Suppressions of Ischemic Paw Oedema in Mice, Rats and Guinea Pigs by Superoxide Dismutases from Different Sources

Various sources of superoxide dismutases (SOD) suppressed ischaemic paw oedemata (tourniquet poditis) of mice, rats and guinea pigs with different potencies. Intravenous (i.v.) dosing of mouse Cu, Zn-SOD had no effect on mouse ischaemic oedema, yet rat and guinea pig Cu, Zn-SOD suppressed ischaemic oedemata of rats and guinea pigs. Homologous SOD was anti-inflammatory at least in these two models. Guinea pig SOD was one of the most potent in all models, but showed a very narrow range of effective dose. This bell-shape suppressive pattern was ameliorated by concomitant catalase injection. Bovine and human Cu, Zn-SOD had a rather broad range of effective dose. Bacterial Mn-SODS were suppressive in mice, as well as the oxygen radical scavenger MK-447 and cytochrome c. Dexamethasone was effective only when administered more than 3 hrs in advance. As ischaemic paw oedema of mice was not sensitive to cyclooxy-genase and lipoxygenase inhibitors, this model could serve for screening new types of anti-inflammatory or anti-ischaemic drugs.     

Suppression of Carrageenan Paw Oedema in Rats and Mice by Heparin-Induced Ec-Sods

Carrageenan-induced paw edemata of mice and rats were suppressed by 1–4 × 10³U/kg intravenous injection of heparin. High doses were less suppressive, corresponding well to the increase in plasma SOD activity. This biphasic dose response curve was also observed in our ischemic paw model of mice. Increased SOD appeared as high molecular EC-SOD C (in mice) and B (in rats) as a result of its sensitivity to a copper chelator and long retention time in the blood stream, compared to the short life of cytosolic Cu, Zn-SOD. EC-SOD C (135 kDa) failed to be detected in the plasma of heparin-injected mice by way of nitroblue tetrazolium staining after PAGE electrophoresis. Instead, SOD activity was found near 270 kDa. An excess heparin-loaded subunit of this enzyme might become inactivated or might not be able to fix to a pocket where EC-SOD eliminates O₂^?. to protect the endothelium, Electrophoresis dissociates the excess heparin resulting in an active form of [he enzyme. Paw edemata of rats were less sensitive because this species lacks the strongly heparin-binding EC-SOD C and has only the weakly heparin-binding EC-SOD B. Ischemia-induced mitochondrial swelling of the paw muscle was observed by electron microscopy and was prevented by heparin injection.     

Change of Cu,Zn-superoxide Dismutase Activity of Guinea Pig Lung in Experimental Asthma

Correlation between the level of reactive oxygen species (ROS) generated by airway inflammatory cells and superoxide dismutase (SOD) activity of pulmonary tissue during an asthma attach was investigated in a guinea pig model of allergic asthma. In addition, the influence of SOD inhibition by diethyldithiocarbamate (DDC, Cu-chelating agent) on the airway was investigated in terms of pulmonary function during an asthma attach. Relative to controls, the capacity of bronchoalveolar lavage fluid (BAL) cells to release ROS was significantly increased in guinea pigs sensitized with ovalbumin (OA) as the antigen, and significantly increased in guinea pigs with an asthma attack provoked by the inhalation of OA. SOD activity was increased significantly in the antigen-sensitized group. The asthma provocation group showed a tendency for increase in total SOD activity, compared with the sensitization group, whose increase was dependent on the increase in copper, zinc-SOD (Cu, Zn-SOD) activity. Pretreatment with DDC increased the severity and duration of the asthma attack. These results were indicated that Cu, Zn-SOD was closely involved in the asthma process, particularly in the scavenging of oxygen radicals secreted from BAL cells.     

