ABSTRACT
Intraperitoneal injection 10 min before sacrifice of 1.5 g ethanol/kg weight produced an increase in rat striatal levels of homovanillic acid (HVA) (p < 0.05) but did not affect the striatal concentrations of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA). A similar ethanol treatment led to decreases in 5-HT (p < 0.05) and 5-HIAA (p < 0.05) from cerebral cortex (prefrontal and anterior cingulate areas). The results point to several ethanol-linked alterations in central serotonergic and dopaminergic systems.
Subject(s)
Cerebral Cortex/drug effects , Corpus Striatum/drug effects , Dopamine/metabolism , Ethanol/administration & dosage , Ethanol/pharmacology , Serotonin/metabolism , 3,4-Dihydroxyphenylacetic Acid/metabolism , Animals , Cerebral Cortex/metabolism , Corpus Striatum/metabolism , Homovanillic Acid/metabolism , Hydroxyindoleacetic Acid/metabolism , Male , Rats , Rats, WistarSubject(s)
Biogenic Monoamines/metabolism , Cerebral Cortex/drug effects , Corpus Striatum/drug effects , Ethanol/adverse effects , Substance Withdrawal Syndrome/drug therapy , Animals , Anti-Anxiety Agents/pharmacology , Cerebral Cortex/metabolism , Corpus Striatum/metabolism , Hydroxyindoleacetic Acid/metabolism , Hypnotics and Sedatives/pharmacology , Male , Midazolam/pharmacology , Rats , Rats, Wistar , Somatostatin/pharmacology , Substance Withdrawal Syndrome/metabolism , Thiopental/pharmacology , Time FactorsABSTRACT
Administration of ethanol for 40 days, at 10.53 +/- 0.25 g/kg/day did not modify levels of dopamine (DA) or 3,4-dihydroxyphenylacetic acid (DOPAC) in the striatum of the rat; however, the concentration of homovanillic acid (HVA) and the ratio of turnover were increased in a statistically significant way (P < 0.05). Twenty-four hours after withdrawal of ethanol appears as the central time of the ethanol-induced abstinence syndrome, showing noticeable decreases in levels of DA (P < 0.05) and DOPAC (P < 0.05), with respect to control and chronically ethanol-treated groups. The concentrations of DA, DOPAC and HVA and ratio of turnover values showed a tendency to return to control normal levels of 48 hr after ethanol withdrawal, although the differences still showed statistical significance (P < 0.05). The intraperitoneal injection of saline, the water soluble benzodiazepine midazolam, the barbiturate thiopental and somatostatin, in single doses, resulted in a noticeable increase in levels of DA, DOPAC and HVA and ratio of turnover values. The intraperitoneal injection of midazolam produced statistically significant decreases in levels of DOPAC and ratio of turnover values (P < 0.01) in rats 48 hr after withdrawal of ethanol, with respect to control and chronically ethanol-treated animals, in contrast to the absence of changes produced when injecting thiopental or somatostatin.
Subject(s)
3,4-Dihydroxyphenylacetic Acid/metabolism , Corpus Striatum/metabolism , Dopamine/metabolism , Ethanol/pharmacology , Homovanillic Acid/metabolism , Substance Withdrawal Syndrome/psychology , Animals , Barbiturates/pharmacology , Benzodiazepines/pharmacology , Chromatography, High Pressure Liquid , Corpus Striatum/drug effects , Male , Rats , Rats, Wistar , Somatostatin/pharmacologyABSTRACT
1. The effects of three dihydropyridine derivates were studied and compared with those of nifedipine in guinea-pig ileum. 2. Nifedipine, nimodipine, nitrendipine (25-200 nM) and nisoldipine (10-80 nM) produced a dose-dependent inhibition of the contractile responses induced by single pulse stimulation, acetylcholine (1 microM) and high-K (50 mM). 3. From these experiments it is concluded that nimodipine and nitrendipine, like nifedipine, produced a similar and potent inhibitory effect of the contractile responses induced in the guinea-pig ileum. 4. Nisoldipine resulted to be the most active agent.