Diethyldithiocarbamate, a superoxide dismutase inhibitor, counteracts the maturation of ischemic-like lesions caused by endothelin-1 intrastriatal injection

The effect of sodium alginate on the immune response of tiger shrimp via dietary administration: activity and gene transcription

The total haemocyte count (THC), phenoloxidase (PO) activity, respiratory bursts (release of superoxide anions), and superoxide dismutase (SOD) activity, as well as expressions of beta-1,3-glucan-binding protein (betaGBP), prophenoloxidase (proPO), peroxinectin (PE), cytosolic SOD (cyt-SOD), penaeidin-5 (PA-5), and a single whey acidic protein (WAP) domain protein (SWDP) gene were determined in the tiger shrimp Penaeus monodon (15.6-19.5g) which had individually been fed diets containing sodium alginate at 0, 1.0, or 2.0gkg(-1) for 5months. Results showed that shrimp fed a diet containing 1.0 and 2.0gkg(-1) sodium alginate had significantly increased SOD activity but decreased respiratory bursts. The expressions of betaGBP, PE, cyt-SOD, PA-5, and SWDP were significantly elevated in shrimp fed the Collapse

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MESH Headings

• Alginates/administration & dosage
• Alginates/pharmacology
• Animals
• DNA Primers/chemistry
• Diet
• Gene Expression/drug effects
• Glucuronic Acid/administration & dosage
• Glucuronic Acid/pharmacology
• Hexuronic Acids/administration & dosage
• Hexuronic Acids/pharmacology
• Monophenol Monooxygenase/drug effects
• Monophenol Monooxygenase/metabolism
• Penaeidae/drug effects
• Penaeidae/genetics
• Penaeidae/immunology
• Phaeophyceae/chemistry
• Proteins/analysis
• Respiratory Burst/drug effects
• Reverse Transcriptase Polymerase Chain Reaction/methods
• Superoxide Dismutase/drug effects
• Superoxide Dismutase/metabolism

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Affiliation(s)

Chun-Hung Liu Department of Aquaculture, National Pingtung University of Science and Technology, Pingtung, Taiwan 91201, PR China
Shinn-Pyng Yeh
Chin-Ming Kuo
Winton Cheng
Chang-Hung Chou

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Noradrenaline modulates the immunity of white shrimp Litopenaeus vannamei

The total haemocyte count (THC), phenoloxidase activity, respiratory burst, superoxide dismutase (SOD) activity, phagocytic activity and clearance efficiency in response to pathogen Vibrio alginolyticus were measured when the white shrimp Litopenaeus vannamei (18.4 +/- 1.2 g) were injected individually with noradrenaline at 10(-8), 10(-7) and 10(-6) mol shrimp(-1). For the shrimp that received noradrenaline at 10(-8), 10(-7) and 10(-6) mol shrimp(-1), the THC decreased by 15%, 21% and 32%, phenoloxidase activity decreased by 15%, 31% and 31%, respiratory burst decreased by 13%, 21% and 32%, and SOD activity decreased by 46%, 56% and 55%, respectively, after 2 h. The phagocytic activity and clearance efficiency of shrimp that received noradrenaline at either dose decreased significantly after 2 h. The THC, phenoloxidase activity, respiratory burst, SOD activity, phagocytic activity and clearance efficiency returned to normal values after 4, 4, 8, 24, 16 and 8 h, respectively, in the shrimp that received noradrenaline at either dose. In another experiment, L. vannamei which had received noradrenaline at 10(-8), 10(-7) and 10(-6) mol shrimp(-1) were challenged after 1h by injection with V. alginolyticus at 1.0 x 10(5) colony-forming units (cfu)shrimp(-1) and then placed in seawater of 20 per thousand. The cumulative mortality of shrimp that received noradrenaline at either dose was significantly higher than that of shrimp that received saline after 4 h, and at the termination of the experiment (48 h after the challenge). It is therefore concluded that noradrenaline administration at 10(-6) mol shrimp(-1) or less causes immune modulation of L. vannamei.

