Hyperalgesic effect of subarachnoid administration of phentolamine in mice

Revista Brasileira de Anestesiologia

Desiré Carlos Callegari¹  João Antônio Correa¹  Oscar César Pires¹  Renan Batista Corrêa Braga¹  Ana Flávia Marques Gimbo¹  Adriana Aparecida De Souza¹  Marta Helena Rovani Pires¹  Elton Constantino¹  Irimar De Paula Posso¹ 

关键词: Mice;    Phentolamine;    Pain;    Formalin test;    von Frey;    Ratos;    Fentolamina;    Dor;    Teste da formalina;    Von Frey;    Ratones;    Fentolamina;    Dolor;    Test de la formalina;    Von Frey;   

DOI  :  10.1016/j.bjane.2013.09.013

来源: SciELO

【 摘 要 】

BACKGROUND AND OBJECTIVES: Painful phenomenon is one of the most important and complex experiences. Phentolamine is a non-selective alpha-adrenergic antagonist. The objective of this study was to compare the effect of increasing doses of phentolamine into subarachnoid space in rats in the modulation of painful phenomenon. METHODS: 84 male Wistar rats were divided into formalin and plantar incision groups, subdivided into six subgroups (n = 7). Control group received only saline (10 µL); active subgroups received phentolamine 10 µmg (GF10), 20 mg (GF20), 30 mg (GF30), 40 mg (GF40), and 50 g (GF50). In formalin group, pain was induced by injection of 50 µL of 2% formalin in dorsal region of right posterior paw. In plantar incision group, pain was induced by plantar incision and evaluated using von Frey filaments. Induction and maintenance of anesthesia were performed with 3% halothane for catheter placement into subarachnoid space and plantar incision. Statistical analysis was performed using the JMP program from SAS with 5% significance level. RESULTS: Phentolamine at doses of 20 and 30 g increased the algesic response in the intermediate phase of the formalin test. In plantar incision test, it had hyperalgic effect on first, third, fifth, and seventh days at a dose of 10 g and on first, third, and fifth days at a dose of 20 g and on fifth day at a dose of 30 g. CONCLUSION: Subarachnoid administration of phentolamine showed hyperalgesic effect, possibly due to the involvement of different subclasses of alpha-adrenergic receptors in modulating pain pathways.

【 授权许可】

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