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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The general activity of rats in an open field test situation was observed following the central administration of isotonic saline and 0.5 and 2.0 mug of noradrenaline into the locus coeruleus. A significant increase in activity was found following the 0.5 mug, but not the 2.0 mug dose. The results are consistent with other reports indicating that low doses of centrally administered noradrenaline produce behavioural arousal whereas higher doses may result in behavioural depression. In addition, these findings suggest that the noradrenergic neurons arising from the locus coeruleus may be important for the arousal status of rats.
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PMID:Dose-related effects of central noradrenaline stimulation on behavioural arousal in rats. 122 95

There was a depression of transformation of noradrenaline, DOPA and thyrosine added in vitro, into catecholamines in the adrenal glands of rats after swimming for a period of 8 hours. This permitted to suppose a depression of the activity of phenylethanolamine-N-methyl-transpherase, DOPA-decarboxylase, and, possibly, of tyrosine hydroxylase under these conditions. After the end of swimming, in the presence of 1-tyrosine, there is at first an activation of noradrenaline synthesis, and then there occurs a gradual normalization (on the 7th day) of adrenaline formation. In rats trained for a period of 2 months the extent of reduction of the catecholamine synthesis in the adrenal glands in response to the 8-hour swimming was much less in comparison with the untrained aniamals.
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PMID:[Mechanisms of catecholamine synthesis disorders in the adrenals of rats subjected to physical fatigue]. 122 89

By subcutaneous implantation of 2 or 13 morphine pellets (75 mg morphine/pellet), rats were made tolerant to, and dependent on narcotic analgesics. Occipital cortex slices from dependent animals and placebo-implanted controls were incubated with (-)-3H-noradrenaline and subsequently superfused with physiological salt solution. The accumulation of 3H-noradrenaline was not changed by pretreatment with 2, but was slightly decreased by pretreatment with 13 morphine pellets. The overflow of tritium evoked by electrical field stimulation was higher in slices from morphine-implanted rats than in those from placebo controls. Morphine and levorphanol, added in vitro, inhibited the stimulation-induced overflow of tritium at similar concentrations and to a similar degree in slices from morphineand placebo-pretreated animals.--It is concluded that, during chronic treatment with morphine, an adaptation takes place in the brain to compensate for the acute effect of narcotic analgesics, i.e. inhibition of the release of noradrenaline by nerve impulses. The chain of events from the drug-receptor interaction to the depression of the release process can be escluded as substrate of this adaptation. During withdrawal, the compensatory changes provoke an enhanced increase of extracellular noradrenaline during nerve impulses.
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PMID:Morphine tolerance and dependence in noradrenaline neurones of the rat cerebral cortex. 123 93

The functions of the central monoamines Norepinephrine (NE) and Serotonin (5HT) can be clarified by the study of behaviors of rats administered selective monoamine toxins. In his home environment the low NE rat has drive deficits and is lethargic, tending to remain in his burrow, but in novel environments this animal acts less frightened than Controls. The low 5HT rat is conversely active and exploratory in familiar environments but frightened in novel environments. These two animals model aspects of depression and anxiety, respectively. 5HT can be thought of as placing the brain into a state of consciousness appropriate for an animal in his nest (i.e., 5HT neurons act as relaxers), and as involved in a type of positive affect related to security, whereas NE neurons are dominant when an animal is vigilant, foraging out in the environment and are involved in a type of positive affect related to goal-directed approach arousal. Monoamine toxins may be produced when the behaviors elicited by these central neuronal systems are negatively reinforced (extinguished).
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PMID:Behavior and the balance between norepinephrine and serotonin. 123 10

The drug l-deprenyl has been reported to have antidepressant properties, and in the present study three possible mechanisms of action were investigated in animal experiments. l-Deprenyl, which is a type B monoamine oxidase (MAO) inhibitor, was compared to clorgyline, an MAO A inhibitor with regard to its inhibitory effect on the formation of three major catecholamine metabolites, homovanillic acid (HVA), dihydroxyphenylacetic acid (DOPAC) and 3-methoxy-4-hydroxyphenylglycol (MOPEG) in the rat brain in vivo. Apart from a difference in dose levels the two drugs showed no difference in the dose--response pattern of all three metabolites. Clorgyline inhibited the formation of HVA, DOPAC and MOPEG with an ED50 of about 0.2 mg/kg s.c. and l-deprenyldopamine and noradrenaline are formed by the same type of monoamine oxidase(s), probably type A, in the rat brain in vivo. Antidepressant properties of l-deprenyl therefore seem to be independent of catecholamine deamination. l-Deprenyl but not clorgyline (2 or 8 mg/kg s.c.) potentiated the stereotyped sniffing behaviour induced by beta-phenylethylamine, a specific substrate for type B monoamine oxidase. This result is discussed in relation to a new hypothesis of phenylethylamine and dopamine involvement in depression. l-Deprenyl was 10,000 times less potent than DMI as inhibitor of noradrenaline uptake in crude synaptosomes from the occipital cortex of rat brain. Inhibition of noradrenaline uptake was therefore excluded as a possible mechanism for the antidepressant action of l-deprenyl.
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PMID:The monoamine oxidase B inhibitor deprenyl potentiates phenylethylamine behaviour in rats without inhibition of catecholamine metabolite formation. 124 62

