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

The effect of manipulation of GABA mechanisms in the region of the nucleus accumbens on dopamine-dependent locomotor hyperactivity in the rat has been studied. Two models of hyperactivity were used: (1) the injection of dopamine into the region of the nucleus accumbens in nialamide-pretreated animals and (2) the systemic administration of d-amphetamine. Both GABA and the GABA agonist 3-aminopropane sulphonic acid (3-APS) depressed hyperactivity in a dose-related manner. High concentrations of GABA (greater than 100 micrograms) were required to produce a significant effect and the response was short-lived possibly reflecting the efficient GABA inactivating mechanisms. 3-APS proved to be approximately 10 times more potent as compared to GABA in the dopamine-accumbens hyperactivity model. Conversely GABA receptor antagonism with low doses of either picrotoxin or bicuculline enhanced the mild locomotor response induced by a low dose of dopamine injected into the nucleus accumbens. However such results were difficult to evaluate fairly as higher doses of the GABA antagonists resulted in varying degrees of generalized seizures. Blockade of GABA uptake systems with cis-1, 3-aminocyclohexane carboxylic acid (ACHC), nipecotic acid or beta-alanine within the region of the nucleus accumbens produced dose-related depression of dopamine-dependent hyperactivity in both models. GABA uptake blockade (nipecotic acid) significantly enhanced the GABA-mediated depression of hyperactivity induced by bilateral injection of dopamine into the nucleus accumbens. The results demonstrate an inhibitory action of GABA and drugs facilitating GABA-ergic transmission on dopamine-dependent hyperactivity in the rat. Although open to criticisms of not being able to distinguish between true GABA effects and the results of non-specific neuronal depression the hyperactivity model underlines the potency of the GABA uptake blocking compounds and their possible potential for future clinical use.
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PMID:Dopamine-dependent hyperactivity in the rat following manipulation of GABA mechanisms in the region of the nucleus accumbens. 11 17

The possible involvement of substance P (SP) in cholinergic contractions induced by GABAA agonists in the guinea-pig ileum was further investigated. Responses evoked by 3-aminopropane sulphonic acid (3-APS) or muscimol consisted of a rapid phasic contraction followed in 70% of preparations by a tonic contraction, usually smaller in amplitude but considerably longer in duration. Phasic and tonic components were sensitive to bicuculline, neurogenic (cholinergic) in nature and susceptible to desensitization. Capsaicin (0.2 microM) pretreatment and SP receptor desensitization caused by 3 different priming SP concentrations (10 nM, 30 nM, 100 nM), depressed both components of the 3-APS-induced response, the magnitude of antagonism being greater for tonic contractions. Similar findings were obtained by using 10 microM (D-Pro4,D-Trp7.9)SP-(4-11), even though the degree of antagonism caused by this SP antagonist was consistently lower. These results indicate that depression of SP receptor function achieved by three different procedures decreases cholinergic contractile responses to GABAA agonists in the guinea-pig ileum. This provides further support for the hypothesis that GABAA receptor activation evokes both direct and indirect stimulation of enteric cholinergic neurons and that SP and/or a related peptide play an important role in mediating the indirect component of the cholinergic response.
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PMID:Involvement of substance P in the excitatory action of GABAA agonists on cholinergic neurons in the guinea-pig ileum. 244 28

