During simulated weightlessness and spaceflight, variations in plasma and urinary catecholamine(GA) levels haute been observed. The alterations of metabolism of CA In liver, the main site of metabolism, ate yet not known We measured the activity of catechol-O-methyl transferase (COMT) and monoamine oxidase (MAO) In rat liver as Indicators of CA metabolism before and during head-down suspension The rats were placed In a -45 degress antiorthostatic position for 2 weeks. Head-down suspension resulted In decrease other hepatic MAO B activity By contrast, the activities of other hepatic degrading enzymes, COMT and MAO A, did not altered These findings Indicate that a prolonged exposure to simulated weightlessness exerts no remarkable effect on CA degradation in rat liver.
Animals ; Liver* ; Metabolism ; Monoamine Oxidase ; Plasma ; Rats* ; Space Flight ; Transferases ; Weightlessness

The effects of 7-ethyl-8-methylf1avin (7-Et) and 7-methyl-8-ethyl-flavin (8-Et) on rat hepatic monoamine oxidase (MAO), brain MAO activity and 5-hydroxytryptamine (5-HT or serotonin) in rat brain were investigated. In the study of hepatic MAO activity, kynur-amine a nonphysiological substrate for both A and B type MAO, was used for a spectro-photometric method, and [14C]-labeled amines were also used for a radiometric procedure for camparison with MAO activity determined by the spectrophotometric method. The rate of change in MAO activity of hepatic mitochondria from rats receiving Rb-def and 7-Et and 8-Et flavin showed the activity was severely reduced during 8 weeks. Rapid reduction of enzyme activity (50% in def-group, 35% in 7-Et group and 8% 8-Et flavin group) was observed at the end of 2 weeks. The enzyme activity lasted with slow decre-ment of enzyme level from 4 weeks to the end of 8 weeks as low as 16% in def, 18% in 7-Et and 3% in 8-Et flavin group. The trend of decrement of MAO activity when kynura-mine was used as a substrate appears to be similar with the small variation of MAO activity when [14C]-labelled tyramine, dopamine, serotonin and tryptamine respectively were used as substrate. The rate of decay of brain mitochondrial MAO activity in rats receiving each respective f1avin was not rapid and severely depressed as the MAO activity we have found in liver mitochondrial MAO of rats during the 8 week experimental time, but a similar tendency of decay of MAO in each group was observed. The potent inhibitory effect of 8-Et on brain MAO was confirmed by the study of the simultaneous measure-ment of MAO activity in each experimental group. when the reduction Of brain MAO activity in rats receiving 8-Et after 6 weeks was approximately 80% of normal and in the same rats the concentration of brain 5-HT showed a 60% increment of that of the normal mts. During the experimental period there is no absolute parallelism between the MAO inhibition and 5-HT increase. However when the reduction of MAO activity reached 80% of normal value, the concentration of 5-HT increased dramatically as much as 60% of normal value. The results so far suggest clearly that 8-Et produces a much more potent inhibitory effect on the hepatic MAO a s well as brain MAO in rats. Therefore our present and previous results suggest that 7-Et and 8-Et flavin should bind itself to hepatic, brain MAO apoenzyme in the condition of total absence of riboflavin in these animals, and the holenzyme is catalytically inactive.
Animal ; Brain/enzymology* ; Brain/metabolism ; Comparative Study ; Male ; Mitochondria/enzymology* ; Mitochondria, Liver/enzymology* ; Monoamine Oxidase/metabolism* ; Rats ; Serotonin/metabolism*

This study was done in order to show the effects of carbon rnonoxide (CO) induced hypoxia on the steps of metabolism of rnonoamine neurotransmitters. There were 9 patients exposed to CO and 5 patients of control group. We evaluated their cerebrospinal fluid within 24 hours after CO exposure. And we measured the amounts of 5-hydroxy-indole acetic acid (5-HIAA) and homovanillic acid (HVA) with high performance liquid chromatography (HPLC). In the CO exposure group, the levels of 5-HIAA and HVA were reduced compared with the control group. It was thought that the changes in the levels of 5-HIAA and HVA were due to the transient decrease in monoamine oxidase activity in acute hypoxia.
Acetic Acid ; Anoxia ; Carbon Monoxide* ; Carbon* ; Cerebrospinal Fluid ; Chromatography, Liquid ; Homovanillic Acid ; Humans* ; Hydroxyindoleacetic Acid ; Metabolism ; Monoamine Oxidase ; Neurotransmitter Agents*

