Analgesic and side effects of intravenous recombinant Phα1ß

Intrathecal injection of voltage-sensitive calcium channel blocker peptide toxins exerts analgesic effect in several animal models of pain. Upon intrathecal administration, recombinant Phα1ß exerts the same analgesic effects as the those of the native toxin. However, from a clinical perspective, the intrathecal administration limits the use of anesthetic drugs in patients. Therefore, this study aimed to investigate the possible antinociceptive effect of intravenous recombinant Phα1ß in rat models of neuropathic pain, as well as its side effects on motor, cardiac (heart rate and blood pressure), and biochemical parameters. Methods: Male Wistar rats and male Balb-C mice were used in this study. Giotto Biotech® synthesized the recombinant version of Phα1ß using Escherichia coli expression. In rats, neuropathic pain was induced by chronic constriction of the sciatic nerve and paclitaxel-induced acute and chronic pain. Mechanical sensitivity was evaluated using von Frey filaments. A radiotelemeter transmitter (TA11PA-C10; Data Sciences, St. Paul, MN, USA) was placed on the left carotid of mice for investigation of cardiovascular side effects. Locomotor activity data were evaluated using the open-field paradigm, and serum CKMB, TGO, TGP, LDH, lactate, creatinine, and urea levels were examined. Results: Intravenous administration of recombinant Phα1ß toxin induced analgesia for up to 4 h, with ED50 of 0.02 (0.01-0.03) mg/kg, and reached the maximal effect (Emax = 100% antinociception) at a dose of 0.2 mg/kg. No significant changes were observed in any of the evaluated motor, cardiac or biochemical parameters. Conclusion: Our data suggest that intravenous administration of recombinant Phα1ß may be feasible for drug-induced analgesia, without causing any severe side effects.(AU)

Analgesic and side effects of intravenous recombinant Ph alfa 1 beta

Background: Intrathecal injection of voltage-sensitive calcium channel blocker peptide toxins exerts analgesic effect in several animal models of pain. Upon intrathecal administration, recombinant Phα1β exerts the same analgesic effects as the those of the native toxin. However, from a clinical perspective, the intrathecal administration limits the use of anesthetic drugs in patients. Therefore, this study aimed to investigate the possible antinociceptive effect of intravenous recombinant Phα1β in rat models of neuropathic pain, as well as its side effects on motor, cardiac (heart rate and blood pressure), and biochemical parameters. Methods: Male Wistar rats and male Balb-C mice were used in this study. Giotto Biotech® synthesized the recombinant version of Phα1β using Escherichia coli expression. In rats, neuropathic pain was induced by chronic constriction of the sciatic nerve and paclitaxel-induced acute and chronic pain. Mechanical sensitivity was evaluated using von Frey filaments. A radiotelemeter transmitter (TA11PA-C10; Data Sciences, St. Paul, MN, USA) was placed on the left carotid of mice for investigation of cardiovascular side effects. Locomotor activity data were evaluated using the open-field paradigm, and serum CKMB, TGO, TGP, LDH, lactate, creatinine, and urea levels were examined. Results: Intravenous administration of recombinant Phα1β toxin induced analgesia for up to 4 h, with ED50 of 0.02 (0.01-0.03) mg/kg, and reached the maximal effect (Emax = 100% antinociception) at a dose of 0.2 mg/kg. No significant changes were observed in any of the evaluated motor, cardiac or biochemical parameters. Conclusion: Our data suggest that intravenous administration of recombinant Phα1β may be feasible for drug-induced analgesia, without causing any severe side effects.

Using an experimental model for the study of therapeutic touch / Utilização de um modelo experimental para estudo sobre o toque terapêutico / Uso de un modelo experimental para estudio sobre el toque terapéutico

OBJECTIVE: to verify whether the Paw Edema Model can be used in investigations about the effects of Therapeutic Touch on inflammation by measuring the variables pain, edema and neutrophil migration. METHOD: this is a pilot and experimental study, involving ten male mice of the same genetic strain and divided into experimental and control group, submitted to the chemical induction of local inflammation in the right back paw. The experimental group received a daily administration of Therapeutic Touch for 15 minutes during three days. RESULTS: the data showed statistically significant differences in the nociceptive threshold and in the paw circumference of the animals from the experimental group on the second day of the experiment. CONCLUSION: the experiment model involving animals can contribute to study the effects of Therapeutic Touch on inflammation, and adjustments are suggested in the treatment duration, number of sessions and experiment duration.

OBJETIVO: verificar se o modelo de edema de pata pode ser utilizado nas investigações acerca dos efeitos do toque terapêutico sobre a inflamação, mensurando-se as variáveis dor, edema e migração de neutrófilos. MÉTODO: trata-se de estudo piloto, experimental, com 10 camundongos machos da mesma linhagem genética, divididos em grupo experimental e controle, submetidos à indução química de inflamação local na pata direita traseira. O grupo experimental recebeu uma aplicação diária de toque terapêutico com duração de quinze minutos, por três dias. RESULTADOS: os dados evidenciaram diferenças estatisticamente significativas no limiar nociceptivo e na circunferência das patas dos animais do grupo experimental, no segundo dia do experimento. CONCLUSÃO: o modelo de experimento com animal pode contribuir para o estudo dos efeitos do toque terapêutico sobre a inflamação. Sugere-se ajuste no tempo de exposição, número de sessões e tempo de duração do experimento.

OBJETIVO: verificar si el Modelo de Edema de Pata puede ser utilizado en las investigaciones acerca de los efectos del Toque Terapéutico sobre la inflamación, mensurándose las variables dolor, edema y migración de neutrófilos. MÉTODO: se trata de un estudio piloto, experimental, con 10 ratones machos del mismo linaje genético, divididos en grupo experimental y control, sometidos a inducción química de inflamación local en la pata derecha trasera. O grupo experimental recibió una aplicación diaria de Toque Terapéutico con duración de quince minutos, por tres días. RESULTADOS: Los datos evidenciaron diferencias estadísticamente significativas en el umbral de nocicepción y circunferencia de las patas de los animales del grupo experimental durante el segundo día del experimento. CONCLUSIÓN: El modelo de experimento con animal puede contribuir al estudio de los efectos del Toque Terapéutico sobre la inflamación: se sugiere ajuste en el tiempo de exposición, número de sesiones y duración del experimento.