin

Summary The work was based on the assumption that neurohumoral control of the immune response, particularly in stressed animals, involves central serotoninergic mechanisms. Rats immunized with sheep erythrocytes were stressed by repeated restraints and/or treated with a precursor of serotonin (5-hydroxytryptophan, 5-HTP) or with an inhibitor of serotonin synthesis (parachlorophenylalanine, PCPA). As expected, repeated stresses reduced the plaque-forming cell (PFC) response. Treatment with 5-HTP also reduced the PFC response, and potentiated the immunosuppressive effect of stress. This was accompanied by increased metabolism of serotonin in the brain, as indicated by increased concentration of its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), in cerebral tissue. Treatment with PCPA also suppressed the PFC response, but this suppression was accompanied by decreased levels of brain serotonin and of 5-HIAA. Plasma corticosterone levels were elevated in rats treated with PCPA. It seems that putative central effects of PCPA on serotoninergic regulation of the immune response were outweighed by its effects on corticosterone secretion and/or on lymphoid cells.     

Pharmacological effects of carbaryl II. Modification of serotonin metabolism in the rat brain

Zusammenfassung Nachweis, dass Carbaryl die Konzentration von Serotonin und 5-Hydroxyindolessigsäure im Rattenhirn steigert. Der Zusammenhang mit einem Stress wird als möglich angenommen.     

Suppression of the immune response by drugs interfering with the metabolism of serotonin

The work was based on the assumption that neurohumoral control of the immune response, particularly in stressed animals, involves central serotoninergic mechanisms. Rats immunized with sheep erythrocytes were stressed by repeated restraints and/or treated with a precursor of serotonin (5-hydroxytryptophan, 5-HTP) or with an inhibitor of serotonin synthesis (parachlorophenylalanine, PCPA). As expected, repeated stresses reduced the plaque-forming cell (PFC) response. Treatment with 5-HTP also reduced the PFC response, and potentiated the immunosuppressive effect of stress. This was accompanied by increased metabolism of serotonin in the brain, as indicated by increased concentration of its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), in cerebral tissue. Treatment with PCPA also suppressed the PFC response, but this suppression was accompanied by decreased levels of brain serotonin and of 5-HIAA. Plasma corticosterone levels were elevated in rats treated with PCPA. It seems that putative central effects of PCPA on serotoninergic regulation of the immune response were outweighed by its effects on corticosterone secretion and/or on lymphoid cells.