The monoamine oxidase mutant A-1 (F210V/L213C) from Aspergillus niger showed some catalytic activity on mexiletine. To futher improve its activity, the mutant was subjected to directed evolution with MegaWHOP PCR (Megaprimer PCR of Whole Plasmid) and selection employing a high-throughput agar plate-based colorimetric screen. This approach led to the identification of a mutant ep-1, which specific activity was 189% of that for A-1. The ep-1 also showed significantly improved enantioselectivity, with the E value increased from 101 to 282; its kinetic k(cat)/K(m) value increased from 0.001 51 mmol/(L x s) to 0.002 89 mmol/(L x s), suggesting that catalytic efficiency of ep-1 had been improved. The mutant showed obviously higher specific activities on 7 of all tested 11 amines substrates, and the others were comparable. Sequence analysis revealed that there was a new mutation T162A on ep-1. The molecular dynamics simulation indicated that T162A may affect the secondary structure of the substrate channel and expand the binding pocket.
Aspergillus niger ; enzymology ; Catalysis ; Kinetics ; Monoamine Oxidase ; genetics ; metabolism ; Mutation ; Polymerase Chain Reaction ; Protein Engineering ; Protein Structure, Secondary ; Substrate Specificity

OBJECTIVETo study immunomodulating activity of Lonicera Japonica flavone by investigating immune enzymatic activity of serum and antoxidized activity of lymphoid organs in mice.

METHODSFifty KM mice were randomly divided into control group, model group, low dose group, middle dose group and high dose group(n = 10), respectively. And low dose group, middle dose group and high dose group were given Lonicera Japonica flavone with 100 mg/kg, 200 mg/kg and 400 mg/kg every day, respectively, while control group and model group were administered with NS. After continuously giving drug 7 weeks, other groups were injected with Dexamethasome (Dex: 25 mg /kg) for 3 days by subcutaneous injection, but the control group were treated with NS. And after giving Lonicera Japonica flavone 1 week simultaneously, organ indexes , the activity of acid phosphatase (ACP), alkaline phosphatase (AKP) and lysozyme (LSZ) in serum , and the content of monoamine oxidase (MAO), total antioxidant capacity (T-AOC), total superoxide dismutase (SOD) and malondialdehyde (MDA) in lymphoid organs in mice were tested, respectively.

RESULTSLonicera Japonica flavone could significantly improve the organ indexes, and significantly improve the activity of ACP, AKP and LSZ in serum, and significantly improve the contents of T-AOC and SOD, but reduce that of MAO and MDA in lymphoid organs in immunosuppressed mice.

CONCLUSIONIonicera Japonica flavone can significantly improve the activity of immune enzyme in serum and the antioxidized activity of lymphoid organs in mice. It suggests that Ionicera Japonica flavone has a good immunomodulatory effects.

Acid Phosphatase ; blood ; Alkaline Phosphatase ; blood ; Animals ; Antioxidants ; metabolism ; Flavones ; pharmacology ; Immunomodulation ; Lonicera ; chemistry ; Malondialdehyde ; metabolism ; Mice ; Monoamine Oxidase ; metabolism ; Muramidase ; blood ; Superoxide Dismutase ; metabolism