1. The effects of gamma-aminobutyric acid (GABA), 3-aminopropane sulphonic acid (3-APS) and baclofen on spontaneous, electrically-induced and propulsive motility were investigated in rabbit distal colon. 2. In unstimulated longitudinal (LMPs) and circular muscle strip preparations (CMPs) 3-APS (10-200 microM) and GABA caused a clear-cut relaxation susceptible to desensitization. Baclofen (10-200 microM) caused relaxation in a minority (30%) of preparations. The 3-APS response was sensitive to tetrodotoxin (TTX; 1 microM), SR 95531 (a novel competitive GABAA-receptor antagonist) (10 microM), picrotoxinin (30 microM), and insensitive to hyoscine (1 microM) and to a combination of prazosin (1 microM) and propranolol (1 microM). The baclofen response was antagonized by 5-aminovaleric acid (DAVA, 500 microM), TTX and hyoscine and resistant to GABAA-receptor and adrenoceptor blockade. GABAA-receptors were therefore associated with non-adrenergic non-cholinergic (NANC) inhibitory nerve activation while GABAB-receptors were involved in depression of cholinergic tone of smooth muscle. GABA (10-200 microM) elicited both above mentioned effects. 3. In LMPs, baclofen (10-200 microM) dose-dependently inhibited submaximal responses to both cholinergic and NANC inhibitory nerve stimulation. This effect was resistant to SR 95531 and picrotoxinin and prevented by DAVA and baclofen desensitization. GABA (10-200 microM) mimicked the action of baclofen. GABA inhibitory effects persisted in the presence of GABAA-receptor blockade. 4. In segments of distal colon, GABA and baclofen (1-200 microM), but not 3-APS (1-200 microM), dose-dependently decreased the velocity of propulsion of an intraluminally-distended balloon. This effect was antagonized by DAVA and GABA or baclofen desensitization and resistant to SR 95531 and picrotoxinin. These antagonists per se had no effect on propulsion. In preparations in which propulsion was slowed by hyoscine (1 microM), baclofen caused no consistent further depression of propulsive activity. 5. Our results show that GABAA- and GABAB-receptors are present in rabbit colon. GABAA-receptor stimulation activates NANC inhibitory nerves without apparently affecting propulsion. GABAB-receptors are associated with a reduction of neural (mainly cholinergic) activity subserving muscular tone and peristalsis and appear to be located on both cholinergic and NANC inhibitory nerves. However, the persisting propulsive activity during suppression of GABAA- and GABAB-receptor function suggests that GABA in enteric neurones is not crucial for the neural circuitry subserving colonic peristalsis in this species.
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PMID:An in vitro study of the relationship between GABA receptor function and propulsive motility in the distal colon of the rabbit. 255 56

Pretreatment of the guinea-pig ileum with capsaicin resulted consistently in depression of the neurogenic cholinergic contractions induced by the GABAA receptor agonists 3-aminopropane sulphonic acid (3-APS) and muscimol. Since capsaicin acts mainly by releasing and depleting substance P from its stores in intestinal nerves, it is likely that substance P plays a role in the response caused by GABAA-mimetic compounds, On the whole, our results suggest that excitatory responses to 3-APS and muscimol result from both direct and indirect activation of intrinsic intestinal cholinergic neurons innervating smooth muscle cells.
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PMID:Inhibitory action of capsaicin on cholinergic responses induced by GABAA agonists in the guinea-pig ileum. 302 97

Rabbit antisera (APS) against normal guinea pig peritoneal exudate polymorphonuclear leukocytes (PMN), when injected intraperitoneally three times within 24 h into guinea pigs, lead to a marked fall in the blood PMN count (below 100/mm3) 24-72 h after the injection and a mild depression in the number of circulating mononuclear leukocytes (MNC) at 36-72 h. APS treatment of guinea pigs led to a marked suppression of delayed hypersensitivity skin reactions in response to dinitrophenylated bovine gamma-globulin. The volume, induration, mean diameter of the reaction and leukocyte (both PMN and MNC) emigration into local sites were suppressed, as was, to a lesser extent, vascular permeability. Based on these observations it appears that circulating PMN are required for the full expression of delayed hypersensitivity reaction engendered by bovine gamma-globulin.
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PMID:The role of polymorphonuclear leukocytes in delayed hypersensitivity skin reactions: suppressive effects of anti-polymorphonuclear leukocyte serum. 611 6

Rats were injected systemically with different classes of gabergic agent in order to investigate gabergic involvement in limbic output. Agonists differed one from another in their effects on variable-interval self-stimulation: clonazepam (in repeatedly-tested rats), chlordiazepoxide and pentobarbitone had a strongly biphasic action, low doses being facilitatory and high doses depressant, whereas other agonists including valproate and 3-APS (homotaurine) were uniformly depressant. The facilitatory effects of the benzodiazepines were dramatically enhanced by GABA antagonists (picrotoxin or pentylenetetrazol) even though antagonists on their own produced a dose-dependent depression that was not reversible by other anticonvulsant drugs. Ventral tegmental electrode placements yielded generally similar results. Depression of self-stimulation observed on initial exposure to clonazepam was reversed by repeated self-stimulation testing in the drugged state but not by repeated daily injections without testing. Locomotor activity (under conflict-free conditions) was unaffected or was depressed both by agonists and by antagonists. Thus, the facilitation of self-stimulation by chlordiazepoxide, pentobarbitone and clonazepam appears to be accounted for in terms of non-gabergic anti-conflict activity by these agents. Self-stimulation and locomotor changes following systemic administration did not disclose facilitatory effects attributable to gabergic efferents from limbic dopamine areas.
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PMID:Anti-conflict and depressant effects by GABA agonists and antagonists, benzodiazepines and non-gabergic anticonvulsants on self-stimulation and locomotor activity. 613 25

