Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Moderate or severe depression is now one of the most common diseases of our time with a prevalence of nearly 3%. It seems likely that this prevalence has increased as a result of the wider use of drugs which have an effect on the neurotransmitters. Changes in the levels of these neurotransmitters in the central nervous system are thought to be the biochemical basis for the development of at least some depressive illnesses. Drug-induced depressions are more likely to occur in those individuals who are genetically predisposed to depression or who have had a previous depressive illness. Other groups who are particularly susceptible to these effects are the elderly. Many groups of drugs have a primary or secondary action on the central nervous system neurotransmitter function. Some 200 drugs have been claimed to cause depression in certain patients, but only a relatively small number precipitate depressive symptoms with any frequency. Those most commonly implicated are the long-acting antipsychotics, barbiturates, ethanol, oral contraceptives and antihypertensive agents. It is important to remember that some drugs, such as reserpine, cause depression as a side-effect during their therapeutic use whereas others, such as fenfluramine, cause depression mainly when they are withdrawn too rapidly. In those patients presenting with depression, it is important to review the current drug therapy in order to assess the part played by these drugs in the development of the depression. Following this assessment, drug therapy should be adjusted appropriately. However, a distinction must be made between the symptoms of depression, those physiological changes which occur during treatment with a variety of drugs, and the patient's reaction to the disease for which they are being treated.
 ...
PMID:Drugs and depression. 2 37

Rats were maintained on ad lib food and a forced-intake regimen of ehtanol for up to 270 days. The ethanol treatment induced alterations in the metabolism of central catecholamines seen as increased endogenous concentrations of dopamine concomitantly with decreased concentrations of noradrenaline in the limbic forebrain. The synthesis of catecholamines, measured as the accumulation of dopa following inhibition of aromatic amino acid decarboxylase, was unchanged during chronic ethanol treatment. Local application of dopamine into the nucleus accumbens caused a greater increase in locomotor activity in chronic ethanol rats than in controls thus indicating that chronic ethanol treatment increased the sensitivity at or beyond central dopamine receptors. This phenomenon of functional dopamine receptor supersensitivity was first observed after 5 months of ethanol treatment and lasted for about 4 weeks after cessation of the ethanol treatment. The sensitivity of noradrenergic and cholinergic receptor mechanisms appeared to be unchanged after chronic exposure to ethanol. The effect of the GABAergic drug, gamma-butyrolactone (GBL) on the accumulation of dopa after inhibition of aromatic amino acid decarboxylase was studied in chronic ethanol rats. The enhancement of the dopa formation in dopaminergic neurons induced by GBL was markedly attenuated after chronic ethanol treatment. The gross behavioural depression by GBL was also weakened. This may indicate that chronic ethanol treatment causes subsensitivity of GABA receptors.
 ...
PMID:The effect of chronic ethanol administration on central neurotransmitter mechanisms. 4 85

Behavioral effects and blood or plasma levels of d-amphetamine, ethanol, cocaine, and diazepam were examined in rhesus monkeys treated chronically with alpha-l-acetylmethadol (LAAM), methadone, or vehicle. Chronic treatment with the opiates failed to alter blood or plasma levels and behavioral effects of d-amphetamine or ethanol. LAAM-maintained monkeys were somewhat less sensitive to rate-decreasing effects of cocaine on schedule-controlled responding, but cocaine plasma levels and half-lives generally did not differ across the chronic treatment conditions. Behavioral depression after diazepam was prolonged substantially in LAAM- and methadone-maintained monkeys, but blood levels of diazepam and metabolites were not increased prolonged in those animals. Naloxone partially antagonized the residual depression LAAM- and methadone-maintained monkeys 24 hr after diazepam, but had no effect on the weaker sesidual depression in vehicle-maintained aniamals. Thus, diazepam appeared to interfere with the metabolic inactivation of the opiates. One LAAM-maintained monkey showed recurrent episodes of LAAM overdose and eventually died during the course of the study.
 ...
PMID:Interactions of acetylmethadol or methadone with other drugs in rhesus monkeys. 10 65

