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Query: UMLS:C0011570 (
depression
)
172,036
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The actions of NO synthase inhibitors and indomethacin, a cyclooxygenase inhibitor, on the nonadrenergic noncholinergic (NANC) mechanical responses of cat distal colon were studied in vitro using muscle strips orientated in the axis of the longitudinal muscle layer with pelvic nerves attached. Electrical field stimulation (EFS) or pelvic nerve stimulation (PNS) caused inhibition of spontaneous contractions followed by off-contractions. Indomethacin (10-30 microM) caused concentration-dependent reductions in amplitude and duration of EFS- and PNS-evoked off-contractions but not latency. The NO synthase inhibitors, N omega-nitro-L-arginine (L-NNA), N omega-nitro-L-arginine methyl ester (L-NAME) and NG-monomethyl-L-arginine (L-NMMA) (each at 100 microM) significantly reduced latency, amplitude, and duration of off-contractions evoked by EFS and PNS. This inhibition was partially reversed by L-arginine (120 microM) but not by D-arginine. Incubation of colonic strips with alpha-chymotrypsin (2 U/ml) decreased latency, amplitude, and duration of NANC off-contractions. L-NNA reduced amplitude, duration, and latency of off-contractions in preparations pretreated with alpha-chymotrypsin. Hydroquinone (10-30 microM), a generator of superoxide anions, caused significant
depression
of amplitude, duration, and latency of off-contractions which was completely reversed by
superoxide dismutase
(200 U/ml). These data suggest that the components of NANC off-contractions evoked by EFS and PNS involve peptides, NO, and prostaglandins.
...
PMID:A nitric oxide and prostaglandin-dependent component of NANC off-contractions in cat colon. 750 99
Patients with aplastic anemia were tested for natural killer (NK) activity, and the roles of granulocytes and granulocyte colony-stimulating factor (G-CSF) in the regulation of cytotoxicity were evaluated. Blood lymphocytes showed low or no NK activity against K562 targets. The
depression
of NK activity was more frequently recorded for patients who were not in remission and those who received G-CSF administration. Granulocytes of aplastic anemia patients with impaired NK activity suppressed the lytic activity of NK cells. By contrast, granulocytes from normal controls and aplastic anemia patients with normal NK activity had no suppressive activity. There was a good correlation between NK activity of lymphocytes and suppressive activity of granulocytes. Blocking of direct contact of suppressor and effector cells by cell chambers abolished suppression of cytotoxicity. NK suppression by granulocytes was resistant to treatment with catalase or
superoxide dismutase
. In vitro stimulation with G-CSF of granulocytes that naturally had no suppressive activity resulted in development of suppressive function, whereas granulocytes with natural suppressive activity were not further stimulated in vitro by G-CSF to express augmented activity. These results suggest that the presence of suppressor granulocytes in the blood could be one cause of the impaired NK activity in patients with aplastic anemia.
...
PMID:Suppression of natural killer cell activity by granulocytes in patients with aplastic anemia: role of granulocyte colony-stimulating factor. 751 63
We studied the action of H2O2 on the exocytosis of glutamate by cerebrocortical synaptosomes. The treatment of synaptosomes with H2O2 (50-150 microM) for a few minutes results in a long-lasting
depression
of the Ca(2+)-dependent exocytosis of glutamate, induced by KCl or by the K(+)-channel inhibitor 4-aminopyridine. The energy state of synaptosomes, as judged by the level of phosphocreatine and the ATP/ADP ratio, was not affected by H2O2, although a transient decrease was observed after the treatment. H2O2 did not promote peroxidation, as judged by the formation of malondialdehyde. In indo-1-loaded synaptosomes, the treatment with H2O2 did not modify significantly the KCl-induced increase of [Ca2+]i. H2O2 inhibited exocytosis also when the latter was induced by increasing [Ca2+]i with the Ca2+ ionophore ionomycin. The effects of H2O2 were unchanged in the presence of
superoxide dismutase
and the presence of the Fe3+ chelator deferoxamine. These results appear to indicate that H2O2, apparently without damaging the synaptosomes, induces a long-lasting inhibition of the exocytosis of glutamate by acting directly on the exocytotic process.
