The superoxide anion donor, potassium superoxide, induces pain and inflammation in mice through production of reactive oxygen species and cyclooxygenase-2

It is currently accepted that superoxide anion (O2•−) is an important mediator in pain and inflammation. The role of superoxide anion in pain and inflammation has been mainly determined indirectly by modulating its production and inactivation. Direct evidence using potassium superoxide (KO2), a superoxide anion donor, demonstrated that it induced thermal hyperalgesia, as assessed by the Hargreaves method. However, it remains to be determined whether KO2 is capable of inducing other inflammatory and nociceptive responses attributed to superoxide anion. Therefore, in the present study, we investigated the nociceptive and inflammatory effects of KO2. The KO2-induced inflammatory responses evaluated in mice were: mechanical hyperalgesia (electronic version of von Frey filaments), thermal hyperalgesia (hot plate), edema (caliper rule), myeloperoxidase activity (colorimetric assay), overt pain-like behaviors (flinches, time spent licking and writhing score), leukocyte recruitment, oxidative stress, and cyclooxygenase-2 mRNA expression (quantitative PCR). Administration of KO2 induced mechanical hyperalgesia, thermal hyperalgesia, paw edema, leukocyte recruitment, the writhing response, paw flinching, and paw licking in a dose-dependent manner. KO2 also induced time-dependent cyclooxygenase-2 mRNA expression in the paw skin. The nociceptive, inflammatory, and oxidative stress components of KO2-induced responses were responsive to morphine (analgesic opioid), quercetin (antioxidant flavonoid), and/or celecoxib (anti-inflammatory cyclooxygenase-2 inhibitor) treatment. In conclusion, the well-established superoxide anion donor KO2 is a valuable tool for studying the mechanisms and pharmacological susceptibilities of superoxide anion-triggered nociceptive and inflammatory responses ranging from mechanical and thermal hyperalgesia to overt pain-like behaviors, edema, and leukocyte recruitment.

The superoxide anion donor, potassium superoxide, induces pain and inflammation in mice through production of reactive oxygen species and cyclooxygenase-2.

It is currently accepted that superoxide anion (O2•-) is an important mediator in pain and inflammation. The role of superoxide anion in pain and inflammation has been mainly determined indirectly by modulating its production and inactivation. Direct evidence using potassium superoxide (KO2), a superoxide anion donor, demonstrated that it induced thermal hyperalgesia, as assessed by the Hargreaves method. However, it remains to be determined whether KO2 is capable of inducing other inflammatory and nociceptive responses attributed to superoxide anion. Therefore, in the present study, we investigated the nociceptive and inflammatory effects of KO2. The KO2-induced inflammatory responses evaluated in mice were: mechanical hyperalgesia (electronic version of von Frey filaments), thermal hyperalgesia (hot plate), edema (caliper rule), myeloperoxidase activity (colorimetric assay), overt pain-like behaviors (flinches, time spent licking and writhing score), leukocyte recruitment, oxidative stress, and cyclooxygenase-2 mRNA expression (quantitative PCR). Administration of KO2 induced mechanical hyperalgesia, thermal hyperalgesia, paw edema, leukocyte recruitment, the writhing response, paw flinching, and paw licking in a dose-dependent manner. KO2 also induced time-dependent cyclooxygenase-2 mRNA expression in the paw skin. The nociceptive, inflammatory, and oxidative stress components of KO2-induced responses were responsive to morphine (analgesic opioid), quercetin (antioxidant flavonoid), and/or celecoxib (anti-inflammatory cyclooxygenase-2 inhibitor) treatment. In conclusion, the well-established superoxide anion donor KO2 is a valuable tool for studying the mechanisms and pharmacological susceptibilities of superoxide anion-triggered nociceptive and inflammatory responses ranging from mechanical and thermal hyperalgesia to overt pain-like behaviors, edema, and leukocyte recruitment.

Efeito da radiação vermelha de baixa intensidade sobre o sêmen canino criopreservado / Effect of low intensity red light on the canine semen cryopreservation

O objetivo geral deste trabalho foi analisar o efeito da radiação vermelha de baixa intensidade sobre alguns parâmetros cinéticos do espermatozoide canino criopreservado. Ejaculados de oito cães adultos foram centrifugados, rediluídos em meio tris-gema de ovo com 6% de glicerol, e, posteriormente, fracionados em: T1: incidência de radiação vermelha (660 NM) (Fisioled - Mmoptics - 100mW) por 60 segundos, antes do resfriamento e após a descongelação; T2: incidência somente antes do resfriamento; T3: incidência somente após a descongelação; e T4: sem incidência. Após a descongelação, as amostras foram submetidas ao TTR utilizando-se Sperm Class Analyzer(r). No TTR0, TTR60 e TTR90, não houve diferença entre as variáveis analisadas pelo CASA. Somente no TTR30 os efeitos da incidência da radiação vermelha foram evidentes e significativos em T1 e T2; T1 resultou em baixa MT (12,5 + 10,6%) e T2 determinou o melhor resultado de MT 40,3 + 26,1%. De forma similar T1 apresentou maior número de espermatozoides estáticos (77,5±28,9%) em relação ao T2 (50,6±28%). Concluiu-se que a dupla incidência de radiação vermelha de baixa intensidade antes do resfriamento e após a descongelação teve efeito deletério sobre a motilidade do espermatozoide canino, expressa principalmente aos 30 minutos após descongelação.

The aim of this study was to analyze the effect of low intensity red light on some kinetic parameters of cryopreserved canine sperm. Ejaculates from 08 adult dogs were centrifuged, diluted in Tris-egg yolk with 6% glycerol, and subsequently separated into: T1: incidence of red light (660 nm) (Fisioled -MMOptics - 100mW) for 60 seconds before the cooling and after thawing, T2: just before cooling, T3: only after thawing, and T4: no incidence. After thawing the samples were subjected to TTR using Sperm analyzer(r). In TTR0, TTR60 and TTR90 there were no differences between the variables analyzed by CASA. Only in TTR30 the effects of the incidence of red light were visible and significant in T1 and T2. T1 resulted in low MT (12.5 ±10.6%) and T2 determined the best result of MT 26.1%±40.3. Similarly T1 showed a higher number of static spermatozoa (77.5±28.9%) compared to T2 (50.6±28%). We concluded that the double incidence of low intensity red light, before cooling and after thawing, had a deleterious effect on canine sperm motility expressed at 30 minutes after thawing.