Endogenous neurosteroids modulate epileptogenesis in a model of temporal lobe epilepsy

Neurosteroids modulate seizure susceptibility, but their role in the regulation of epileptogenesis is unknown. Status epilepticus (SE) induces temporal lobe epileptogenesis following a latent period in which glial cells are activated. Here, we found that P450scc, the rate-limiting enzyme in steroid synthesis, is upregulated in hippocampal glia during the latent period after pilocarpine-induced SE in rats. More prolonged SE was associated with greater P450scc expression and longer latencies to the development of seizures, suggesting that enhanced steroid synthesis retards epileptogenesis. The 5alpha-reductase inhibitor finasteride, which blocks neurosteroid synthesis, reduced the latent period, indicating that glia-derived neurosteroids may be antiepileptogenic.

Trichlorfon, an organophosphorus insecticide, depresses the immune responses and resistance to Lactococcus garvieae of the giant freshwater prawn Macrobrachium rosenbergii

The total haemocyte count (THC), phenoloxidase activity, respiratory bursts (release of superoxide anions), superoxide dismutase (SOD) activity, and phagocytic activity and clearance efficiency to the pathogen Lactococcus garvieae were measured when freshwater giant prawns Macrobrachium rosenbergii (18.2+/-2.1 g) were individually reared in water containing concentrations of trichlorfon of 0, 0.2, or 0.4 mg L(-1) for a 144-h period. No significant differences in the THC were observed among prawns at the beginning and following 144 h of exposure to 0, 0.2, and 0.4 mg L(-1) trichlorfon. However, phenoloxidase activity significantly decreased when the prawns were exposed to trichlorfon at 0.2 and 0.4 mg L(-1), and no significant differences were observed between the two concentrations at any sampling time. The total production of superoxide anion by M. rosenbergii significantly increased with exposure to 0.2 and 0.4 mg L(-1) trichlorfon, and no significant differences were observed between the two concentrations during the 144-h exposure period. However, M. rosenbergii exposed to 0.2 and 0.4 mg L(-1) trichlorfon showed decreased SOD activity from 48 to 144 h. Phagocytic activity and clearance efficiency to L. garvieae significantly decreased when prawns were exposed to 0.2 and 0.4 mg L(-1) trichlorfon for 48 h. In another experiment, prawns were challenged with 5 x 10(5) colony-forming units (cfu)prawn(-1) of L. garvieae, then reared in water containing different concentrations of trichlorfon. The onset of mortality was earlier in prawns exposed to trichlorfon compared to those exposed to the zero control. The cumulative mortality of prawns directly increased with ambient trichlorfon concentrations in the range of 0-0.4 mg L(-1) after 168 h. It is concluded that exposure of M. rosenbergii to trichlorfon at 0.2 mg L(-1) or more caused cytotoxicity resulting in depression of the immune response, and increased its susceptibility to L. garvieae infection.

The protective effect of chitin and chitosan against Vibrio alginolyticus in white shrimp Litopenaeus vannamei

White shrimp, Litopenaeus vannamei, which had been injected with chitin at 4, 6 and 8 microg g(-1) or chitosan at 2, 4 and 6 microg g(-1), were challenged with pathogen Vibrio alginolyticus at 2 x 10(6) colony-forming units (cfu) shrimp(-1) and then placed in seawater of 34 per thousand. The survival of shrimp that received chitin or chitosan at either dose was significantly higher than that of control shrimp after 1 day, and at the termination of the experiment (6 days after the challenge). In another experiment, the total haemocyte count (THC), phenoloxidase activity, respiratory burst, superoxide dismutase (SOD) activity, and phagocytic activity to V. alginolyticus were measured when L. vannamei (10.4 +/- 0.7 g) were injected individually with chitin at 4 and 6 microg g(-1) or chitosan at 2 and 4 microg g(-1). L. vannamei received chitin at 6 microg g(-1) or chitosan at 2 and 4 microg g(-1) increased significantly its THC and respiratory burst after 2 days. L. vannamei received chitin at 6 microg g(-1) or chitosan at 2 and 4 microg g(-1) still maintained significantly higher phenoloxidase activity after 6 days. L. vannamei received chitin at 4 and 6 microg g(-1) or chitosan at 2 and 4 microg g(-1) increased its phagocytic activity against V. alginolyticus after 1 day, respectively. It is therefore concluded that L. vannamei that received chitin at 6 microg g(-1) or chitosan at 4 microg g(-1) or less increased its immune ability and resistance to V. alginolyticus infection.