...
PMID:Hydrogen peroxide induces a long-lasting inhibition of the Ca(2+)-dependent glutamate release in cerebrocortical synaptosomes without interfering with cytosolic Ca2+. 776 35
Sevoflurane is well known to cause
depression
of cardiovascular function, but detailed information on its actions on the contractility and reactivity of blood vessels is lacking. We have assessed therefore the direct effect of this anaesthetic on the functional reactivity of isolated rabbit mesenteric artery ring preparations. We found that contractions of endothelium intact rings induced by noradrenaline and phenylephrine were significantly attenuated by 4% sevoflurane; the observation that the maximal tension generation decreased without a significant reduction in pD2 is consistent with the view that receptor dysfunction was not involved. The effect of sevoflurane was not affected by NG-monomethyl-L-arginine. Sevoflurane 4% also produced attenuation of noradrenaline-induced contractions of endothelium denuded ring preparations. The contractions of endothelium denuded ring preparations produced by noradrenaline in Ca(2+)-free media in the presence of K+ were not affected by 4% sevoflurane, but sevoflurane depressed external Ca(2+)-dependent contractions. When vasodilators (acetylcholine and nitroglycerin) were added to the bathing media in the presence of 2% sevoflurane, the endothelium-dependent relaxation produced by acetylcholine, but not the endothelium-independent relaxation produced by nitroglycerin, was attenuated;
superoxide dismutase
inhibited the effect of sevoflurane on endothelium-dependent relaxation. These results are consistent with the view that sevoflurane inhibits alpha adrenoceptor-mediated contractions of isolated rabbit mesenteric artery ring preparations; this effect may be caused by reduced Ca2+ influx, as estimated from the effect on external Ca(2+)-dependent contractions, but is unlikely to be caused by reduced Ca2+ release from the sarcoplasmic reticulum of vascular smooth muscle, as estimated from noradrenaline-induced contractions in Ca(2+)-free bathing media.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Effect of sevoflurane on the vascular reactivity of rabbit mesenteric artery. 777 35
We investigated the effects of hemorrhagic shock and reinfusion on the cardiac function and contractility, plasma CK and CK-MB activity and lactate concentration, oxyradical-producing activity of polymorphonuclear leukocytes (PMNL-CL), cardiac chemiluminescence (LV-CL), antioxidant enzymatic activity [
superoxide dismutase
(
SOD
), catalase, glutathione peroxidase (GSH-Px)], and malondialdehyde (MDA) concentration in anesthetized dogs, to determine the role of oxyradicals in cardiac
depression
and cellular injury in hemorrhagic shock and reinfusion. The dogs were assigned to four groups: group I (sham), 4 hrs duration; group II, 4 hr of shock; group III, 2 hr of shock, followed by reinfusion for 2 hr; and group IV, as in group III, but pretreated with
SOD
and catalase. Hemorrhagic shock was produced by withdrawing blood to maintain the mean arterial pressure at 50 +/- 5 mm Hg. Cardiac function and contractility were depressed during hemorrhagic shock. Plasma CK; CK-MB and lactate; and cardiac MDA, Mn-SOD, and CuZn-
SOD
increased, while catalase activity decreased during shock. Following reinfusion after 2 hr of shock, hemodynamic parameters and plasma lactate tended to return toward control values. Plasma CK and CK-MB, PMNL-CL and cardiac MDA, total
SOD
, Mn- and CuZn-
SOD
increased further, while LV-CL and GSH-Px decreased. In spite of the increased antioxidant reserve, oxidative damage was noted. Pretreatment with
SOD
and catalase attenuated the deleterious effects of shock and reinfusion on the cardiovascular function, plasma CK, CK-MB, and lactate, PMNL-CL, cardiac MDA and
SOD
, and LV-CL. Protection was incomplete for cardiovascular function and plasma CK and CK-MB. These results suggest that oxyradicals (O2-, H2O2) may be partly involved in the deterioration of cardiovascular function and cellular injury during hemorrhagic shock and reinfusion.