OBJECTIVE: To investigate the impact of renal denervation on the blood pressure, plasma renalase content and expression of renalase and tyrosine hydroxylase (TH) in the idney of spontaneous hypertensive (SH) rats and to explore the role of renal denervation in lowering the blood pressure. METHODS: SH rats were randomly assigned into a baseline group, a surgery (renal denervation) group, a sham group and a control group (n=48). WKY rats matched in age (n=12) served as a baseline control group. All rats were housed until 12 weeks old. Then, the rats in the baseline group and the WKY group were sacrificed whose blood and kidney were collected for examination. In the renal denervation group, the sham group and the control group, the blood pressure was monitored continuously. One week and 6 weeks after the renal denervation, 6 rats in each group were sacrificed whose blood and kidney were collected. ELISA was employed to measure the plasma renalase and Western blot assay done to detect the expression of TH and renalase in the kidney. RESULTS: Compared with WKY rats, blood pressure significantly increased and TH protein expression markedly elevated (P<0.05) in SH rats in the baseline group, but plasma renalase content and protein expression of renalase in the kidney dramatically reduced (P<0.05). One week after the surgery, the mean arterial pressure and TH protein expression in the surgery group were lowered compared with the baseline group and dramatically reduced compared with the sham group and the control group (P<0.05). In the surgery group, the renalase level was markedly increased compared with the baseline group, the sham group, and the control group (P<0.05). Six weeks after the renal denervation, the mean arterial pressure and TH level in the surgery group were significantly increased but the renalase content and expression markedly reduced compared with those 1 week, but there were no marked differences among the surgery group, the sham group, and the control group (P>0.05). No pronounced differences in the above variables were found between the sham group and the control group at any time point (P>0.05). CONCLUSION Renal denervation can lower the blood pressure, which may attribute to the suppression of sympathetic nerves, increase in plasma renalase content and renalase expression in the kidney.
Animals ; Blood Pressure ; physiology ; Hypertension ; surgery ; Kidney ; enzymology ; innervation ; Male ; Monoamine Oxidase ; blood ; metabolism ; Rats ; Rats, Inbred SHR ; Sympathectomy ; methods ; Sympathetic Nervous System ; physiopathology ; Tyrosine 3-Monooxygenase ; metabolism

Medium-chain fatty acids (MCFAs) are mostly generated from dietary triglycerides and can penetrate the blood-brain barrier. Astrocytes in the brain use MCFAs as an alternative energy source. In addition, MCFAs have various regulatory and signaling functions in astrocytes. However, it is unclear how astrocytes sense and take up MCFAs. This study demonstrates that decanoic acid (DA; C10), a saturated MCFA and a ligand of G(αs) protein-coupled receptors (G(αs)-GPCRs), is a signaling molecule in energy metabolism in primary astrocytes. cAMP synthesis and lactate release were increased via a putative G(αs)-GPCR and transmembrane adenylyl cyclase upon short-term treatment with DA. By contrast, monoamine oxidase B-dependent gamma-aminobutyric acid (GABA) synthesis was increased in primary cortical and hypothalamic astrocytes upon long-term treatment with DA. Thus, astrocytes respond to DA by synthesizing cAMP and releasing lactate upon short-term treatment, and by synthesizing and releasing GABA upon long-term treatment, similar to reactive astrocytes. Our data suggest that astrocytes in the brain play crucial roles in lipid-sensing via GPCRs and modulate neuronal metabolism or activity by releasing lactate via astrocyte-neuron lactate shuttle or GABA to influence neighboring neurons.
Adenylyl Cyclases ; Animals ; Astrocytes* ; Blood-Brain Barrier ; Brain ; Energy Metabolism ; Fatty Acids ; gamma-Aminobutyric Acid* ; Lactic Acid* ; Metabolism ; Mice* ; Monoamine Oxidase ; Neurons ; Triglycerides

It has been well known that catecholamines (CAs) in the body, including norepinephrine (NE), epinephrine (E) and dopamine (DA), are synthesized and secreted by neurons and endocrine cells and mainly modulate visceral activities such as cardiovascular, respiratory and digestive functions. The studies over the past nearly 30 years have shown that CAs can also regulate immune function. The immunomodulation of CAs is generally considered as a role mediating the regulation of nervous and endocrine systems. However, recent studies reveal that immune cells can also synthesize CAs, which is an update of traditional concept. A classical metabolic pathway of CAs shared by the nervous and endocrine systems is present in the immune cells, i.e., the immunocytes have the enzymes for synthesis of CAs [e.g. tyrosine hydroxylase (TH)] and the enzymes for degradation of CAs [e.g. monoamine oxidase (MAO) and catechol-O-methyl transferase (COMT)]. The endogenous CAs synthesized by immune cells can regulate many immune functions, including cellular proliferation, differentiation, apoptosis and cytokine production. These roles of the endogenous CAs may be mediated by an autocrine/paracrine pathway via relevant receptors on the immunocytes and intracellular cAMP. Intracellular oxidative mechanism may also be involved in immunoregulation of endogenous CAs in immune cells. In addition, some metabolic abnormalities of CAs in the immune cells probably induce some autoimmune diseases, such as multiple sclerosis (MS) and rheumatoid arthritis. These findings not only provide evidence for the new concept that the immune system is possible to become the third CA system other than the nervous and endocrine systems, but also extend our comprehension on functional significance of the endogenous CAs synthesized by immune cells.
Animals ; Autoimmune Diseases ; immunology ; Catecholamines ; physiology ; Humans ; Immune System ; physiology ; Lymphocytes ; immunology ; metabolism ; Monoamine Oxidase ; physiology ; Neuroimmunomodulation ; physiology ; Tyrosine 3-Monooxygenase ; physiology

