Drugs online research references
Psychopharmacology (Berl). 1986;89(3):311-6.
Lithium and bupropion antagonise the phasic changes in locomotor activity caused by dopamine infused into the rat nucleus accumbens.
Barnes JC, Costall B, Domeney AM, Naylor RJ.
Dopamine infused persistently (25 micrograms/24 h for 13 days) into the nucleus accumbens of rat brain caused phasic increases in spontaneous locomotor activity during the period of infusion. This phasic responding was prevented by lithium administered throughout the infusion period in divided doses (3 X daily administrations of 2.5 mg/kg IP) or as a continuous IP infusion (7.5 mg/kg/24 h), and by bupropion treatment (5-20 mg/kg 3 X daily). In contrast, imipramine, amitriptyline and nomifensine failed to prevent the phasic locomotor response to dopamine at doses which did not by themselves cause marked motor changes. Locomotor activity was measured using individual photocell cages, and rats preselected to (-)NPA were those initially showing a modest locomotor activity. Fourteen to twenty-eight days after discontinuing the dopamine infusion rats showed increased responsiveness to (-)NPA which persisted throughout the remainder of the 70-day withdrawal period. This long-term change was prevented when lithium was given continuously throughout the period of dopamine infusion, but not when lithium was given in divided doses, showing the importance of the mode of drug delivery. The long-term change caused by the dopamine infusion could also be prevented by bupropion but not by imipramine, amitriptyline or nomifensine to show again that the actions of classical antidepressant drugs may be differentiated from those of lithium and bupropion. Therefore, it is suggested that the model of phasic hyperactivity described may provide a means for more closely analysing, both behaviourally and biochemically, the site and mechanism of action of lithium (and bupropion) in the control of the short- and long-term consequences of an enhanced mesolimbic dopamine activity.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3088656&dopt=Abstract
word match wellbutrin online literature
Biomed Chromatogr. 1997 May-Jun;11(3):174-9.
Enantiomeric determination of the phenylmorpholinol metabolite of bupropion in human plasma using coupled achiral-chiral liquid chromatography.
Suckow RF, Zhang MF, Cooper TB.
Analytical Psychopharmacology Division, New York State Psychiatric Institute, New York 10032, USA.
A coupled achiral-chiral stationary phase liquid chromatographic technique was developed to separate and quantitate the enantiomers of the phenylmorpholinol metabolite (2) of the antidepressant bupropion (1) in human plasma. At the retention time of 2, a switching valve loaded a portion of the eluting compound onto a protein-bonded chiral stationary phase which resolved 2 into the (+) and (-) stereoisomers using an aqueous mobile phase of potassium phosphate (pH = 6.25) and 5% 2-propanol. All eluting compounds were monitored using UV detection at 214 nm, and no plasma endogenous material or other commonly used psychotropic drugs were found to interfere. Within-day and between-day variation were less than 6% over the expected concentration range, and a limit of quantitation of about 125 ng/mL of 2 was observed. Steady-state plasma samples from 17 patients receiving 1 were found to contain the (-) enantiomer to the extent of about 96% of total 2. The potential clinical implications of these results are not known since all previous pharmacological studies were carried out with the racemic 2.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9192113&dopt=Abstract
word match wellbutrin online literature
Neuropsychopharmacology. 1989 Dec;2(4):273-9.
Acute effects of bupropion on extracellular dopamine concentrations in rat striatum and nucleus accumbens studied by in vivo microdialysis.
Nomikos GG, Damsma G, Wenkstern D, Fibiger HC.
Department of Psychiatry, University of British Columbia, Vancouver, Canada.
This study examined the acute effects of the novel antidepressant drug, bupropion, on extracellular concentrations of dopamine (DA), its metabolites, and the serotonin metabolite 5-HIAA in the striatum and nucleus accumbens using on-line microdialysis in freely moving rats. Bupropion HCl (10, 25, and 100 mg/kg intraperitoneally) increased extracellular striatal DA in a dose- and time-dependent manner; 1 mg/kg did not affect extracellular DA. The maximal response occurred within the first 20 minutes (+76%, +164%, and +443% for each dose, respectively) followed by a gradual decrease to a stable but elevated level for the next 2 hours. This neurochemical response was strongly associated with bupropion-induced stereotyped behavior during the first hour but not during the subsequent 2 hours. Bupropion decreased DOPAC concentrations, increased 5-HIAA, and had variable effects on homovanillic acid (HVA) (decreases with 10 mg/kg and increases with 25 and 100 mg/kg). The increase in extracellular DA after bupropion (25 mg/kg) was blocked by tetrodotoxin and was therefore action-potential-dependent. Bupropion produced similar neurochemical responses in the striatum and the nucleus accumbens. These results suggest that increases in DA transmission contribute to the behavioral effects of bupropion and are consistent with a role for DA in the antidepressant effects of this drug. The partial dissociation between DA release and stereotyped behavior suggests that the relationship between neurotransmitter release and behavior may be complex.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2482026&dopt=Abstract
word match wellbutrin online literature
Herbs and Pharmaceuticals Online ||
Hair Million herbal formula for hair loss and hair growth ||
Antibiotics and prescription medications online literature ||