Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0220723 (PCA)
 4,687 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

By use of a simple anticonflict procedure (Vogel test), it was demonstrated that L-pyroglutamic acid (L-pyrrolidone carboxylic acid [L-PCA]), an amino acid naturally occurring in mammalian tissues and fluids, possesses anxiolytic activity. This tissues and fluids, possesses anxiolytic activity. This effect was stereospecific (D-PCA was inactive) and, in the rat, it was not associated with a decrease in motor activity. Ro 15-1788, a benzodiazepine antagonist, did not modify L-PCA actions. Furthermore, anxiolytic doses of the amino acid did not change the content of 5-hydroxytryptamine (5-HT) or of 5-hydroxyindoleacetic acid (5-HIAA) in the rat cortex and hippocampus. These results suggest that the mechanism of the anxiolytic activity of L-PCA is different from that of the benzodiazepines and of 5-HT1a agonists.
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PMID:A new endogenous anxiolytic agent: L-pyroglutamic acid. 245 80

1. Reserpine (2.5 mg kg-1 i.p.) decreased rat brain 5-hydroxytryptamine (5-HT) by 86% 24 h later but most components of the 5-HT-dependent behavioural syndrome induced by p-chloroamphetamine (PCA, 5 mg kg-1 i.p.) or 5-methoxy-N,N-dimethyltryptamine (5-MeODMT, 5 mg kg-1 i.p.) over 1 h after administration were unaffected. However, Straub tail was increased after giving PCA or 5-MeODMT and head weaving was decreased after giving 5-MeODMT. 2. Frontal cortex extracellular 5-HT concentrations of vehicle pretreated rats before injection of PCA, as calculated from dialysate 5-HT concentrations, were about 1/1000th of corresponding brain values. Extracellular 5-hydroxyindoleacetic acid (5-HIAA) and brain values were comparable with each other. Dialysate 5-HT increased after PCA with peak values at 20-40 min. 3. Reserpine pretreatment reduced dialysate 5-HT concentration before PCA was given but the net increase (AUC) over the 1 h after PCA did not differ significantly from that seen in animals pretreated with vehicle. Dialysate 5-HIAA values slowly decreased after PCA injection in both reserpine and vehicle pretreated groups. 4. The results suggest that PCA causes the 5-HT syndrome by releasing 5-HT from the neuronal cytoplasm but that physiological release of 5-HT occurs from vesicular stores.
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PMID:An in vivo dialysis and behavioural study of the release of 5-HT by p-chloroamphetamine in reserpine-treated rats. 272 Mar 8

Biosensors sensitive for in vivo monitoring of serotonin (5-HT) in the CNS by differential normal pulse voltammetry were constructed by coating treated multicarbon fiber electrodes (mCFEs) with Nafion (N-mCFE). In vitro sensitivities of mCFE and N-mCFE were compared in solutions ranging from 5 nM to 20 microM of uric acid (UA), 5-hydroxyindoleacetic acid (5-HIAA), and 5-HT. The mCFEs were three to seven times less sensitive for 5-HIAA or UA than for 5-HT. Nafion treatment dramatically decreased sensitivity for 5-HIAA and UA of N-mCFEs (approximately 10(3) times), whereas it remained in the nanomolar range for 5-HT. In vivo, in the dorsal horn of the lumbar spinal cord of anesthetized rats, the monoamine oxidase inhibitor clorgyline (10 mg/kg i.p.) produced a reduction (55 +/- 3% at 180 min) of peak 3 of oxidation current (characteristic of 5-hydroxyindoles) monitored with mCFEs, but with N-mCFEs (in this latter case the peak was termed 3N) peak 3N increased to 135 +/- 5% at 180 min. The 5-HT release-inducer p-chloroamphetamine (PCA; 6 mg/kg i.p.) induced a slight (12 +/- 3% at 150 min) decrease in peak 3 measured with mCFEs, whereas with N-mCFEs PCA induced a rapid increase of peak 3N (137 +/- 6% at 90 min). The xanthine oxidase inhibitor allopurinol (10 mg/kg i.p.) produced a decrease (30 +/- 3% at 180 min) in peak 3 (mCFEs), but peak 3N (N-mCFEs) was not affected (106% at 180 min). After pretreatment with allopurinol, PCA also produced an increase (135 +/- 6% at 90 min) in peak 3N.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:In vivo electrochemical monitoring of serotonin in spinal dorsal horn with Nafion-coated multi-carbon fiber electrodes. 754 31