Noradrenaline and dopamine injected into the lateral brain ventricle exerted a significant effect on the behavior of rats. Both amines caused a slight rise in the basic locomotor activity which was significantly increased in the animals with inhibited monoamine oxidase activity. Besides that, they suppressed the behavior of rats in the open-field test, inhibited the conditioned avoidance response, decreased body temperature and increased amphetamine-induced motor hyperactivity. Noradrenaline, in contrast to dopamine, changed the intensity of amphetamine-induced stereotypy and prolonged the action of hypnotics. The central action of both catecholamines (in higher doses especially) seemed to have a biphasic course: in the first phase after administration depression was observed which was more pronounced after noradrenaline administration, in the second phase a stimulating effect b
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PMID:Comparison of central effects of noradrenaline and dopamine injected into the lateral brain ventricle in rats. 124 88

Various drugs have been applied electrophoretically to Renshaw cells and to unidentified spinal neurones in pentabarbitone anaesthetized or decerebrated rats. Responses to noradrenaline (NA) and 5-hydroxytryptamine (5-HT) have not previously been described at this site and were of two types; either monophasic depression or biphasic depression-excitation. The effect of harmine on these responses was examined. Harmine and harmaline were also tested on the excitant responses to acetylcholine (ACh) and DL-homocysteate (DLH), and on the depressant responses to glycine and gamma-aminobutyric acid (GABA). On some cells harmaline antagonized ACh, but not DLH, and glycine, but not GABA, responses. Harmine caused only non-specific depression and spike configuration changes. The effects of harmine on NA and 5-HT responses were usually non-specific, and any anatagonism was usually accompanied by, or soon followed by spike changes. LSD was also tested on the amine responses. LSD itself had a clear depressant effect on neuronal firing rates. It could either antagonize or potentiate NA and 5-HT depressant responses, but the antagonism in particular was closely followed by spike changes. Somewhat more specific antagonism of the late excitation was seen.
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PMID:The effects of beta-carbolines on responses to acetylcholine, noradrenaline, 5-hydroxytryptamine and amino acids in the rat spinal cord. 124 86

The acute administration of 4-chloroamphetamine caused a marked reduction in the concentration of serotonin and 5-hydroxyindoleacetic acid and a rise in dopamine in the rat brain. Following the injection of 3H-tyrosine and 3H-tryptophane into rats treated with 4-chloroamphetamine, there was a reduction in brain levels of 3H-dopamine and 3H-serotonin. Although the endogenous concentration of noradrenaline was not affected by 4-chloroamphetamine, there is evidence that its reuptake into neurones was reduced and its release increased by the drug. Following the administration of 4-chloroamphetamine for 10 days, the concentration of 5-hydroxyindoleacetic acid was reduced; no other changes in amine metabolism were apparent. From this investigation, and those of others, it appears that following acute administration, 4-chloroamphetamine has a neurochemical profile which has a similarity to that of many tricyclic antidepressants. However, there is a marked discrepancy between the acute and chronic effects of 4-CA on brain amine metabolism. Such findings are difficult to reconcile with the widely accepted theory that antidepressant drugs counteract the symptoms of depression by increasing the concentration of noradrenaline and/or serotonin at receptor sites within the brain.
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PMID:Acute and chronic effects of 4-chloroamphetamine on monoamine metabolism in the rat brain. 125 60

The potential importance of the endothelial system in regulating the effects of (-)-Bay K 8644 (0.1 microM), (+)-Bay K 8644 (0.1 microM) and nifedipine (10 nM) on resting tension, on contractile responses to noradrenaline (NA) and Ca2+ (in a Ca(2+)-free high-K+ solution), and on basal, NA-induced and K(+)-induced 45Ca2+ uptake, was investigated in rat aorta rings. Mechanical removal of endothelium considerably potentiated the contractile response induced by NA in standard medium and by Ca2+ in Ca(2+)-free high-K+ (15 mM) medium, but did not modify the response induced by Ca2+ in Ca(2+)-free high-K+ (55 mM) medium or by NA in Ca(2+)-free medium. Furthermore, the basal 45Ca2+ uptake and that induced by NA (10 microM) or KCl (15 and 55 mM) were similar in endothelium-rubbed and intact rings. (-)-Bay K 8644 (0.1 microM) shifted the NA and Ca2+ concentration-response curves to the left with potentiation of the maximal contraction. However, (+)-Bay K 8644 (0.1 microM) and nifedipine (10 nM) caused a shift to the right, with depression of the maximal contraction. The NA concentration-response curves, and those of Ca2+ in Ca(2+)-free high-K+ (55 mM) medium, were affected by the drugs to similar extents, and were not modified by the presence or absence of endothelial cells. The drugs tested did not affect resting tension. Basal 45Ca2+ uptake was not modified by either nifedipine or the Bay K 8644 enantiomers.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Role of the endothelial system in Bay K 8644 enantiomer and nifedipine vasomodulator action in rat aorta. 128 Nov 5

Panic episodes were described as a distinct form of anxiety by Freud almost 100 years ago, and the recent publication of the Diagnostic and Statistical Manual of Mental Disorders, third edition (D.S.M.-III), has provided the basis for the separate diagnostic entity of panic disorder. In this study, we showed the historical review of research and the result of our clinical study of panic disorder in 7 patients. The following results were obtained: 1) Abnormal DSTs were observed in only two of 5 patients. 2) Five of 6 patients showed high concentration of adrenaline and noradrenaline in urine. 3) Anxiety was provoked by caffeine in two of 5 patients. 4) Depression of T-wave was shown in three of 5 patients with orthostatic E.C.G. 5) Sinus tachycardia was gained in one of 3 patients with Holter E.C.G. 6) Abnormal respiratory functions were observed in all two patients with Treadmill. 7) Only one small heart was observed on a chest radiograph. 8) Panic attacks were provoked by sodium lactate infusion in four of 7 patients.
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PMID:[Panic disorder]. 128 52


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