Change of Cu,Zn-superoxide dismutase activity of guinea pig lung in experimental asthma

Correlation between the level of reactive oxygen species (ROS) generated by airway inflammatory cells and superoxide dismutase (SOD) activity of pulmonary tissue during an asthma attach was investigated in a guinea pig model of allergic asthma. In addition, the influence of SOD inhibition by diethyldithiocarbamate (DDC, Cu-chelating agent) on the airway was investigated in terms of pulmonary function during an asthma attach. Relative to controls, the capacity of bronchoalveolar lavage fluid (BAL) cells to release ROS was significantly increased in guinea pigs sensitized with ovalbumin (OA) as the antigen, and significantly increased in guinea pigs with an asthma attack provoked by the inhalation of OA. SOD activity was increased significantly in the antigen-sensitized group. The asthma provocation group showed a tendency for increase in total SOD activity, compared with the sensitization group, whose increase was dependent on the increase in copper, zinc-SOD (Cu, Zn-SOD) activity. Pretreatment with DDC increased the severity and duration of the asthma attack. These results were indicated that Cu, Zn-SOD was closely involved in the asthma process, particularly in the scavenging of oxygen radicals secreted from BAL cells.     

Cromoglycate and nedocromil enhanced the reactive oxygen species-dependent suppressions with, but not without, dexamethasone in ischaemic and histamine paw oedema of mice

Anti-inflammatory actions of two anti-allergic drugs, alone or with dexamethasone (Dex) were examined in two models, because inflammation is claimed to be important for allergic events, especially for asthma. Cromoglycate and nedocromil were tested in ischaemic- and histamineinduced paw oedema models of mice. These antiallergic drugs (1-100 mg/kg, i.p.) failed to suppress these oedemata, but enhanced the suppressions by a low dose of dexamethasone (0.1 mg/kg, s.c.) at 3-8 h after Dex injection. The mode of effects by anti-allergic drugs resembled that of a natural antioxidant (alpha-tocopherol, beta-carotene etc.), and was different from that of an immunosuppressant like FK506. The enhancing potencies of the two anti-allergic drugs were similar at 6 h after Dex in both oedemata, and were diminished by superoxide dismutase (SOD) or catalase (i.p.). Cycloheximide completely abolished suppressions. Nedocromil, but not cromoglycate, inhibits inflammatory events. Therefore, there are common unknown actions by which the two anti-allergics enhance suppression by Dex. A possible mechanism of this action was supposed to enhance the superoxide and/or hydrogen peroxide-dependent glucocorticoid receptor (GR) signalling in the target cells.     

Effect of superoxide dismutase on the development of preimplantation mouse embryos

The role of superoxide dismutase (SOD) was tested on preimplantation development of mouse embryos in vitro. The presence of SOD in ovarian antral follicles and in oviductal and uterine secretions was also investigated. Zygotes from superovulated ICR female mice were cultured in modified Whittingham's T6 medium supplemented with SOD (0 to 370 U) or EDTA (100 muM) at 37 degrees C under 5% CO(2) in air. Supplementation of SOD (370 U) significantly promoted the development of zygotes to the blastocyst stage (45%) as compared to that of the controls (1.4%). This favorable effect of SOD was comparable to that of EDTA and completely suppressed by anti-SOD antibody. Blastocysts cultured with SOD consisted of 78.2+/-10.4 blastomeres and possessed as many blastomeres as those (81.6+/-9.3) developing in vivo; blastocysts cultured with EDTA had significantly fewer blastomeres (42.6+/-13.7). These findings suggest that SOD protects embryos against oxidative insults and that it can be an effective substitute for EDTA for supporting mouse embryo development in vitro. The SOD activity was detected in 3 different lumina from mouse reproductive organs, and SOD was identified as a cytosolic Cu,Zn-SOD on photochemically stained polyacrylamide gels. Our results suggest that oxidative injury may be responsible for developmental retardation of preimplantation-stage mouse embryos in vitro and that Cu,Zn-SOD may play a crucial role in protecting embryos against oxygen toxicity in vivo as well as in vitro.     

