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1.
Auton Neurosci ; 197: 25-33, 2016 05.
Article in English | MEDLINE | ID: mdl-27189100

ABSTRACT

Diabetes mellitus (DM) determines a wide array of severe clinical complications including gastrointestinal motility disorders. The present study investigates the effects of spontaneous DM on the intramural innervation and in particular on nitrergic neurons of the myenteric plexus (MP) of the canine gastric antrum and ileum. Specimens of antrum and ileum from eight control-dogs and five insulin-dependent DM-dogs were collected. MP neurons were immunohistochemically identified with the anti-HuC/HuD antibody, while nitrergic neurons were identified with the antibody anti-neuronal nitric oxide synthase (nNOS). The density of HuC/HuD-immunoreactive (IR) neurons was determined and the nitrergic neurons were quantified as a relative percentage, in consideration of the total number of HuC/HuD-IR neurons. Furthermore, the density of nitrergic fibers in the muscular layers was calculated. Data were expressed as mean±standard deviation. Compared to control-dogs, no significant differences resulted in the density of HuC/HuD-IR neurons in the antrum and ileum of DM-dogs; however, HuC/HuD-immunolabeling showed nuclear localization and fragmentation in DM-dogs. In the stomachs of control- and DM-dogs, the percentages of nitrergic neurons were 30±6% and 25±2%, respectively (P=0.112). In the ileum of the control-dogs, the percentage of nitrergic neurons was 29±5%, while in the DM-dogs, it was significantly reduced 19±5% (P=0.006). The density of nNOS-IR nervous fibers was meaningful reduced in either the tracts considered. Notably, the ganglia of DM-dogs showed also a thickening of the periganglionic connective tissue. These findings indicate that DM in dogs induce modification of the myenteric neurons and, in particular, of the nitrergic neuronal subpopulation.


Subject(s)
Diabetes Mellitus, Experimental/metabolism , Ileum/innervation , Neurons/metabolism , Nitrergic Neurons/metabolism , Nitric Oxide Synthase Type I/metabolism , Pyloric Antrum/metabolism , Stomach/innervation , Animals , Diabetes Mellitus, Experimental/physiopathology , Dogs , Immunohistochemistry/methods , Myenteric Plexus/drug effects , Myenteric Plexus/metabolism
2.
Biochim Biophys Acta ; 970(2): 113-21, 1988 Jun 30.
Article in English | MEDLINE | ID: mdl-3382695

ABSTRACT

Experiments were performed to investigate the effects of 60 min severe global ischemia followed by 30 min reperfusion on the antioxidant enzymatic system in the isolated perfused rat heart. Ischemia induced a significant increase of cytoplasmic and mitochondrial selenium-dependent glutathione peroxidase (EC 1.11.1.9) activity. In reperfused hearts, only the mitochondrial form showed a further significant increase. Glutathione reductase (EC 1.6.4.2) was increased in ischemic hearts, whilst the reperfused hearts showed a decrease towards the level found in aerobic hearts. Mitochondrial superoxide dismutase (EC 1.15.1.1) activity was depressed in ischemic as well as in reperfused hearts, though the cytoplasmic form was unmodified. Catalase (EC 1.11.1.6), glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and glutathione transferase (EC 2.5.1.18) activities were unchanged throughout the experiment. Ischemia and reperfusion induced a significant fall in tissue-reduced glutathione content concomitant with an increase of its oxidized form. We have also studied the mitochondrial inner membrane proteins for both molecular weight, with Coomassie blue, and thiol status, with monobromobimane stain, using a sodium dodecyl sulfate polyacrylamide gel electrophoresis technique. Neither ischemia nor reperfusion effected any relevant modification of the molecular weight of the mitochondrial inner-membrane proteins either in the presence or absence of a reducing agent. However, two of these proteins with an apparent molecular weight of 52,0000 and 12,000 showed a decrease in the monobromobimane stain, probably due to the oxidation of their thiol groups.


Subject(s)
Antioxidants , Coronary Disease/enzymology , Glutathione Peroxidase/metabolism , Membrane Proteins/metabolism , Mitochondria, Heart/enzymology , Myocardium/enzymology , Perfusion , Animals , Electrophoresis, Polyacrylamide Gel , Free Radicals , Glutathione/analogs & derivatives , Glutathione/metabolism , Glutathione Disulfide , Intracellular Membranes/enzymology , Intracellular Membranes/metabolism , Male , Mitochondria, Heart/metabolism , Myocardium/metabolism , Rats , Rats, Inbred Strains
3.
Clin Physiol Biochem ; 6(6): 327-33, 1988.
Article in English | MEDLINE | ID: mdl-3208485

ABSTRACT

We studied the plasma concentration of various amino acids in 6 Italian sport divers in Italy and at approximately 4,500 m altitude in Peru; 6 Peruvian inhabitants were examined for comparison. We attempted to create a situation of pronounced hypoxia in muscles by breath-hold diving at altitude. The diving reflex diverts blood away from muscles while diving increases central oxygen tension and prevents loss of consciousness. Differences in certain amino acids, probably related to diet, were noted between Italy and Peru. Increases in concentration of plasma alanine and some branched-chain amino acids occurred after breath-hold diving. These changes were similar to those seen after prolonged hard exercise, even though physical work was low. Hypoxia in muscles, common during hard work and during breath-hold diving at altitude, might thus be the stimulus for amino acid release from working muscles.