...
PMID:Role of oxyradicals in cardiovascular depression and cellular injury in hemorrhagic shock and reinfusion: effect of SOD and catalase. 783 24
In the olfactory-bulbectomised rat model of
depression
, neutrophil phagocytosis was significantly decreased and phagocytosis started later in comparison to sham-operated animals. Both desipramine and lithium chloride treatment significantly reversed the depressed neutrophil phagocytosis and shortened the time to commencement of phagocytosis in drug-treated bulbectomised rats. The catalase and glutathione peroxidase (GSH-PX) activities in bulbectomised rats were decreased, while
superoxide dismutase
(
SOD
) was significantly increased. Chronic desipramine and lithium chloride treatment slightly improved catalase activity in the bulbectomised rats. Desipramine significantly reversed the reduction in activity of GSH-PX, but failed to reverse the increased activity of
SOD
. In contrast, lithium chloride significantly reversed
SOD
activity to normal values, without affecting GSH-PX activity in the bulbectomised rats.
...
PMID:Catalase, superoxide dismutase and glutathione peroxidase activity in neutrophils of sham-operated and olfactory-bulbectomised rats following chronic treatment with desipramine and lithium chloride. 796 55
In this study, we separated the effects of low oxygen supply and low coronary flow in isolated perfused rat hearts to focus on the genesis of free radicals-induced reperfusion injury. Hearts were exposed to either hypoxemia/reoxygenation or ischemia/reperfusion in various sequences, with hypoxemia and ischemia matched for duration (20 min), temperature (37 degrees C), and oxygen supply (10% of baseline). Hypoxemia/reoxygenation (n = 7) resulted in lower (developed pressure) x (heart rate) (p < 0.001) and higher end-diastolic pressure (p < 0.001) than ischemia/reperfusion (n = 9). The presence of 40 IU/ml
superoxide dismutase
and 104 IU/ml catalase nearly blunted the rise of the end-diastolic pressure (p = 0.02 vs. baseline), but could only partially prevent the
depression
of myocardial contractility (p < 0.001 vs. baseline, n = 7). Similar patterns were observed when hearts were made ischemic after hypoxemia, eliminating the intermediate reoxygenation step. We conclude that the major determinant of the reperfusion injury is associated with low oxygen supply rather than low coronary flow. Part of the injury is mediated by oxygen-derived free radicals, but a substantial portion of it is associated with energetic processes.
...
PMID:Oxidative injury in reoxygenated and reperfused hearts. 800 21
The vasodilator action of the isopropyl ester of palmitoyl carnitine (P1Pi) has been examined in perfused rat hearts and mesenteric vessels. The coronary vasodilator effect P1Pi was not significantly inhibited by flurbiprofen (10 microM), BW755C (10 microM), glibenclamide (10 microM) or the bradykinin B2 receptor antagonist D-Arg0[Hyp3,Thi5,8,D-Phe7]bradykinin (1 microM), indicating that the action of P1Pi is not mediated via arachidonic acid metabolites, ATP-dependent K+ channels or bradykinin B2 receptors. L-NG-Nitro arginine (100 microM) did not inhibit the vasodilator action of P1Pi whilst
superoxide dismutase
(20 and 50 U.ml-1) attenuated its vasodilator action. Methylene blue (10 microM) caused inhibition in three out of four hearts, while haemoglobin (1 microM) caused an irreversible inhibition of the action of P1Pi which was associated with a
depression
of myocardial contractility. In air-damaged mesenteric vascular beds the vasodilator action of P1Pi was not attenuated, whilst that of acetylcholine was abolished. In K(+)-depolarised mesenteric vascular beds the constrictor action of Ca2+ was attenuated by P1Pi. Therefore the vasodilator effect of P1Pi appears to be the result of a direct effect on smooth muscle.