Effect of ricinoleic acid in acute and subchronic experimental models of inflammation

Observational studies indicate that topical application of ricinoleic acid (RA), the main component of castor oil, exerts remarkable analgesic and anti-inflammatory effects. Pharmacological characterization has shown similarities between the effects of RA and those of capsaicin, suggesting a potential interaction of this drug on sensory neuropeptide-mediated neurogenic inflammation. The aim of this study was to assess RA anti-inflammatory activities in comparison with capsaicin in several models of acute and subchronic inflammation. The acute inflammation was induced by intradermal injection of carrageenan in the mouse or by histamine in the guinea-pig eyelid. In either experiment, the extent of the oedema thickness was measured. Subchronic oedema was induced by complete Freund's adjuvant injection in the ventral right paw of mice. Tissue substance P (SP) was measured in the carrageenan experiments by radioimmunoassay (RIA). It was found that the acute topical application of RA (0.9 mg/mouse) or capsaicin (0.09 mg/mouse) significantly increased the mouse paw oedema induced by carrageenan, while an 8-day repeated topical treatment with the same doses of both compounds resulted in a marked inhibition of carrageenan-induced paw oedema matched by a reduction in SP tissue levels. Similar effects were found against histamine-induced eyelid oedema in guinea-pigs after acute or repeated application of RA or capsaicin. RA and capsaicin given for 1-3 weeks reduced the established oedema induced by Freund's adjuvant, a subchronic model of inflammation, particularly if given by the intradermal route. Either in mouse paw or in guinea-pig eyelid, capsaicin but not RA by itself produced a slight hyperemia and activation of a behavioural response (e.g. scratching of the eyelids). On the basis of the present results, RA may be seen as a new capsaicin-like, non-pungent anti-inflammatory agent suitable for peripheral application.     

Pharmacological profile of AA-861, A 5-lipoxygenase inhibitor

AA-861, a selective 5-lipoxygenase inhibitor, suppressed A23187-induced formations of 5-HETE and LTB₄ in rat peritoneal macrophages. Immunologically-stimulated generation of SRS-A was also inhibited in guinea pig lung and rat peritoneal cavity. AA-861 had no effects on histamine release from rat mast cels or passive cutaneous anaphylaxis in rats. Essentially no antagonistic activity to LDT₄ or histamine was observed. This compound exerted an obvious inhibition of allergic bronchoconstriction in guinea pigs and a moderate reduction of carrageenin-induced paw edema and pleurisy in rats. These findins suggest that SRS-A plays an important role in asthmatic and inflammatory reactions.     

Role of Cu,Zn-SOD in the synthesis of endogenous vasodilator hydrogen peroxide during reactive hyperemia in mouse mesenteric microcirculation in vivo

We have recently demonstrated that endothelium-derived hydrogen peroxide (H2O2) is an endothelium-derived hyperpolarizing factor and that endothelial Cu/Zn-superoxide dismutase (SOD) plays an important role in the synthesis of endogenous H2O2 in both animals and humans. We examined whether SOD plays a role in the synthesis of endogenous H2O2 during in vivo reactive hyperemia (RH), an important regulatory mechanism. Mesenteric arterioles from wild-type and Cu,Zn-SOD(-/-) mice were continuously observed by a pencil-type charge-coupled device (CCD) intravital microscope during RH (reperfusion after 20 and 60 s of mesenteric artery occlusion) in the cyclooxygenase blockade under the following four conditions: control, catalase alone, N(G)-monomethyl-L-arginine (L-NMMA) alone, and L-NMMA + catalase. Vasodilatation during RH was significantly decreased by catalase or L-NMMA alone and was almost completely inhibited by L-NMMA + catalase in wild-type mice, whereas it was inhibited by L-NMMA and L-NMMA + catalase in the Cu,Zn-SOD(-/-) mice. RH-induced increase in blood flow after L-NMMA was significantly increased in the wild-type mice, whereas it was significantly reduced in the Cu,Zn-SOD(-/-) mice. In mesenteric arterioles of the Cu,Zn-SOD(-/-) mice, Tempol, an SOD mimetic, significantly increased the ACh-induced vasodilatation, and the enhancing effect of Tempol was decreased by catalase. Vascular H(2)O(2) production by fluorescent microscopy in mesenteric arterioles after RH was significantly increased in response to ACh in wild-type mice but markedly impaired in Cu,Zn-SOD(-/-) mice. Endothelial Cu,Zn-SOD plays an important role in the synthesis of endogenous H(2)O(2) that contributes to RH in mouse mesenteric smaller arterioles.     

