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Rat Paw (rat + paw)

Distribution by Scientific Domains
Medical Sciences100%

Terms modified by Rat Paw

  • rat paw edema
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  • rat paw oedema
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    Selected Abstracts

    The importance of brain PGE2 inhibition versus paw PGE2 inhibition as a mechanism for the separation of analgesic and antipyretic effects of lornoxicam in rats with paw inflammation

    JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 5 2009
    Dr Nobuko Futaki
    Abstract Objectives Lornoxicam is a non-selective cyclooxygenase inhibitor that exhibits strong analgesic and anti-inflammatory effects but a weak antipyretic effect in rat models. Our aim was to investigate the mechanism of separation of potencies or analgesic and antipyretic effecls of lornoxicam in relatioin to its effect on prostaglandin E2 (PGE2) production in the inflammatory paw and the brain. Methods A model of acute or chronic paw inflammation was induced by Freund's complete adjuvant injection into the rat paw. Lornoxicam (0.01,1 mg/kg), celecoxib (0.3,30 mg/kg) or loxoprofen (0.3,30 mg/kg) was administered orally to the rats and the analgesic and antipyretic effects were compared. The paw hyperalgesia was assessed using the Randall,Selitto test or the flexion test. Dorsal subcutaneous body temperature was measured as indicator of pyresis. After the measurement of activities, the rats were sacrificed and the PGE2 content in the paw exudate, cerebrospinal fluid or brain hypothalamus was measured by enzme-immunoassay. Key findings In a chronic model of arthritis, lornoxicam, celecoxib and loxoprofen reduced hyperalgesia with an effective dose that provides 50% inhibition (ED50) of 0.083, 3.9 and 4.3 mg/kg respectively, whereas the effective dose of these drugs in pyresis was 0.58, 0.31 and 0.71 mg/kg respectively. These drugs significantly reduced the PGE2 level in paw exudate and the cerebrospinal fluid. In acute oedematous rats, lornoxicam 0.16 mg/kg, celecoxib 4 mg/kg and loxoprofen 2.4 mg/kg significantly reduced hyperalgesia to a similar extent. On the other hand, lornnoxicam did not affect the elevated body temperature, whereas celecoxib and loxoprofen siginificantly reduced the pyrexia to almost the normal level. These drugs significantly reduced the PGE2 level in inflamed paw exudate lo almost the normal level. On the other hand, lornoxicam did not change PGE2 level in the brain hypothalamus, whereas celecoxib and loxoprofen strongly decreased it. Conclusions Lornoxicam exhibits strong analgesic but weak antipyretic effects in rats with paw inflammation. Such a separation of effects is related to its efficacy in the reduction of PGE2 levels in the paw and brain hypothalamus. [source]

    The inhibition of paw oedema formation caused by the oil of Copaifera multijuga Hayne and its fractions

    JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 10 2006
    Valdir F. Veiga Junior
    Two oils exuded from a Copaifera multijuga Hayne tree (Leguminosae-Caesalpinoideae), collected from the same plant, but in different periods of the year, and the hexanic, dichloromethanic and methanolic fractions of one of these oils were analysed by high-resolution gas chromatography (HRGC) and HRGC coupled with mass spectrometry (HRGC-MS). In addition, the in-vivo preliminary anti-oedematogenic actions of the oil and some fractions of it were assessed against carrageenan- and bradykinin-induced oedema formation in the rat paw. Twenty-seven sesquiterpenes and six diterpenes were identified, ,-caryophyllene, ,-copaene and copalic acid being the main components. The dichloromethanic and methanolic fractions obtained from C. multijuga oil given by the intraperitoneal route caused a significant inhibition of paw oedema caused by carrageenan with inhibition of 49 ± 13% and 64 ± 9 %, respectively. Likewise, dexamethasone (the positive control drug) also greatly inhibited carrageenan-induced paw oedema formation (60 ± 4% at 2 h). The hexanic fraction also significantly inhibited (50 ± 6%) the paw oedema formation caused by bradykinin. These results suggest the presence of still non-identified active terpene compounds in the oil of C. multijuga that exhibit anti-oedematogenic properties. Of note, the yield of these compounds and the pharmacological actions of the oil, exhibited great seasonal variations, a relevant aspect that should be carefully observed for the correct medicinal use of this plant by the population. [source]

    Antinociceptive action of the extract and the flavonoid quercitrin isolated from Bauhinia microstachya leaves

    JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 10 2005
    Vinícius M. Gadotti
    This study examined the antinociceptive effect of Bauhinia microstachya (Leguminosae), a native plant widely distributed in the South of Brazil, in several chemical and mechanical models of pain. The methanolic extract (ME) from B. microstachya (3,30 mg kg,1, i.p.) and the isolated compound quercitrin (1,10 mg kg,1, i.p.), given 30 min earlier, produced a dose-dependent inhibition of acetic-acid-induced visceral pain in mice, with a mean ID50 value (dose necessary to reduce the nociceptive response by 50% relative to the control value) of 7.9 and 2.4 mg kg,1, respectively. The ME of B. microstachya (3,100 mg kg,1, i.p., 30 min earlier) also caused a dose-dependent inhibition of capsaicin-induced pain, with a mean ID50 value of 18.8 mg kg,1. Moreover, the ME (3,100 mg kg,1, i.p., 30 min earlier) produced marked inhibition of both phases of formalin-induced pain, with mean ID50 values for the neurogenic and the inflammatory phases of 30.3 and 17.2 mg kg,1, respectively. In addition, the ME of B. microstachya (3,300 mg kg ,1, i.p., 30 min earlier) inhibited, in a graded manner, the hyperalgesia induced by bradykinin (3.2 ,g/paw), substance P (13.5 ,g/paw), carrageenan (300 ,g/paw), capsaicin (100 ,g/paw) and adrenaline (100ng/paw) in the rat paw, with mean ID50 values of 20.5, 17.9, 101.8, 54.2 and 99.7 mg kg,1, respectively. Taken together, these data demonstrate that ME of B. microstachya elicited a pronounced antinociceptive action against several chemical and mechanical models of pain in mice and rats. The precise mechanism responsible for the antinociceptive effect of the extract still remains unclear, but seems to be partly related to modulation of the release or action of pro-inflammatory mediators involved in the models of pain used. Finally, the flavonoid quercitrin isolated from this plant appears to contribute for the antinociceptive property of the methanolic extract. [source]

    Inflammatory Pain Reduction In Rats By Local Treatment With oATP, A Selective Inhibitor Of P2X7 ATP Receptor

    JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2001
    G Dell'Antonio
    Peptide neurotransmitters, as substance P or ATP, are released during inflammatiory processes by the nerve endings of sensory fibers. ATP is also released from the cytoplasm of damaged cells at the site of inflammation. It acts at the level of many P2X subtypes of purinoreceptors. The receptor for extracellular ATP named P2Z/P2X7 is selectively blocked by the periodate oxidized ATP (oATP). We have hypothesized that P2X subunits present on peripheral sensory nerve terminals, able to initiate a nociceptive signal, could be blocked by local treatment with oATP, so inducing pain relief. Male inbred Fisher rats weighing about 250 g were used. Unilateral inflammation into rat hind paw was induced by intraplantar injection of Freund's complete adjuvant (FCA). The following signs of inflammation, from 3 to 48 h after FCA injection, were detected: increased paw volume, increased paw temperature and hyperalgesia. The latter was evaluated using an algesiometric test wich measured the paw pressure threshold (PPT, expressed in g). We treated some rats, bearing paw inflammation by 12 h, with local injection of 56 ,M oATP. We showed a significant reduction of hyperalgesia in treated rats (PPT = 190 ± 2.3 in inflamed paw of oATP treated vs. PPT = 60 ± 1.6 in inflamed paw of untreated rats, at 60 min following oATP innoculation). We showed also that treatment with oATP was more efficient than treatment with diclofenac in reducing local inflammatory pain (PPT expressed as percentage of the maximum possible effect = 60 ± 0.5, at 120 min following intraplantar administration of oATP, vs. 25 ± 1.9 at the same time following intraplantar administration of diclofenac). The use of polyclonal antibody anti P2X7 receptor to perform immunohistochemical analysis of inflamed tissue, showed a reduction of receptor expression at the level of nerve endings in sections obtained from rat paw treated with oATP with respect to sections obtained from untreated rats. Such an effect was independent on the recruitment of immunocytes in inflamed tissue. Our results demonstrate that ATP exerts a key role in the pathophysiology of peripheral inflammation and that oATP may be effective in treating inflammatory pain. [source]

    Calotropis procera latex-induced inflammatory hyperalgesia , effect of bradyzide and morphine

    AUTONOMIC & AUTACOID PHARMACOLOGY, Issue 3 2007
    Vijay L. Kumar
    Summary 1,The milky white latex of the plant Calotropis procera induces inflammatory response upon accidental exposure and on local administration that could be effectively ameliorated by antihistaminic and standard anti-inflammatory drugs. 2,The aim of the present study was to evaluate the anti-oedematogenic and analgesic effect of the bradykinin antagonist, bradyzide (BDZ) and the opioidergic analgesic, morphine (Mor) against inflammatory hyperalgesia induced by the dried latex (DL) of C. procera in the rat paw oedema model. 3,An aqueous solution of DL (0.1 ml of 1% solution) was injected into the sub-plantar surface of the rat paw and the paw volume was measured at different time intervals. The inhibitory effect of bradyzide and morphine on oedema formation and hyperalgesic response was compared with that of cyproheptadine (CPH), a potent inhibitor of DL-induced oedema formation. 4,The hyperalgesic response was evaluated by the dorsal flexion pain test, compression test and by observing motility, stair-climbing ability, and the grooming behaviour of the rats. 5,The effect of these drugs was also evaluated against DL-induced writhings in the mouse model. 6,Both bradyzide and morphine inhibited DL-induced oedema formation by 30,40% and CPH was more effective in this regard (81% inhibition). The antihyperalgesic effect of both the drugs was more pronounced than that of CPH. Both bradyzide and morphine markedly inhibited the grooming behaviour and the effect of morphine could be reversed by pretreatment with naloxone. 7,Thus, our study shows that DL-induced oedema formation is effectively inhibited by antihistaminic/antiserotonergic drug and associated hyperalgesia by analgesic drugs. [source]