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Brain Research Dec 1987Arachidonate 5 x 10(-5) mol.l-1 increased the rate of hyperpolarization induced in Na+-loaded mouse diaphragm fibers by 5 mmol.l-1 K+. When applied to Na+-loaded muscles...
Arachidonate 5 x 10(-5) mol.l-1 increased the rate of hyperpolarization induced in Na+-loaded mouse diaphragm fibers by 5 mmol.l-1 K+. When applied to Na+-loaded muscles without potassium, arachidonate 1 x 10(-6) and 5 x 10(-5) mol.l-1 induced a ouabain-sensitive hyperpolarization of the muscle fibers. The activity of rat brain microsomal Na+,K+-ATPase was stimulated by 1 x 10(-7)-5 x 10(-6) mol.l-1 arachidonate in reaction media with reduced amounts of ATP or K+ and after short-lasting sonication of the samples. It was concluded that, under particular conditions, arachidonate might serve as a Na+,K+-ATPase activator or inhibitor regulating its ion transport and electrogenicity.
Topics: Animals; Arachidonic Acids; Brain; Diaphragm; Electrophysiology; Female; In Vitro Techniques; Mice; Microsomes; Muscles; Potassium; Sodium; Sodium-Potassium-Exchanging ATPase
PubMed: 2825927
DOI: 10.1016/0006-8993(87)91559-9 -
Journal of Immunological Methods Jul 1988A counterimmunoelectrophoresis (CIE) test for the detection of liver-kidney microsome specific antibodies in human sera is described. By testing different subcellular...
A counterimmunoelectrophoresis (CIE) test for the detection of liver-kidney microsome specific antibodies in human sera is described. By testing different subcellular preparations the LKM antigen was found in the membranes of the smooth endoplasmic reticulum subfraction. The antigen was sensitive to trypsin digestion and behaved as an anionic protein in the experimental conditions used in the test. All sera positive for LKM in immunofluorescence gave a precipitin line of identity while none of the control sera gave a positive reaction. The CIE titers ranged between neat and 1/4096. A significant correlation was observed between the LKM titers obtained in immunofluorescence and those obtained in CIE. Moreover, by absorption experiments, it was concluded that the antigen preparation reactive in CIE was able to abolish the immunofluorescence pattern of LKM positive sera on rat liver and kidney sections. The LKM target antigen, although previously considered a structural protein of microsomal membranes, was shown to solubilize spontaneously during the isolation of microsomal membranes. Counterimmunoelectrophoresis appears to be an appropriate test for anti-LKM antibodies in human sera.
Topics: Autoantibodies; Cell Fractionation; Chronic Disease; Endoplasmic Reticulum; Humans; Immunoelectrophoresis, Two-Dimensional; Intracellular Membranes; Kidney; Liver Diseases; Microsomes; Microsomes, Liver
PubMed: 3397549
DOI: 10.1016/0022-1759(88)90134-2 -
Archives of Dermatology Nov 1991
Topics: Adolescent; Autoantibodies; Female; Hepatitis, Chronic; Humans; Hyperthyroidism; Kidney; Lichen Planus; Microsomes; Microsomes, Liver; Ultrasonography
PubMed: 1952987
DOI: No ID Found -
Chemical Research in Toxicology Mar 2003Cocaine metabolism has been studied previously with respect to the formation of predominant hydrolytic or hepatotoxic metabolites via oxidative pathways. In the present...
Cocaine metabolism has been studied previously with respect to the formation of predominant hydrolytic or hepatotoxic metabolites via oxidative pathways. In the present study, cocaine and eight of its metabolites (norcocaine, ecgonine methyl ester, benzoylecgonine, benzoylnorecgonine, 3-hydroxy-benzoylecgonine, cocaethylene, norcocaethylene, and ecgonine ethyl ester) were incubated with microsomes from rat liver, kidney, lung, and brain. Qualitative analysis of the metabolites produced was performed using solid phase extraction (SPE), trimethylsilylation, and GC/MS. It was found that the metabolites with a free carboxylic group (e.g., benzoylecgonine) were not further oxidized by microsomal enzymes and their presence in urine or blood may therefore be due to hydrolysis of the respective alkylated entities. Although microsomes from all organs exhibited oxidative metabolism, significant differences were noted. Kidney microsomes produced essentially the same results as liver, but aryl hydroxylated metabolites were not found in incubations with lung and brain microsomes. N-Hydroxy-norcocaine was found only in traces with brain microsomes. It appears that cocaine is converted to N-hydroxy-norcocaine (which is the precursor of toxic metabolites) not only in the liver but also in other organs of rat. This might be relevant in the development of lung toxicity observed in smokers of cocaine ("crack").
Topics: Animals; Brain; Cocaine; Gas Chromatography-Mass Spectrometry; Hydrolysis; Kidney; Lung; Male; Microsomes; Microsomes, Liver; Oxidation-Reduction; Rats; Rats, Sprague-Dawley; Tissue Distribution
PubMed: 12641438
DOI: 10.1021/tx025580n -
Cancer Letters Dec 1988Phenolic antioxidants such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are known to inhibit tumor formation due to several chemical carcinogens...