Dopamine depresses the immune ability and increases susceptibility to Lactococcus garvieae in the freshwater giant prawn, Macrobrachium rosenbergii

The total haemocyte count (THC), phenoloxidase activity, respiratory burst (release of superoxide anion), superoxide dismutase activity, and phagocytic activity and clearance efficiency to the pathogen Lactococcus garvieae were measured when freshwater giant prawns Macrobrachium rosenbergii (16.2 +/- 2.1 g) were individually injected with saline, or dopamine at 0.5, 5.0, or 50.0 pmol prawn(-1). The results show that a transient period of immunosuppression occurred between 2 and 8 h after injection of dopamine for all immune parameters except circulating haemocytes and all immune parameters returned to control values within 8-16 h after receiving dopamine. Injection of dopamine also significantly increased the mortality of M. rosenbergii challenged with the pathogen L. garvieae. These results suggest that stress-inducing dopamine suppresses the immune system, which in turn promotes the susceptibility to L. garvieae in M. rosenbergii.

The immunostimulatory effect of hot-water extract of Gracilaria tenuistipitata on the white shrimp Litopenaeus vannamei and its resistance against Vibrio alginolyticus

The total haemocyte count (THC), phenoloxidase activity, respiratory burst, superoxide dismutase (SOD) activity, phagocytic activity and clearance efficiency to the pathogen Vibrio alginolyticus were examined in the white shrimp Litopenaeus vannamei (10.3+/-1.5 g) injected individually with hot-water extract of Gracilaria tenuistipitata at 4 or 6 microg g-1. L. vannamei receiving hot-water extract of G. tenuistipitata at either dose increased significantly its THC, phenoloxidase activity, and respiratory burst after 2 days. L. vannamei received hot-water extract of G. tenuistipitata at 6 microg g-1 increased its phagocytic activity and clearance efficiency to V. alginolyticus after 1 day. In another experiment, L. vannamei which had been injected with hot-water extract of G. tenuistipitata were challenged with V. alginolyticus at 2x10(6) colony-forming units (cfu) shrimp-1 and then placed in seawater of 34 per thousand. The survival of shrimp that received hot-water extract of G. tenuistipitata at 6 microg g-1 was significantly higher than that of shrimp that received saline and the control shrimp after 3 days, and at the termination of the experiment (6 days after the challenge). It is therefore concluded that L. vannamei receiving the hot-water extract of G. tenuistipitata at 6 microg g-1 or less increased its immune ability and resistance to V. alginolyticus infection.

Cardiac-specific blockade of NF-κB in cardiac pathophysiology: differences between acute and chronic stimuli in vivo

The role of NF-κB in cardiac physiology and pathophysiology has been difficult to delineate due to the inability to specifically block NF-κB signaling in the heart. Cardiac-specific transgenic models have recently been developed that repress NF-κB activation by preventing phosphorylation at specific serine residues of the inhibitory κB (IκB) protein isoform IκBα. However, these models are unable to completely block NF-κB because of a second signaling pathway that regulates NF-κB function via Tyr42 phosphorylation of IκBα. We report the development of transgenic (3M) mouse lines that express the mutant IκBα(S32A,S36A,Y42F)in a cardiac-specific manner. NF-κB activation in cardiomyopathic TNF-1.6 mice is completely blocked by the 3M transgene but only partially blocked (70–80%) by the previously described double-mutant 2M [IκBα(S32A,S36A)] transgene, which demonstrates the action of two proximal pathways for NF-κB activation in TNF-α-induced cardiomyopathy. In contrast, after acute stimuli including administration of TNF-α and ischemia-reperfusion (I/R), NF-κB activation is blocked in both 2M and 3M transgenic mice. This result suggests that phosphorylation of the regulatory Ser32 and Ser36 predominantly mediates NF-κB activation in these situations. We show that infarct size after I/R is reduced by 70% in 3M transgenic mice, which conclusively demonstrates that NF-κB is involved in I/R injury. In summary, we have engineered novel transgenic mice that allow us to distinguish two major proximal pathways for NF-κB activation. Our results demonstrate that the serine and tyrosine phosphorylation pathways are differentially activated during different pathophysiological processes (cardiomyopathy and I/R injury) and that NF-κB contributes to infarct development after I/R.