Subject(s)
Amino Acids/blood , Diving , Adult , Altitude , Anaerobiosis , Dietary Proteins/administration & dosage , Humans , Hypoxia/blood , Lactates/blood , Lactic Acid , Muscles/metabolism , Urea/blood
4.
Placenta ; 7(2): 155-62, 1986.
Article in English | MEDLINE | ID: mdl-3725746

ABSTRACT

Glutathione S-transferase activity significantly decreased in the rat placenta from the 16th to the 20th day of gestation. Isoelectric focusing of rat placenta supernatant yielded essentially a single peak of glutathione S-transferase activity with I-chloro-2,4-dinitrobenzene as substrate, centred on pH 7.45. Substrate specificity measurements, as well as inhibitory studies, revealed pronounced differences between rat and human placental enzymes. Whether the biochemical differences between rat and human GSH-Trs are reflected in physiological differences remains to be ascertained. The sodium dodecyl sulphate (SDS) gel electrophoresis data on subunit composition showed that the rat enzyme is composed of two identical subunits whose molecular mass closely approaches that of human transferase.


Subject(s)
Glutathione Transferase/analysis , Placenta/enzymology , Animals , Female , Humans , Hydrogen-Ion Concentration , Kinetics , Molecular Weight , Pregnancy , Rats , Rats, Inbred Strains , Species Specificity
5.
Experientia ; 41(1): 66-7, 1985 Jan 15.
Article in English | MEDLINE | ID: mdl-2857128

ABSTRACT

The levels of GSH-related enzyme activities during pregnancy were determined. A significant increase in Selenium-dependent GSH peroxidase and GSH S-transferase E activity was observed. A concomitant increase in gamma-glutamylcysteine synthetase was measured, which indicated an increased ability to synthesize the tripeptide.


Subject(s)
Glutathione/metabolism , Liver/enzymology , Pregnancy, Animal , Animals , Female , Glutamate-Cysteine Ligase/metabolism , Glutathione Peroxidase/metabolism , Glutathione Transferase/metabolism , Isoenzymes/metabolism , Pregnancy , Rats , Rats, Inbred Strains , Selenium/pharmacology , Substrate Specificity
6.
Int J Biochem ; 17(5): 653-6, 1985.
Article in English | MEDLINE | ID: mdl-4029484

ABSTRACT

Glutathione S-transferase activity from human platelets was purified to homogeneity by affinity chromatography. The purified enzyme was found to be the acidic form and its molecular and catalytic properties were identical to acidic glutathione S-transferases purified from other human tissues. The purified platelet enzyme had no peroxidase activity and did not protect microsomes against peroxidation.


Subject(s)
Blood Platelets/enzymology , Glutathione Transferase/blood , Amino Acids/analysis , Chromatography, Affinity , Electrophoresis, Polyacrylamide Gel , Humans , Kinetics , Peroxides/blood
7.
Res Commun Chem Pathol Pharmacol ; 46(3): 411-23, 1984 Dec.
Article in English | MEDLINE | ID: mdl-6515130

ABSTRACT

Human purified placenta GSH S-transferase was generally inhibited by penicillins and cephalosporins to a different extent. Among the seven penicillins tested the dihalogenate dicloxacillin and flucloxacillin were the strongest inhibitors. All cephalosporins showed competitive inhibition for the electrophilic substrate, while penicillins acted as non-competitive inhibitors. Exposure of the enzyme to cephalosporins led to the loss of the catalytic activity. Addition of reduced glutathione in the incubation system would induce the formation of a conformational state of the enzyme which prevents cephalosporins binding.


Subject(s)
Cephalosporins/pharmacology , Glutathione Transferase/antagonists & inhibitors , Penicillins/pharmacology , Placenta/enzymology , Female , Humans , In Vitro Techniques , Kinetics , Pregnancy
8.
Int J Biochem ; 16(7): 741-6, 1984.
Article in English | MEDLINE | ID: mdl-6468734

ABSTRACT

Specific activities of GSH S-transferase toward different model substrates were determined in the cytosol prepared from rat, guinea pig, rabbit, mouse, sheep, beef, pig and human brain cortex. The GSH S-transferase composition of the eight mammalian brain cortices was studied by using density gradient isoelectric focusing technique. Human brain cortex GSH S-transferase was resolved into a single peak of activity centered at pH 4.6, whereas the supernatants of all other mammals consisted of more than one enzymatic form. The kinetic properties of all forms isolated were compared.


