Nedathur Narasimhachari

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This study provides the first evidence for catecholamine synthesis and release in the RAW264.7 cell line, an important macrophage model. Although catecholamines were low in unstimulated cells, activation with lipopolysaccharide (LPS) induced tyrosine hydroxylase (TH) mRNA and increased extracellular norepinephrine and intracellular dopamine within 48 h. The(More)
Electrical stimulation of serotonergic neurons in the raphe nuclei of the midbrain or medulla enhances the formation of serotonin in vivo in the terminal projections of these neurons [I]. The acceleration of serotonin synthesis results from an increase in the conversion of tryptophan to 5-hydroxytryptophan (5-HTP) by tryptophan hydroxylase [2,3] [EC(More)
Cultured murine bone marrow derived mast cells (BMMC) were found to store high levels of dopamine (3753+/-844 pg/10(7) cells) and occasionally produce norepinephrine and epinephrine. The catecholamine synthesis inhibitor, alpha-methyl-para-tyrosine, decreased intracellular catecholamine concentrations, and activation with ionomycin stimulated dopamine(More)
Dextroamphetamine 30 mg and placebo were administered by mouth in a double-blind randomized cross-over trial to ten subjects. Behavior was assessed and blood samples analyzed for growth hormone (GH), prolactin (PRL), homovanillic acid (HVA), and amphetamine. There was a statistically significant increase in well-being following d-amphetamine as compared to(More)
Saliva drug concentrations are a function of the saliva flow rate at which they are collected. Increased saliva flow rate tends to restore the salivary concentration towards the free unbound plasma concentration of drug. For those drugs excluded from the saliva relative to their free plasma concentration, stimulation increases the observed drug levels in(More)
Electrical stimulation of the rat midbrain dorsal raphe nucleus, which contains clusters of 5-HT containing cell bodies, increased the activity of tryptophan hydroxylase prepared in low speed supernatant extracts from cerebral cortex, a region containing 5-HT projections arising from the dorsal raphe nucleus. In contrast, activity of enzyme from(More)
The level of INMT activity was determined in the sera of 29 psychiatric patients and 11 healthy controls from St. Louis; and in 13 psychiatric patients and 15 healthy controls from Chicago. The level of enzyme activity in the serum of paranoid schizophrenics in the St. Louis group was significantly higher than in other types of schizophrenics. The mean(More)
The effect of the α-noradrenergic receptor agonist, clonidine, on food intake and weight was examined in ten adult Stumptail macaque monkeys. An intramuscular injection of 0.1 mg/kg of clonidine HCl for seven consecutive days significantly increased food intake from baseline levels throughout treatment. All but two monkeys gained weight during clonidine(More)
Liquid chromatography with electrochemical detection (LC/ECD) and gas chromatography/mass spectrometry (GC/MS) were used to identify metabolites of N-methyl-3,4-methylenedioxyamphetamine (MDMA) in samples of rat plasma and urine. Several potential metabolites, based on what is known about the metabolism of the desmethyl analog (i.e., MDA), were synthesized(More)
Keeping biochemical determinations and clinical judgements independent, the authors investigated three aspects of the transmethylation hypothesis. They found that 26 acutely schizophrenic patients were no more likely to have bufotenine or N,N-dimethyltryptamine present in urine or elevated serum indolethylamine N-methyltransferase activity than 10 normal(More)