Dietary administration of sodium alginate enhances the immune ability of white shrimp Litopenaeus vannamei and its resistance against Vibrio alginolyticus

Haemocyte count, phenoloxidase activity, respiratory burst (release of superoxide anion), superoxide dismutase (SOD) activity, glutathione peroxidase (GPX) activity, phagocytic activity and clearance efficiency to the pathogen Vibrio alginolyticus were measured in white shrimp Litopenaeus vannamei juveniles (12.3 +/- 1.2 g) which had been fed diets containing sodium alginate at 0.5, 1.0, 2.0 g kg(-1) after five months. L. vannamei fed a diet containing 2.0 g kg(-1) sodium alginate had increased phenoloxidase activity, respiratory burst and SOD activity, but decreased GPX activity significantly. L. vannamei fed a diet containing 2.0 g kg(-1) sodium alginate had increased phagocytic activity and the shrimp fed a diet containing sodium alginate at 0.5, 1.0 or 2.0 g kg(-1) had increased clearance efficiency to V. alginolyticus. In another experiment, L. vannamei, which had been fed control diet, or sodium alginate-containing diets after 5 months, were challenged with V. alginolyticus at 2 x 10(6) colony-forming units (CFU) shrimp(-1) and then placed in seawater of 15 per thousand. The survival of shrimp fed a diet containing 2.0 g kg(-1) after one day, and the survival of shrimp fed diets containing sodium alginate at 0.5 and 1.0 g kg(-1) after 2-4 days increased significantly, as compared to that of shrimp fed control diet. It is therefore concluded that administration of sodium alginate in the diet at 2.0 g kg(-1) or less could enhance the immune ability of L. vannamei and increase its resistance to V. alginolyticus infection.

Ex vivo demonstration of nitric oxide in the rat brain: effects of intrastriatal endothelin-1 injection

Nitric oxide (NO) is a novel transmitter with multiple functions in endothelium and neuronal tissue. In particular, it has been implicated in the pathogenesis of neurodegenerative diseases. The aim of the present study was to demonstrate the ex vivo detection of NO in basal conditions and after ET-1 intrastriatal injection by means of electron paramagnetic resonance (EPR) spectroscopy using locally injected hemoglobin (Hb) as a NO trapping agent. The extent of neostriatal damage after Hb and ET-1 injections was assessed by means of immunocytochemistry with a monoclonal antibody against dopamine and cAMP-phosphoprotein M(r) 32 (DARPP-32), which is considered a marker of striatal intrinsic neurons. In the absence of local Hb injection, no signal related to endogenous NO was detected in the neostriatum, suggesting that endogenous NO trapping agents are not sufficiently concentrated to allow NO detection with the present technique. Instead, 1 h after Hb injection, a clear nitrosyl-Hb signal can be detected in neostriatal homogenates. ET-1, a powerful vasoconstrictor agent, was used to cause neuronal loss in the neostriatum. No change in nitrosyl-Hb signal was observed in neostriatal 1 h after ET-1 injection, whereas an almost 3-fold increase in the signal intensity was present 24 h after ET-1 injection. The analysis of neostriatal damage showed that Hb injection did not cause either significant damage of striatal tissue or potentiation of ET-1-induced lesions. In conclusion, the present technique allows ex vivo detection of NO in the brain. The delayed increase in NO observed after ET-1 injection indicates that this molecule may participate in the development of slowly progressive neuronal damage occurring at late post-ischemic times.

Effect of endothelin-1 induced ischemia on peroxidative damage and membrane properties in rat striatum synaptosomes

Synaptosomes obtained from rat striata lesioned by central injection of endothelin-1 (ET-1) were analyzed for the levels of lipid peroxidation products, the susceptibility to lipid peroxidation, the phospholipid and free fatty acid composition and the activity of Na+,K(+)-ATPase one hour after ET-1 treatment. The intrastriatal injection of ET-1 promoted an increase of endogenous thiobarbituric reactive substances (TBARS), as index of free radical mediated lipid damage, and a greater susceptibility to iron/ascorbate-induced lipid peroxidation. The pattern of free fatty acids showed a significant decrease of arachidonic and docosahexaenoic acid consequent to ET-1 treatment. The analysis of lipid composition showed a significant loss of phospholipids: among phospholipid species, sphingomyelin and phosphatidylethanolamine plasmalogen were particularly reduced by ET-1 treatment. The activity of membrane-bound Na+,K(+)-ATPase was also significantly reduced in synaptosomes obtained from ET-1 lesioned striata. Taken together these results indicate a significant modification of synaptosomal membrane of ET-1 treated rat striata, possibly due to a free radical mediated damage.