Phenolic antioxidants such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are known to inhibit tumor formation due to several chemical carcinogens including aflatoxin B1 (AFB1). Metabolic activation of AFB1 by lung microsomes and possible modification by dietary BHA was reported in an earlier communication (Allameh et al. (1988) Cancer Lett., 40, 49). Here we report the effect of dietary BHA at a high dose (0.75% for 15 days) and a low dose (0.06% for 180 days) on the activation and inactivation of AFB1 by subcellular preparations of lung. BHT at high dose alone induced hepatic cytosolic glutathione (GSH) S-transferases activity while the pulmonary enzyme was unaffected by BHT feeding. This observation was substantiated when the addition of lung cytosol from control and BHT-treated rats showed similar inhibition (50%) in the microsome mediated AFB1-DNA binding. Thus BHT appears to have little influence on the pulmonary metabolism of AFB1.
Topics: Aflatoxin B1; Aflatoxins; Animals; Butylated Hydroxytoluene; DNA; Glutathione Transferase; Lung; Male; Microsomes; Rats; Rats, Inbred Strains
PubMed: 3144431
DOI: 10.1016/0304-3835(88)90224-8 -
European Journal of Drug Metabolism and... 1986The biotransformation kinetics of Ketamine in 10,000 g supernatant fractions of liver and lung homogenates was studied. The products found in the incubation mixtures by...
The biotransformation kinetics of Ketamine in 10,000 g supernatant fractions of liver and lung homogenates was studied. The products found in the incubation mixtures by gas chromatography and mass spectrometry were identified. In the two homogenates studied it was only possible to detect and identify metabolite I of ketamine. This study enabled us to characterize the kinetic parameters in order to define the biotransformation of ketamine (Km and Vmax) in the two organs studied. The lung enzyme systems were found to be more easily saturable than those of the liver. Furthermore, the fact that all of the ketamine is biotransformed and only 60% of metabolite norketamine appears suggests the existence of parallel biotransformation pathways for this anaesthetic.
Topics: Animals; Biotransformation; Chromatography, Gas; In Vitro Techniques; Ketamine; Kinetics; Lung; Male; Mass Spectrometry; Microsomes; Microsomes, Liver; Rabbits
PubMed: 3720798
DOI: 10.1007/BF03189769 -
Prostaglandins Mar 1973
Topics: Animals; Arachidonic Acids; Aspirin; Chromatography, Thin Layer; Depression, Chemical; In Vitro Techniques; Indomethacin; Male; Microsomes; Powders; Prostaglandins; Seminal Vesicles; Sheep; Tritium
PubMed: 4729577
DOI: 10.1016/0090-6980(73)90072-5 -
Molecular Pharmacology Mar 1966
Topics: Animals; Cytochromes; In Vitro Techniques; Liver; Male; Microsomes; Rats
PubMed: 5905665
DOI: No ID Found -
Brain Research May 1996The distribution and subcellular localization of AH9 antigen, recognized by a monoclonal antibody AH9, were examined in rat brain. Highest expression was observed in the... (Comparative Study)
Comparative Study
The distribution and subcellular localization of AH9 antigen, recognized by a monoclonal antibody AH9, were examined in rat brain. Highest expression was observed in the lamina lucidum of the dentate gyrus of the rat hippocampus. Synaptic subfields of other limbic areas also expressed AH9 antigen at a substantial level. The molecular size of the AH9 antigen is 15 kDa and it was found in the microsomal fraction of brain but not of heart or kidney. These results indicate that AH9 antigen is a novel synaptosomal protein that is relatively specific to the limbic system, at least in the rat brain. We designated AH9 antigen as a limbic system associated protein-1, lap-1.
Topics: Animals; Antibodies, Monoclonal; Antigen-Antibody Reactions; Brain; Humans; Limbic System; Mice; Mice, Inbred BALB C; Microsomes; Rats; Rats, Wistar
PubMed: 8782880
DOI: 10.1016/0006-8993(95)01344-x -
Folia Microbiologica Jan 2016Recent studies documented that several processes in filamentous fungi are connected with microsomal enzyme activities. In this work, microsomal subproteomes of Pleurotus...
Recent studies documented that several processes in filamentous fungi are connected with microsomal enzyme activities. In this work, microsomal subproteomes of Pleurotus ostreatus were analyzed by two-dimensional (2-D) polyacrylamide gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry analysis. To assess proteome dynamics, microsomal proteins were isolated from fungal cultures after 7 and 12 days of cultivation. Additionally, 10 mg/L of 17α-ethinylestradiol (EE2) was treated with the cultures during 2 days. Despite the EE2 degradation by the fungus reached 97 and 76.3 % in 7- and 12-day-old cultures, respectively, only a minor effect on the composition of microsomal proteins was observed. The changes in protein maps related to ageing prevailed over those induced by EE2. Epoxide hydrolase, known to metabolize EE2, was detected in 12-day-old cultures only which suggests differences in EE2 degradation pathways utilized by fungal cultures of different age. The majority (32 %) of identified microsomal proteins were parts of mitochondrial energy metabolism.
Topics: Electrophoresis, Gel, Two-Dimensional; Fungal Proteins; Microsomes; Pleurotus; Proteome; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 26122365
DOI: 10.1007/s12223-015-0410-2