Rats selectively bred for disparate degrees of ethanol-induced depression of spontaneous locomotor activity ('most affected' = MA; 'least affected' = LA) were trained on a swim task. Undrugged rats of the MA line swam significantly faster than rats of the LA line. Ethanol, 0.0--2.25 g/kg i.p., produced dose-dependent increases in swim time in rats of the 13 generation (F13). Averaged over trials, these increases were greater in LA than in MA rats and greater in males than in females, but there was no sex difference in peak impairment. Increases in swin time were uncorrelated with predrug performance. These findings were confirmed in younger F17 rats receiving 1.75 g EtOH/kg i.p. Although the lines differed in ethanol-induced impairment, F17 males of the two lines were not differentially impaired by pentobarbital (12.5--22.5 mg/kg, i.p.). The existence of task-dependent line differences in ethanol sensitivity emphasizes the nonunitary nature of ethanol-induced 'behavioral depression.'
 ...
PMID:Rats bred for ethanol sensitivity: impairment of swimming by ethanol and pentobarbital. 11 34

Several studies indicate that ethanol may depress the central nervous system by altering neurotransmitter release. Evidence obtained from the peripheral nervous system suggests that prostaglandins act as negative feedback inhibitors of transmitter release. If a similar process occurs in the brain, then perhaps ethanol affects transmitter release via a mechanism involving prostaglandins. Prostaglandin synthetase inhibitors were administered to adult HS/Ibg male mice prior to intraperitoneal injection of a hypnotic dose of either ethanol, propanol, or t-butanol. A significant decrease in the length of alcohol sleep time was found: in the ethanol study, this was coupled with a significant increase in waking blood alcohol levels. These results indicate that inhibition of prostaglandin synthesis alters CNS sensitivity to the depressant effects of alcohol. When the same inhibitors were administered prior to other sedative hypnotics, i.e., pentobarbital and chloral hydrate, no effect was found. This suggests that prostaglandins may be specifically involved in the biochemical mechanism of alcohol depression.
 ...
PMID:Prostaglandin synthetase inhibitors antagonize the depressant effects of ethanol. 11 88

The modifying effects of daily ethanol ingestion in the drinking water as a 15 % solution (v/v) on drug biotransformational changes induced by inhalation exposure to styrene (300 ppm or 1260 mg/m3, 6 h daily, 5 d/week, up to 17 weeks) were studied in rat liver and kidney. The drug hydroxylation activities (7-ethoxycoumarin O-deethylase and 2,5-diphenyloxazole hydroxylase) both in liver and in kidneys were increased more by ethanol ingestion than by styrene inhalation. When administered in combination, styrene and ethanol exerted mostly an additive enhancing effect. However, hepatic NADPH-cytochrome c reductase activity was reduced both in styrene and in ethanol-treated rats. Hepatic styrene oxide hydratase activity was virtually unaffected by styrene treatments. The depression of glutathione concentration in liver was greater after styrene-ethanol than after styrene treatment alone. The hepatic UDPglucuronosyltransferase activity was enhanced slightly both in styrene and in styrene-ethanol rats. The binding affinity of styrene towards cytochrome P-450 was increased after styrene inhalation as shown by lowered K8 values. The perirenal fat concentration of styrene showed a rough inverse relationship to the overall monooxygenation activities in liver and kidney. Despite the additively induced enzyme activities in styrene-ethanol-treated rats the accumulation of styrene in fat of these animals was on the whole somewhat greater, suggesting that these two solvents in vivo also have mutual inhibitory effects on biotransformation.
 ...
PMID:Effects of intermittent styrene inhalation, ethanol intake and their combination on drug biotransformation in rat liver and kidneys. 11 16

Drugs which increase brain levels of serotonin (5-HT) have frequently been found to cause a decrease in voluntary ethanol consumption. Results obtained with parachlorophenylalanine (pCPA), which decreases 5-HT, have been less consistent. The present investigation compared the effects of pCPA on alcohol selection with those of pargyline, a monoamine oxidase inhibitor which increases brain levels of 5-HT. Ingestion of a 10% ethanol solution was assessed in male C57BL/6J mice given daily injections of 250 or 300 mg/kg pCPA, 50 mg/kg pargyline, or saline. An additional control group received no treatment. A two-bottle preference procedure was employed, and ethanol and water intake were recorded during a pretreatment period (11 days), a treatment period (8 days), and a posttreatment period (10 days). Like other agents which increase 5-HT, parygyline produced a depression in ethanol intake which lasted beyond the time of drug administration. pCPa had no effect on ethanol ingestion either during the period of drug administration or afterwards.
 ...
PMID:Reduction of alcohol selection by pargyline in mice. 13 69