Subject(s)
Cerebral Cortex/enzymology , Glutathione Transferase/isolation & purification , Polymorphism, Genetic , Adult , Animals , Brain Neoplasms/enzymology , Cytosol/enzymology , Glutathione Transferase/genetics , Guinea Pigs , Humans , Mice , Rabbits , Rats , Sheep , Species Specificity , Swine
9.
Int J Biochem ; 16(5): 505-9, 1984.
Article in English | MEDLINE | ID: mdl-6724105

ABSTRACT

Superoxide dismutase, reduced glutathione and lipid peroxides levels were determined in the erythrocytes of multiple sclerosis patients. Superoxide dismutase activity and the malonyldialdehyde production rate were found to be significantly enhanced. The isoelectric focusing pattern of superoxide dismutase from multiple sclerosis and normal subjects erythrocytes was substantially overlapping. Our results indicate the occurrence of a higher susceptibility of multiple sclerosis erythrocytes to lipid peroxidation.


Subject(s)
Erythrocytes/metabolism , Glutathione/blood , Lipid Peroxides/blood , Multiple Sclerosis/metabolism , Superoxide Dismutase/blood , Humans , Malondialdehyde/blood , Thiobarbiturates/pharmacology
10.
Biochem Med ; 29(2): 143-8, 1983 Apr.
Article in English | MEDLINE | ID: mdl-6134525

ABSTRACT

GSH peroxidase, GSSG reductase, GSH S-transferase, and gamma-glutamyltranspeptidase activities were measured in the supernatant of 13 human early pregnancy placenta homogenates. From measurements of GSH peroxidase activity with both H2O2 and cumene hydroperoxide as second substrate it was deduced that immature placenta contains only the Se-dependent form. All the specimens investigated exhibited GSSG reductase and gamma-glutamyltranspeptidase activities. GSH S-transferase activity was noted only using 1-chloro-2,4-dinitrobenzene as electrophilic substrate, while no detectable activity was found with 1,2-dichloro-4-nitrobenzene, 1,2-epoxy-3-(p-nitrophenoxy) propane, and p-nitrobenzylchloride. It is concluded that human placenta is equipped, from early pregnancy, with the enzymatic systems which are involved in GSH-mediated cellular detoxication and in preserving the integrity of the sulfhydryl status of the cells.


Subject(s)
Glutathione Peroxidase/metabolism , Glutathione Reductase/metabolism , Glutathione Transferase/metabolism , Peroxidases/metabolism , Placenta/enzymology , gamma-Glutamyltransferase/metabolism , Female , Humans , Pregnancy , Pregnancy Trimester, First
11.
Gen Pharmacol ; 13(6): 485-90, 1982.
Article in English | MEDLINE | ID: mdl-6818096

ABSTRACT

1. Specific activities of glutathione S-transferase towards four model substrates were determined in guinea-pig brain 50,000 g supernatant and compared with those obtained for liver and kidney extract. 2. By using 1-chloro-2,4-dinitrobenzene as substrate, glutathione S-transferase activity was measured in different anatomical regions of brain; cerebellum expressed the highest conjugating capacity. 3. Brain glutathione S-transferase was resolved into four major peaks (PI 6.10, 6.60, 7.15, 7.65) each having similar kinetic constants for both substrates GSH and 1-chloro-2,4-dinitrobenzene. 4. Likewise, four forms, focused at pH 6.45, 7.14, 7.50 and 8.88, were obtained from liver. 5. Unlike hepatic tissue, brain does not possess the highly alkaline form which displays Se-independent GSH peroxidase activity. 6. Several psychotropic agents, including chlorpromazine and chlorazepate, produced a considerable in vitro inhibition on brain transferase activity.


Subject(s)
Brain/enzymology , Glutathione Transferase/metabolism , Liver/enzymology , Animals , Chromatography, Gel , Cytosol/enzymology , Female , Glutathione Transferase/antagonists & inhibitors , Guinea Pigs , Immunodiffusion , In Vitro Techniques , Isoelectric Focusing , Isoenzymes/metabolism , Kinetics , Psychotropic Drugs/pharmacology
15.
Boll Soc Ital Biol Sper ; 55(22): 2346-50, 1979 Nov 30.
Article in Italian | MEDLINE | ID: mdl-549600

ABSTRACT

The riductive scission of a diselenide (selenocystamine) produced by disulfide gives the perselenosulfide, a new compound. Its formation kinetics, carried out a several pH values, were recorded spectrophotometrically at 375 nm. The lability of perselenosulfide bond by cianolysis has been demonstrated.


Subject(s)
Selenium/analysis , Spectrophotometry , Sulfides/analysis
16.
Boll Soc Ital Biol Sper ; 55(9): 840-3, 1979 May 15.
Article in Italian | MEDLINE | ID: mdl-553608

ABSTRACT

Glutathione-S-transferase activity has been identified in the cytosol of human placenta. The specific activity measured is about 50% of that found in human liver. While some kinetic data have a close correspondence with those attributed to transferases of other sources, the molecular weight (60.000 daltons) and electric properties of this protein are unusual. The inhibitory effect of several non-substrate compounds suggests that also the placental Glutathione-S-transferase may play some role in detoxication of exogenous substances.


Subject(s)
Glutathione Transferase/physiology , Placenta/enzymology , Cephaloridine/pharmacology , Female , Glutathione/metabolism , Glutathione Transferase/antagonists & inhibitors , Humans , Liver/enzymology , Molecular Weight , Pregnancy , Rose Bengal/pharmacology , Sulfobromophthalein/pharmacology , Temperature
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