Search results for "Phenylacetic acid"
showing 10 items of 22 documents
Effect of intermittent exposure to ethanol and MDMA during adolescence on learning and memory in adult mice
2012
Abstract Background Heavy binge drinking is increasingly frequent among adolescents, and consumption of 3,4-methylenedioxymethamphetamine (MDMA) is often combined with ethanol (EtOH). The long-lasting effects of intermittent exposure to EtOH and MDMA during adolescence on learning and memory were evaluated in adult mice using the Hebb-Williams maze. Methods Adolescent OF1 mice were exposed to EtOH (1.25 g/kg) on two consecutive days at 48-h intervals over a 14-day period (from PD 29 to 42). MDMA (10 or 20 mg/kg) was injected twice daily at 4-h intervals over two consecutive days, and this schedule was repeated six days later (PD 33, 34, 41 and 42), resulting in a total of eight injections. …
Day- and night-time contents of monoamines and their metabolites in the medial preoptic area of the rat hypothalamus.
1999
The present study was conducted to investigate whether monoamines and their metabolites in the medial preoptic area (mPOA) of the rat hypothalamus exhibit differences in their contents between day and night. We therefore sampled the mPOA from adult animals of either sex at the middle of the light or dark period, respectively, and analyzed the tissue by means of high performance liquid chromatography with electrochemical detection. We found that, in female animals at mid-night, dopamine and 3,4-dihydroxyphenyl acetic acid (DOPAC) was reduced to 43 and 30%, respectively, of daytime levels, while the norepinephrine content was doubled. No significant differences were observed in male animals. …
Opposite effects of γ1- and γ2-melanocyte stimulating hormone on regulation of the dopaminergic mesolimbic system in rats
2004
By use of the brain microdialysis technique we show that administration of gamma(1)-melanocyte stimulating hormone (gamma(1)-MSH) into the ventral tegmental area of anaesthetized rats causes an increase in the release of extracellular dopamine and its metabolite 3,4-dihydroxyphenylacetic acid in the nucleus accumbens, while gamma(2)-MSH causes the opposite effect. Moreover, gamma(2)-MSH pre-treatment considerably reduced the gamma(1)-MSH-induced effects. Our findings suggest an opposing action of two gamma-MSH-activated pathways on the mesolimbic dopaminergic system, which could be important in the maintenance of a balanced psychoactivation state.
Mesolimbic dopaminergic system activity as a function of food reward: A microdialysis study
1996
The mesolimbic dopaminergic system (MDS) has been shown to be implicated in feeding behaviors. The present experiment was conducted to examine the effects of the sensory properties of food ingested on MDS activity. Microdialysis coupled to high-performance liquid chromatography with electrochemical detection was employed to measure the extracellular levels of dopamine (DA) and its main metabolites (DOPAC and HVA) in the nucleus accumbens of freely moving rats. During microdialysis sessions rats had access or not to powdered foods varying in palatability: short cakes as highly palatable (HP) food and regular chow as low palatable (LP) food. In the absence of food, there were no alterations i…
Presence of plant hormones in composts made from organic fraction of municipal solid waste
2016
Composting is a process of the biological decomposition of organic matter under aerobic conditions. Composts made from waste may still contain other substances that influence plant growth and development, such as vitamins or plant growth substances (plant hormones). Application of products containing phytohormones has an effect on numerous physiological processes in plants. Among observable results are: improved condition of the root system, increased absorption of nutrients, improved stress and disease resistance and delayed aging. The purpose of the research was to analyse the occurrence of plant hormones in mature composts made from selectively collected organic fraction of household mun…
Presynaptic regulation of the electrically evoked release of endogenous dopamine from the isolated neurointermediate lobe or isolated neural lobe of …
1988
Isolated neurointermediate lobes (NILs) or isolated neural lobes (NLs) of the rat pituitary gland were incubated in Krebs-HEPES solution which contained pargyline and the dopamine uptake inhibitor GBR 12921. The release of endogenous dopamine was determined by HPLC with electrochemical detection. Electrical stimulation of the pituitary stalk induced a frequency-dependent release of dopamine. The release of dopamine from the combined NIL evoked by stimulation at 15 Hz was increased by 130% in the presence of the dopamine D2 receptor antagonist, (-)-sulpiride; the (+)-enantiomer of sulpiride had virtually no effect. When the stimulation frequency was 3 Hz (-)-sulpiride caused an increase in d…
The role of cytoplasmic (newly synthesized) dopamine for the spontaneous and electrically evoked release of dopamine and its metabolites from the iso…
1987
Isolated rat NILs were incubated in Krebs-HEPES solution. The release of dopamine and its metabolites (DOPAC, HVA and MOPET) was determined by HPLC with electrochemical detection. The spontaneous release of the sum of metabolites was about 40 times that of dopamine. The spontaneous outflow of dopamine metabolites was unaffected after inhibition of dopamine uptake (by GBR 12921) or after pretreatment with reserpine (5 mg/kg, 12 h before the experiments), but it was reduced by 50% after preincubation with the irreversible DOPA decarboxylase inhibitor, (MFMD, 10 microM, for 10 min). The combination of pretreatment with reserpine and preincubation with MFMD resulted in an 80% inhibition of the …
Absorption-partition relationships for true homologous series of xenobiotics as a possible approach to study mechanisms of surfactants in absorption.…
1992
Abstract This paper — the latest in this series of reports — deals with the effects of the anionic surfactant sodium lauryl sulfate on the colonic absorption of acidic xenobiotics (phenylalkylcarboxylic acids), as compared with those exerted by the nonionic polysorbate 80. The effects of these surfactants are qualitatively identical but quantitatively different. Thus, the increase in polarity of the colonic absorbant membrane is greater with lauryl sulfate, whereas micellar solubilization is much higher with polysorbate. As for the rest (i.e. the elimination of the stagnant aqueous diffusion layer as a limiting step for absorption), the two surfactants behave in a similar way. The biopharma…
Electrochemical carboxylation of benzal chloride
1984
Abstract The clectrocarboxylation of benzal chloride to -chlorophenylacetic and phenylmalonic acids is realized in diaphragmless cells with aluminium sacrificial anodes. Yields respectively up to 50% and 30% can be obtained. Phenylacetic acid is always present among the products.
Über die depolymerisation von polyoxymethylendiolen, katalysiert durch carbonsäuren. 38. Mitt. Über polyoxymethylene1
1969
Nach einem Uberblick uber bisherige Arbeiten uber den Mechanismus des sauer katalysierten Abbaus von Polyoxymethylendiolen wird der Abbau in 1-proz. Losung in Nitrobenzol bei 135°C unter dem Einflus verschiedener Carbonsauren untersucht. Phenylessigsare verursacht keine nennenswerte Kettenspaltung, sondern katalysiert lediglich die Depolymerisation an den halbacetalischen Kettenenden. Die Depolymerisationsgeschwindigkeit ist etwa proportional der Saurekonzentration und umgekehrt proportional dem Polymerisationsgrad. Wahrend des Abbaus andert sich der durchschnittliche Polymerisationsgrad nicht wesentlich. Diese Befunde lassen sich mit keinem der diskutierten Reaktionsmechanismen widerspruch…