Guinea pig chymase is leucine-specific: a novel example of functional plasticity in the chymase/granzyme family of serine peptidases

To explore guinea pigs as models of chymase biology, we cloned and expressed the guinea pig ortholog of human chymase. In contrast to rats and mice, guinea pigs appear to express just one chymase, which belongs to the alpha clade, like primate chymases and mouse mast cell protease-5. The guinea pig enzyme autolyzes at Leu residues in the loop where human chymase autolyzes at Phe. In addition, guinea pig alpha-chymase selects P1 Leu in a combinatorial peptide library and cleaves Ala-Ala-Pro-Leu-4-nitroanilide but has negligible activity toward substrates with P1 Phe and does not cleave angiotensin I. This contrasts with human chymase, which cleaves after Phe or Tyr, prefers P1 Phe in peptidyl 4-nitroanilides, and avidly hydrolyzes angiotensin I at Phe8 to generate bioactive angiotensin II. The guinea pig enzyme also is inactivated more effectively by alpha1-antichymotrypsin, which features P1 Leu in the reactive loop. Unlike mouse, rat, and hamster alpha-chymases, guinea pig chymase lacks elastase-like preference for P1 Val or Ala. Partially humanized A216G guinea pig chymase acquires human-like P1 Phe- and angiotensin-cleaving capacity. Molecular models suggest that the wild type active site is crowded by the Ala216 side chain, which potentially blocks access by bulky P1 aromatic residues. On the other hand, the guinea pig pocket is deeper than in Val-selective chymases, explaining the preference for the longer aliphatic side chain of Leu. These findings are evidence that chymase-like peptidase specificity is sensitive to small changes in structure and provide the first example of a vertebrate Leu-selective peptidase.     

Studies on hormonal regulation of lipolysis and lipogenesis in fat cells of various mammalian species

1. Corticotropin-stimulated lipolysis in adipocytes of rats, mice, hamsters, guinea pigs and rabbits. Melanotropins elicited high lipolytic activity only in guinea pig and rabbit adipocytes. Opiate peptides were active only in rabbit adipocytes. Pituitary and chorionic gonadotropins and somatotropin were lipolytic in guinea pig adipocytes. Other hormones tested including prolactin, somatostatin, substance P, neurotensin, angiotensin II, thyrotropin releasing hormone and pancreatic polypeptide were devoid of lipolytic activity in all of the adipocytes studied. 2. In the rabbit adipocytes gamma-melanotropin was lipolytic only at high doses. At these doses the peptide inhibited the lipolytic response to a high dose of corticotropin. 3. Lipolysis stimulated by vasoactive intestinal peptide and epinephrine in rat adipocytes was antagonized by insulin. The lipolytic hormones corticotropin, epinephrine, vasoactive intestinal peptide and secretin suppressed basal and insulin-stimulated lipogenesis.     

Changes in superoxide production rate and in superoxide dismutase and glutathione peroxidase activities in subcellular organelles in mouse liver under exposure to low doses of low-intensity radiation

The functioning of the antioxidant system in mouse liver at increased stationary concentration of active oxygen species induced by whole-body chronic exposure of mice to gamma-irradiation (137Cs, 0.6 cGy/day, 9 days) was studied. Synchronous changes (growth with an extreme) in activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) are found that may be considered as evidence in favor of maintenance of regulatory links in the antioxidant system of liver. The superoxide production rate in microsomes and nuclei also changed with an extreme with the rise in accumulated radiation dose. In microsomes the superoxide production rate reached a maximum at lower doses than the activity of Cu,Zn-SOD did. In nuclei the increase in superoxide production rate was not compensated by the rise in Cu,Zn-SOD activity within the studied dose range. The findings indicate some imbalance between production and consumption of superoxide radicals in microsomes and nuclei; in mitochondria these processes are balanced, leading to more resistance to low-dose irradiation.     