Changes in the level of dopamine (DA) and its metabolites [3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA)] and serotonin (5-HT) and its metabolite [5-hydroxyindoleacetic acid (5-HIAA)] were determined sequentially in freely moving rats by using a brain dialysis method. The purpose of the study was to find the relationship between changes in the monoamine metabolism in the nucleus accumbens and locomotor activities following PCA administration. Subsequently it was found that locomotor activity significantly increased 1 and 2 h after PCA administration (2 mg/kg, i.p.) while the DA content in the dialysis fluid rose significantly after 1 and 2 h. On the other hand, the 5-HT level did not show significant changes. The DOPAC, HVA, and 5-HIAA levels were significantly reduced 1 to 6 h after PCA administration. It was suggested that the increase in locomotor activity caused by PCA administration is an expression of abnormal behavior caused by DA release from the nucleus accumbens.
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PMID:Effect of p-chloroamphetamine administration on monoamine metabolism in the rat nucleus accumbens and locomotor activity: studies with intracerebral dialysis in freely moving rats. 783 49

The effects of p-chlorophenylalanine (PCPA, 100-150 mg/kg x 1. i.p.), doses which decrease brain 5-hydroxytryptamine (5-HT) by 30-50%, were investigated in both intact rats and 14 days after giving p-chloroamphetamine (PCA, 10 mg/kg/day x 2, i.p.). The PCPA dose-dependently decreased brain regional 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) 24 hr later. As per cent decreases of 5-HIAA were greater than those of 5-HT in cortex, striatum and hippocampus 5-HIAA/5-HT ratios fell, suggesting that partial inhibition of 5-HT synthesis by PCPA increases 5-HT conservation in these terminal regions. In the hypothalamus and brain stem, decreases of the ratio were small or absent. The PCA given without subsequent PCPA treatment decreased 5-HT and 5-HIAA so that 5-HT fell by about 70% in the cortex, striatum and hippocampus, 55% in the brain stem but only by 27% in the hypothalamus. The PCPA given after PCA decreased 5-HT and 5-HIAA further but not the 5-HIAA/5-HT ratios and increased the ratio in the brain stem. The 5-HIAA/5-HT findings imply that the increase of 5-HT conservation after PCPA treatment does not occur after partial depletion of 5-HT by PCA. The increase of the 5-HIAA/5-HT ratio in the brain stem is explicable by the resistance to both PCA and PCPA of 5-HT in cell bodies where the ratio is high. Results are discussed in relation to the question of whether the PCA treatment used destroys axon terminals projecting from the dorsal but not from the median raphe.
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PMID:Effect of p-chlorophenylalanine at moderate dosage on 5-HT and 5-HIAA concentrations in brain regions of control and p-chloroamphetamine treated rats. 878 6

Three serotonin (5-HT) neurotoxins, p-chlorophenylalanine (PCPA, 125 and 250 mg/kg, i.p.), p-chloroamphetamine (PCA, 10 mg/kg, i.p.) and 5,7-dihydroxytryptamine (5,7-DHT, 200 microg/rat, i.c.v.) were used to examine whether depletion of central 5-HT has an effect on central dopaminergic (DA) neuronal activities or on prolactin (PRL) secretion. Adult ovariectomized Sprague-Dawley rats primed with estrogen (polyestradiol phosphate, 0.1 mg/rat, s.c.) were treated with one of three neurotoxins and then decapitated in the morning after 3-7 days. Blood sample and brain tissues were collected. The acute effect of PCA (from 30 to 180 min) was also determined. The concentrations of 5-HT, DA and their metabolites, 5-hydroxyindoleacetic acid and 3,4-dihydroxyphenylacetic acid, in the median eminence, striatum and nucleus accumbens were determined by HPLC-electrochemical detection. All three toxins significantly depleted central 5-HT stores by 11-20%. Except for PCPA, neither PCA nor 5,7-DHT had any significant effect on basal DA neuronal activities or PRL secretion. PCA also exhibited an acute effect on the release and reuptake of 5-HT and DA. In summary, depletion of central 5-HT stores to a significant extent for 3-7 days did not seem to affect basal DA neuronal activity and PRL secretion.
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PMID:Effects of serotonin depletion by p-chlorophenylalanine, p-chloroamphetamine or 5,7-dihydroxytryptamine on central dopaminergic neurons: focus on tuberoinfundibular dopaminergic neurons and serum prolactin. 1034 67