BACKGROUND/OBJECTIVES: There are various factors that affect metabolic abnormalities related to obesity. The purpose of this study is to analyze the differences in dietary intakes and body compositions of obese women according to metabolic risks and to classify them as metabolically healthy obese (MHO) or metabolically abnormal obese (MAO). SUBJECTS/METHODS: This study was conducted on 59 obese Korean women aged 19 to 60 years. NCEP-ATPIII criteria were applied and the women classified as MHO (n = 45) or MAO (n = 14). Body composition of each subject was measured by using dual-energy x-ray absorptiometry (DEXA). Three-day food records were used to analyze dietary intake. Eating habits and health-related behaviors were determined through questionnaires. Indirect calorimetry was used to measure resting metabolic rate and respiratory rate. RESULTS: The average age of the subjects was 43.7 years. The analysis of body composition according to phenotype revealed significantly higher body fat mass (P < 0.05), arm fat mass (P < 0.05), and android fat mass (P < 0.05), as measured by DEXA, in the MAO group than in the MHO group. There was no significant difference in the dietary intake of the two groups. However, eating behaviors differed. Compared to the MHO group, the MAO women had a shorter meal time (less than 10 minutes), a preference of oily foods, and a tendency to eat until full. Therefore, the eating habits of MHO women were more positive than those of MAO women. CONCLUSIONS: The results suggest that fat distribution in each body region affects various metabolic abnormalities. A high level of arm fat mass in obese Korean women may increase metabolic risk. In addition, eating habits of obese Korean women are considered to be environmental factors affecting the metabolic phenotype of obese Korean women.
Absorptiometry, Photon ; Adipose Tissue ; Arm ; Basal Metabolism ; Body Composition ; Body Regions ; Calorimetry, Indirect ; Diet ; Eating ; Feeding Behavior ; Female ; Humans ; Meals ; Methyltestosterone ; Monoamine Oxidase ; Obesity ; Phenotype ; Respiratory Rate

AIMTo investigate the effects of total lactones of ginkgo on aging by using D-galactose induced aging mice and natural aging mice.

METHODSBy using D-galactose induced aging mice, to detect the LF content in heart and liver, the Hyp content in liver, the MAO, GSH-Px activities and the NO content in cerebrum. The apoptosis of cerebral cell was determined by terminal deoxy-nucleotidyl transforase-mediated dUTP-digoxigenin nick end-labeling (Tunel) in natural aging mice.

RESULTSTLG was shown to increase the GSH-Px activities, reduce the NO content and decrease the MAO activity in cerebrum. Meanwhile, TLG was found to reduce the LF content in liver and heart and raise the Hyp content in liver. TLG was shown to inhibit apoptosis of cerebral cell and decrease the number of apoptotic cells in the brain.

CONCLUSIONTLG possesses effect on antiaging via attenuating lipid peroxidation and NO and apoptosis of cerebral cells.

Aging ; metabolism ; Animals ; Apoptosis ; drug effects ; Female ; Galactose ; Ginkgo biloba ; chemistry ; Glutathione Peroxidase ; metabolism ; Hydroxyproline ; metabolism ; Lactones ; isolation & purification ; pharmacology ; Lipofuscin ; metabolism ; Liver ; metabolism ; Male ; Mice ; Monoamine Oxidase ; metabolism ; Myocardium ; metabolism ; Nitric Oxide ; metabolism ; Plants, Medicinal ; chemistry ; Telencephalon ; enzymology ; metabolism