Heparin, A Potent Releasing Agent of Extracellular Superoxide Dismutase (EC-SOD C), Suppresses Ischaemic Paw Oedema in Mice

Heparin (2,000 U/kg, i.v.) increases the plasma superoxide dismutase (SOD) activity by 2-3 times after 5min. followed by a gradual decrease. A high dose of heparin (4 × 10³ and 10 × 10³U/kg) exhibits a lower increase in the release of SOD. Ischaemic paw oedema in mice was suppressed by various types of SOD and heparin also suppresses this oedema. The dose-dependent curve of heparin of oedema suppression corresponds well with the increased plasma level of SOD. Inducibility with heparin, slow clearance from the bloodstream and blocking of oedema suppression by the copper chelator, diethyldithiocarbamate (DDC), suggest that the oedema suppressing SOD was the extracellular (EC)-SOD C. Other anticoagulants such as citrate and EDTA had no effect. Chondroitin sulphate A and C or carrageenan exhibited weak suppression. A complex of EC-SOD C and heparin appears not to bind to the endothelium in contrast to the injected free EC-SOD C. When heparin is re-injected, more than 1 week was required to get the same degree of oedema suppression. This indicates the necessity of newly synthesized enzyme. A biological role for heparin-induced release of plasma SOD is demonstrated for the first time in this investigation.     

Anti-inflammatory activity of amylin and CGRP in different experimental models of inflammation

The anti-inflammatory activity of amylin was studied in different models of inflammation, and compared to that of CGRP. Both peptides were active against mouse ear oedema induced by croton oil and acetic acid-induced peritonitis in the rat. CGRP was more potent than amylin in both models. Pretreatment with CGRP 8–37 fragment blocked the anti-inflammatory activity of both peptides in croton oil ear oedema. No anti-inflammatory activity was evidenced against serotonin-induced rat paw oedema and plasma protein extravasation induced by dextran in rat skin. Our results suggest that amylin exerts anti-inflammatory activity only in inflammatory models characterized by a vascular component. This effect appears to be mediated by the involvement of CGRP receptors.     

Niridazole suppression of experimental allergic encephalomyelitis in Lewis rats.

Administration of niridazole to Lewis rats beginning 2 days before sensitization with guinea pig spinal cord in combination with immunologic adjuvants exerted a dose related suppressive influence on development of experimental allergic encephalomyelitis (EAE). A daily dose of 75 mg/kg completely prevented clinical neurologic signs as well as markedly suppressed occurrence of immunohistopathologic manifestations of this autoimmune disease. A higher daily dose level of niridazole, i.e., 100 mg/k, also inhibited EAE but was associated with neurotoxic manifestations.     

Effects of the opiate antagonists diprenorphine and naloxone and of selected opiate agonists on feeding behavior in guinea pigs

Opiate-sensitive feeding behavior has now been demonstrated in a number of species. We sought information on which opioid receptors might be involved in the observed feeding behaviors. Guinea pigs are known to have higher concentrations of the opioid kappa receptor than any other laboratory animal, so we compared the feeding suppressive potency of the general opiate antagonist, diprenorphine to that of the relatively more mu-specific antagonist, naloxone in that species. We found that diprenorphine was over twenty times more effective than naloxone in suppressing feeding in guinea pigs, suggesting the importance of receptors other than mu in feeding initiation in the guinea pig. Confirmatory evidence for the role of kappa receptors was sought, but not found, in comparisons of the effectiveness of different types of opiate agonists in promoting feeding in these animals. These agonists suppressed, rather than stimulated feeding. We conclude that no feeding stimulatory effects of opiates can be demonstrated in guinea pigs. This observation may indicate that opioids play little role in the natural regulation of feeding in this species or that opioids result in prolonged sedation during which the animals fail to eat. The greater feeding suppressive potency of diprenorphine, a general opiate antagonist, versus naloxone, a mu-preferential antagonist, indicates that to whatever extent opiates are involved in guinea pig feeding, the opiate effect is probably not a mu receptor effect.     

Heparin,A Potent Releasing Agent of Extracellular Superoxide Dismutase (EC-SOD C), Suppresses Ischaemic Paw Oedema in Mice