In isolated segments of guinea-pig small intestine, gamma-aminobutyric acid (GABA) (3-300 microM), the GABAA receptor agonist 3-aminopropane sulphonic acid (3-APS) (3-300 microM) and ivermectin (1-300 microM) caused concentration-dependent nerve-mediated cholinergic contractions sensitive to tetrodotoxin (1 microM) and hyoscine (1 microM). The EC50 values were 30.2 +/- 4.3, 24.6 +/- 3.1 and 4.8 +/- 0.6 microM, respectively. Picrotoxinin (10 microM), an allosteric blocker of the Cl- channel associated with GABAA receptors, non-competitively antagonized the contractile response caused by each agonist. Like picrotoxinin, lindane (10, 30 microM) caused a dose-related shift to the right of the concentration-response curve to GABA, 3-APS and ivermectin with depression of the maximum response. SR 95531 (3 microM), a competitive antagonist of GABAA receptors, caused a parallel dextral shift of the concentration-response curve to ivermectin with an apparent single point pA2 value of 6.5. Our results suggest that ivermectin and lindane, two neurotoxic pesticides interfering with central GABAErgic transmission, exert agonist and non-competitive antagonist properties at the enteric GABAA receptor-ionophore complex. This peripheral complex can thus be considered as an additional target for the action of both these compounds.
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PMID:Interaction of the neurotoxic pesticides ivermectin and lindane with the enteric GABAA receptor-ionophore complex in the guinea-pig. 768 58

We report organisation principles and three year experience of Acute Pain Service in general surgery clinic. 481 patients were treated after abdominal and vascular interventions, hemorrhoidal varices and mammectomies. Continuous epidural, combined spinal-epidural, intrapleural anaesthesia and continuous brachial plexus block were used for pain control. Time of analgesia varied from 1 to 4 days. The level of analgesia was assessed as good (VAS 3) in 94.8% of cases. Complications were mainly technical due to catheter or antibacterial filter failure. In 2% of cases cardiovascular complications were observed. Respiratory depression occurred in 1 patient. The work of APS team was assessed as very good by both surgeons and patients.
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PMID:[Organization of services for treatment of postoperative pain--3-year experience]. 985 8

This study investigated the relationship between posttraumatic stress disorder (PTSD) symptomatology and suicidal behavior, specifically suicidal ideation and suicide attempt history, while controlling for depression and gender in 106 adolescents in an urban high school. Participants completed self-report measures of the Adolescent Psychopathology Scales-Posttraumatic Stress Disorder Subscale (APS-PTS), the APS-Suicide Attempt History (APS-SAH), the Suicidal Ideation Questionnaire-Junior (SIQ-JR), and the Reynolds Adolescent Depression Scale (RADS). Analyses were conducted using a hierarchical multiple regression design to account for the relationship between PTSD symptomatology and depression. Regression results showed that after controlling for depression and gender, PTSD symptomatology was significantly related to suicidal ideation and showed a trend toward suicide attempt history. In addition, adolescents with high levels of PTSD symptomatology were more likely than peers with "average" levels of PTSD symptomatology to be currently thinking about suicide and to have made a past suicide attempt. These findings show that PTSD symptomatology has a unique relationship to adolescent suicidal behavior that cannot be explained by depression or gender. The importance of these results and their implications for future research are discussed.
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PMID:The relationship between posttraumatic stress symptomatology and suicidal behavior in school-based adolescents. 1088 51

Antiphospholipid antibodies (aPL) have been most strongly associated with a syndrome (APS) characterized by venous and/or arterial thrombosis, thrombocytopenia, recurrent fetal losses and a variety of non-thrombotic and thrombotic neurological disorders. Cerebral ischemia associated with aPL is the most common arterial thrombotic manifestation. Other neurological syndromes, such as cognitive dysfunction, dementia, psychosis, depression, seizures, chorea and transverse myelopathy, have all been associated with antiphospholipid antibodies.
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PMID:Neurological involvement in antiphospholipid antibodies syndrome (APS). 1107 18


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