BACKGROUND The anxiety-reducing effect of long-term administration of serotonin reuptake inhibitors is usually seen only in subjects with anxiety disorders, and such patients are also abnormally inclined to experience a paradoxical anxiety-enhancing effect of acute serotonin reuptake inhibition. These unique responses to serotonin reuptake inhibitors in anxiety-prone subjects suggest, as do gen...

The rate of release of deuterons into the body water from 2,3,4,5,6-pentadeutero-L-phenylalanine has been shown to be a valid measure of the activity of the phenylalanine hydroxylase system in vivo. At a dose of 0.5 g/kg, the rate of release of deuterons is linear for 60 to 90 min. Male rats, which had previously been shown to have 22 to 25% more phenylalanine hydroxylase activity in liver extr...

1. Injection of L-tryptophan (750 mg/kg body wt.) led to pronounced hypoglycaemia in fed and 48 h-starved rats. 2. The hypoglycaemic effect is blocked by pretreament with p-chlorophenylalanine, compound MK-486 [Carbidopa: L-alpha-(3,4-dihydroxybenzyl)-alpha-hydrazinopropionic acid monohydrate] or methysergide, and potentiated by pargyline. 3. 5-Hydroxy-L-tryptophan is more potent and induces a ...

Verhofstad et al. (Verhofstad, A. A. J., H. W. M. Steinbusch, B. Penke J. Varga, and H. W. J. Joosten (1981) Brain Res. 212: 39-49) have reported that serotonin of the rat superior cervical ganglion is contained in a distinct and separate population of small intensely fluorescent (SIF) cells. We provide evidence that the serotonin-containing SIF cells are modulated, in part, by preganglionic ch...

Here we investigated the effects of electroacupuncture over the cognitive deficits in the pilocarpine model of epilepsy in rats. Acupuncture stimulation was provided at acupoints located in either the midline of the back and of the head [HD]: Gv-20 (Baihui), Gv-14 (Dazhui), Gv-2 (Yaoshu) and M-HN-3 (Yin Tang); or acupoints located in the limbs [LB]: St-36 (Zusanli) and Sp-6 (Sanyinjiao). In the...

The effect of tramadol on the plasma glucose level of streptozotocin (STZ)-induced diabetic rats was investigated. A dose-dependent lowering of plasma glucose was seen in the fasting STZ-induced diabetic rats 30 min after intravenous injection of tramadol. This effect of tramadol was abolished by pretreatment with naloxone or naloxonazine at doses sufficient to block opioid mu-receptors. Howeve...

Trichilia catigua is a native plant of Brazil; its barks are used by some local pharmaceutical companies to prepare tonic drinks, such as Catuama. The present study was addressed to evaluate the effects of T. catigua hydroalcoholic extract in mouse nociception behavioral models, and to evaluate the possible mechanisms involved in its actions. Male Swiss mice were submitted to hot-plate, writhin...

Acetaminophen (APAP) overdose is a major cause of acute liver failure. Peripheral 5-hydroxytryptamine (serotonin, 5-HT) is a cytoprotective neurotransmitter which is also involved in the hepatic physiological and pathological process. This study seeks to investigate the mechanisms involved in APAP-induced hepatotoxicity, as well as the role of 5-HT in the liver's response to APAP toxicity. We i...

BACKGROUND The aim of present study was to evaluate antidepressant-like activity of ellagic acid in Swiss young male albino mice; and to explore the possible underlying mechanisms for this activity. METHODS Mice were immobilized for 150 min once only for induction of stress. Ellagic acid (8.75, 17.5, 35 mg/kg, po) and fluoxetine (20 mg/kg, ip) per se were administered to unstressed and stress...