The understanding of the effects of cannabinoids in human subjects has been obscured by a lack of knowledge about how the various active principles from marijuana act at the cellular level in the brain. For this reason the present study was undertaken to determine the effects of cannabinoids on the enzymes associated with the synaptic membranes. Electron micrographic analysis was performed to determine the purity of synaptic membrane preparations from rat brain, and subsequently such preparations were subjected to additions of ethanol, Tween-80, 80% glycerol, and either delta-tetrahydrocannabinol, 11-hydroxy-delta-tetrahydrocannabinol, or cannabinol. Both sodium and potassium activated ATPase (Na, K-ATPase), and Mg-ATPase were measured as the micrometer orthophosphate (P) released per minute per microgram membrane protein and these specific activities of the enzymes expressed as absolute values and as the percentage depression brought about by the cannabinoids. The ATPase spcific activities are taken from the rate curve over a 30-min incubation time. Additionally, synaptic membrane acetylcholineesterase specific activity was measured by continuous rate enzyme assay. While as low as 10 M delta-tetrahydrocannabinol showed appreciable decrements in both the membrane-bound ATPases, the other cannabinoids did not show such a great depression in enzyme activity. The specific activity of acetylcholinesterase, which is weakly bound to the membrane, showed only slight or no changes in activity with the various cannabinoids. It was additionally shown that the cannabinoids, delta-tetrahydrocannabinol in particular, bound to the synaptic membranes almost irreversibly in the in vitro system, and that the vehicle for dissolving the cannabinoids, while used as background control values when calculating the percentage decrements in enzyme specific activity, did vary the effects on the ATPase enzymes in particular. These data are discussed in relation to psychotomimetic activity of the cannabinoids.
 ...
PMID:Effects of cannabinoids on synaptic membrane enzymes. I. In vitro studies on synaptic membranes isolated from rat brain. 14 40

Dr. Brown traces the history of America's federal mental health program from its beginning in the early 1900s. NIMH, the institute he currently directs, was established in 1946 for the treatment and prevention of mental and emotional illnesses through research,training, and services. It is now one of the institutes of the Alcohol, Drug Abuse, and Mental Health Administration of the Department of Health, Education, and Welfare. Dr. Brown describes its continuous progress toward providing high-quality mental health care to the entire population, and discusses priorities for the future that include continuation of research on schizophrenia and depression and research that will benefit children and the elderly.
 ...
PMID:The federal mental health program: past, present, and future. 17 35

The metabolism of 2-deoxy-D-galactose has been studied in AS-30D rat ascites hepatoma cells in suspension. Using 2-deoxy-D-(1-14C)galactose and an alkaline ethanol deproteinization procedure, the quantitatively identified metabolites included 2-deoxy-D-galactose 1-phosphate comprising 99.3%, and UDP-2-deoxy-D-galactose and UDP-2-deoxy-D-glucose, together amounting to 0.4% of the total metabolites. After incubation for 5 h in the presence of 2-deoxy-D-galactose (1 mmo1/1), the content of 2-deoxy-D-galactose 1-phosphate reached 35 mmo1x(kg cells)-1. The rate of phosphorylation of 2-deoxy-D-galactose was rapid during the first 30 min and decreased to approximately 20% of this rate during the subsequent hours. The rapid trapping of Pi in the form of 2-deoxy-D-galactose 1-phosphate resulted in a depression of free intracellular Pi in spite of a concomitant increase in net 32Pi uptake from the medium and a decrease of ATP and other 5'-nucleotides. The rates of glucose utilization and lactate production were depressed by more than 80% in the presence of 2-deoxy-D-galactose (1 mmo1/1). Interruption of Pi trapping by removal of 2-deoxy-D-galactose from the medium reversed the depressions of Pi and ATP and resulted in a rapid but incomplete relief of glycolysis inhibition. Crossover analysis of glycolytic intermediates indicated an inhibition at the 6-phosphofructokinase step. The depression of glucose utilization may be mediated by the increased level of glucose 6-phosphate, a potent inhibitor of hexokinase. An additional inhibitory effect of a metabolite of 2-deoxy-D-galactose at the 6-phosphofructokinase step was indicated by crossover analysis after reversal of Pi and ATP depressions in the presence of a high intracellular content of 2-deoxy-D-glactose 1-phosphate. The quantitative analysis of the metabolites of 2-deoxy-D-galactose demonstrated the predominance of the monophosphate and the negligible formation of UPD derivatives of this sugar analog in AS-30D hepatoma cells. This provides a system for the investigation of a galactose analog as a phosphate-trapping agent in the virtual absence of uridylate trapping.
 ...
PMID:2-Deoxy-D-galactose metabolism in ascites hepatoma cells results in phosphate trapping and glycolysis inhibition. 19 12


1 2 3 4 5 6 7 8 9 10 Next >>