...
PMID:Vasodilator action of the isopropyl ester of palmitoyl carnitine in the rat coronary circulation and mesenteric vascular bed. 802 46
Rats (Wistar, female, 4 weeks old) were fed iron-deficient (Fe-; 2.2 micrograms Fe/g) or manganese- and copper-deficient (Mn.Cu-; 0.3 microgram Mn/g, 0.4 microgram Cu/g) diets for 8 weeks to determine the oxidative damage of DNA by element deficiency. After feeding of the diets, 2-nitropropane (2-NP, 80 mg/kg body weight) was administered i.p. as an inducer of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) to the element-deficient rats. The hemoglobin concentration of rats in the Fe- group showed an induction of severe anemia (8.4 g/100 ml whole blood). In the Mn.Cu- group, Mn-
superoxide dismutase
(
SOD
) activities of plasma and Cu.Zn-
SOD
activities were significantly lower than that of the normal diet group. However, total
SOD
activities of plasma were not depressed severely in contrast to that of the liver in the Mn.Cu- group. Background (spontaneous) levels of 8-OH-dG in normal diet group were 0.96 +/- 0.37/10(5) deoxyguanosine (dG), however, significantly higher levels were detected in the Fe- group (1.56 +/- 0.19, P < 0.01). Conversely, a lower (but not significant) level of 8-OH-dG than the normal diet group were detected in the Mn.Cu- group (0.78 +/- 0.08). Six hours after 2-NP treatment, 8-OH-dG levels in liver DNA were significantly induced to 1.44 +/- 0.24 in the normal diet fed group 1.89 +/- 0.22 in the Fe- and 1.08 +/- 0.12 in the Mn.Cu- groups. Compared to the normal diet group, these induced levels of 8-OH-dG in the Fe- group were significantly higher (P < 0.05), and that in Mn.Cu- group were significantly lower (P < 0.05). The high level of 8-OH-dG in severe iron deficiency might be the results of: (i) an increase of hydroxyl radical generation by accumulated copper in hepatocytes; or (ii), a
depression
of enzymatic activity for removing 8-hydroxy-2'-deoxyguanosine in DNA, which is dependent on divalent cations. On the other hand, the low level of 8-OH-dG in manganese and copper deficiency might be the result of a decrease of lipid peroxidation which has been suggested to be an intermediator from active oxygen species to hydroxyl radical.
...
PMID:Spontaneous and 2-nitropropane induced levels of 8-hydroxy-2'-deoxyguanosine in liver DNA of rats fed iron-deficient or manganese- and copper-deficient diets. 838 15
To understand the mechanism for the expulsion of Nippostrongylus brasiliensis from rats, age-dependent variations in the metabolism of reactive oxygen species in the parasite and the host intestines were examined. N. brasiliensis showed an age-dependent increase in its susceptibility to xanthine-xanthine oxidase and t-butyl hydroperoxide generated oxidants as well as to H2O2. Protection obtained with several scavengers suggested that the worms were damaged by the combined action of oxidants generated by the in vitro systems employed. The level of
superoxide dismutase
in the nematode and its release into the surroundings exhibited a marked
depression
with advancement of age. No such alteration was, however, recorded for catalase and glutathione peroxidase. An appreciable decrease in the level of reduced glutathione in older N. brasiliensis appears to render them prone to oxidant attack. The rat intestines, on the other hand, exhibited an appreciable
depression
in catalase and a reduced glutathione content with progress of the infection. Vitamin E levels were elevated. The release of O2-. and H2O2 by the intestines was also found to be greater during later stages of the infection. The combined effect of the changes observed in N. brasiliensis and in the rat intestines may be at least partly responsible for expulsion of the nematode from the rats after day 10.
...
PMID:Role of reactive oxygen species in expulsion of Nippostrongylus brasiliensis from rats. 838 14
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