Heparin (2,000 U/kg, i.v.) increases the plasma superoxide dismutase (SOD) activity by 2-3 times after 5min. followed by a gradual decrease. A high dose of heparin (4 × 10³ and 10 × 10³U/kg) exhibits a lower increase in the release of SOD. Ischaemic paw oedema in mice was suppressed by various types of SOD and heparin also suppresses this oedema. The dose-dependent curve of heparin of oedema suppression corresponds well with the increased plasma level of SOD. Inducibility with heparin, slow clearance from the bloodstream and blocking of oedema suppression by the copper chelator, diethyldithiocarbamate (DDC), suggest that the oedema suppressing SOD was the extracellular (EC)-SOD C. Other anticoagulants such as citrate and EDTA had no effect. Chondroitin sulphate A and C or carrageenan exhibited weak suppression. A complex of EC-SOD C and heparin appears not to bind to the endothelium in contrast to the injected free EC-SOD C. When heparin is re-injected, more than 1 week was required to get the same degree of oedema suppression. This indicates the necessity of newly synthesized enzyme. A biological role for heparin-induced release of plasma SOD is demonstrated for the first time in this investigation.     

Anti-inflammatory activity of superoxide dismutase conjugated with sodium hyaluronate

Superoxide dismutase (SOD) from bovine erythrocytes was conjugated with sodium hyaluronate (HA) with a mean molecular weight of 106 to have greater anti-inflammatory activity in vivo. Amino groups of SOD were coupled with carboxyl groups in the hyaluronate molecule using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. The HA-SOD conjugate was composed of 1.5 mol of SOD molecule per 1 mol of hyaluronate on the average, and retained 70% of the activity of unmodified SOD. The conjugate was essentially non-immunogenic in mice, and exhibited much higher anti-inflammatory activities than HA or SOD in models of inflammatory diseases such as ischemic oedema of the foot-pad in mice, carrageenin-induced pleurisy and adjuvant arthritis in rats. This revised version was published online in November 2006 with corrections to the Cover Date.     

Isolation of a haemorrhagic protein toxin (SA-HT) from the Indian venomous butterfish (Scatophagus argus, Linn) sting extract

A haemorrhagic protein toxin (SA-HT) was isolated and purified from the spine extract of the Indian venomous butterfish, S. argus Linn, by two step ion exchange chromatography. The toxin was homogeneous in native and SDS-PAGE gel. SDS-molecular weight of the toxin was found to be 18.1 +/- 0.09 kDa. SA-HT produced severe haemorrhage on stomach wall but devoid of cutaneous haemorrhage. UV, EDTA, trypsin, protease, cyproheptadine, indomethacin, acetylsalicylic acid and BW755C treatment significantly antagonized the haemorrhagic activity of SA-HT. The toxin produced dose and time dependent oedema on mice hind paw, which was significantly encountered by cyproheptadine, indomethacin and BW755C. SA-HT increased capillary permeability on guinea pig dorsal flank. On isolated guineapig ileum, rat fundus and uterus, SA-HT produced slow contraction which was completely antagonised by prostaglandin blocker SC19220. On isolated rat duodenum, SA-HT produced slow relaxation. SA-HT significantly increased plasma plasmin, serum MDA level and decreased serum SOD level indicating the possible involvement of cyclooxygenase and lipooxygenase pathway.     

Anti-inflammatory and analgesic activity of ononitol monohydrate isolated from Cassia tora L. in animal models

Ononitol monohydrate (OM) was isolated from Cassia tora L. leaves. The anti-inflammatory and analgesic activities of OM have been examined in male Wistar rats and mice. The efficacy of OM against inflammation was studied by using carrageenan-induced paw oedema, croton oil-induced ear oedema, acetic acid-induced vascular permeability, cotton pellet-induced granuloma and adjuvant-induced arthritis. The analgesic activity of OM was assessed using the acetic acid-induced abdominal constriction response, formalin-induced paw licking response and the hot-plate test. In acute type inflammation models, maximum inhibitions of 50.69 and 61.06% (P < .05) were noted with 20 mg/kg of OM in carrageenan-induced hind paw oedema and croton oil-induced ear oedema, respectively. Treatment of OM (20 mg/kg) meaningfully (P < .05) reduced the granuloma tissue formation by cotton pellet study at a rate of 36.25%. OM (20 mg/kg) inhibited 53.64% of paw thickness in adjuvant-induced arthritis model. OM has also been produced significant (P < .05) analgesic activity in acetic acid-induced abdominal constriction response, formalin-induced paw licking response and in hot-plate test suggesting its peripheral and central analgesic potential. The outcomes of the present study proposed that OM influenced on the anti-inflammatory and analgesic activities.