Efeitos da glibenclamida na função e histologia renais, em ratos submetidos à hemorragia aguda sob anestesia com sevoflurano
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Data
2007-02-15
Autores
Diego, Luis Antonio dos Santos [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A glibenclamida, sulfoniluréia muito utilizada clinicamente no controle do diabetes mellitus, possui propriedade bloqueadora dos canais de potássio dependentes de adenosina trifosfatona (k+ ATP), opondo-se à possível propriedade pré-condicionante do sevoflurano. Hipovolemia conseqüente à hemorragia suscita reações compensadoras de proteção orgânica. Entretanto, mecanismos protetores como a ativação do sistema renina-angiotensina ensejam agressão renal por vasoconstrição com interferência na função depuradora. O objetivo do presente estudo foi avaliar os efeitos da glibenclamida na função e histologia renais de ratos sob anestesia com sevoflurano em cenário de choque hemorrágico. Neste intuito, estudou-se uma amostra de 20 ratos Wistar. O delineamento consistiu em estudar os animais quanto à pressão arterial, à temperatura retal e ao hematócrito e quantificar atributos da função renal, tais como: ritmo de filtração glomerular (RGF), estudar os animais quanto ao peso, pressão arterial média, temperatura retal e hematócrito e fluxo plasmático renal efetivo (FPR efetivo), fluxo sangüíneo renal e resistência vascular renal (RVR), além de se analisarem as alterações histológicas após a imposição da condição experimental. A amostra foi aleatoriamente dividida em 2 grupos de 10 animais cada (G1 e G2), entretanto apenas um destes (G2) foi submetido a tratamento com glibenclamida venosa (1 mcg.g-1), 60 min antes do início de sangria. Os animais de ambos os grupos foram anestesiados com sevoflurano a 4% sob campânula apropriada e mantidos em respiração espontânea com ar enriquecido com oxigênio, além de sofrerem sangria de 30% da volemia (esta calculada como 6% do peso corporal)...
Glibenclamide, a sulfonylurea widely used clinically for controlling diabetes mellitus, blocks adenosine triphosphate-dependent potassium (K+ ATP) channels, thus opposing the possible preconditioning property of sevoflurane. Hypovolemia from hemorrhage evokes protective compensatory reactions. However, protective mechanisms such as activation of the renin-angiotensin system result in renal impairment by vasoconstriction interfering in the clearance function. This study was designed to evaluate the effects of glibenclamide on renal function and histology in rats in a state of hemorrhagic shock under sevoflurane anesthesia. A sample of 20 Wistar rats was studied for that purpose. The design consisted in studying mean arterial pressure, rectal temperature and hematocrit and quantifying glomerular filtration rate (GFR), effective renal plasma flow (ERPF), renal blood flow (RBF) and renal vascular resistance (RVR), and analyzing histological alterations after the experimental conditions were attained. The sample was randomized into 2 groups of 10 animals each (G1 and G2), only one of which (G2) was treated with intravenous glibenclamide (1 mcg.g-1), 60 min before bleeding was begun. Both groups were anesthetized with sevoflurane at 4% under an appropriate bell jar and kept on spontaneous respiration with oxygen-enriched air, while being bled of 30% of volemia (calculated as 6% of body weight) in 3 stages with 10-min intervals. Evaluation of renal function used estimated renal clearances of paraaminohippurate (ERPF) and sodium iothalamate (GFR), while renal histology was evaluated by investigating the degree of vascular and tubular dilatation, vascular congestion, tubular vacuolization, necrosis and signs of tubular regeneration... (Complete abstract click electronic access below)
Glibenclamide, a sulfonylurea widely used clinically for controlling diabetes mellitus, blocks adenosine triphosphate-dependent potassium (K+ ATP) channels, thus opposing the possible preconditioning property of sevoflurane. Hypovolemia from hemorrhage evokes protective compensatory reactions. However, protective mechanisms such as activation of the renin-angiotensin system result in renal impairment by vasoconstriction interfering in the clearance function. This study was designed to evaluate the effects of glibenclamide on renal function and histology in rats in a state of hemorrhagic shock under sevoflurane anesthesia. A sample of 20 Wistar rats was studied for that purpose. The design consisted in studying mean arterial pressure, rectal temperature and hematocrit and quantifying glomerular filtration rate (GFR), effective renal plasma flow (ERPF), renal blood flow (RBF) and renal vascular resistance (RVR), and analyzing histological alterations after the experimental conditions were attained. The sample was randomized into 2 groups of 10 animals each (G1 and G2), only one of which (G2) was treated with intravenous glibenclamide (1 mcg.g-1), 60 min before bleeding was begun. Both groups were anesthetized with sevoflurane at 4% under an appropriate bell jar and kept on spontaneous respiration with oxygen-enriched air, while being bled of 30% of volemia (calculated as 6% of body weight) in 3 stages with 10-min intervals. Evaluation of renal function used estimated renal clearances of paraaminohippurate (ERPF) and sodium iothalamate (GFR), while renal histology was evaluated by investigating the degree of vascular and tubular dilatation, vascular congestion, tubular vacuolization, necrosis and signs of tubular regeneration... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Anestesiologia, Glibenclamida, Sevoflurano, Glibenclamide, Sevoflurane, Anesthesiology
Como citar
DIEGO, Luis Antonio dos Santos. Efeitos da glibenclamida na função e histologia renais, em ratos submetidos à hemorragia aguda sob anestesia com sevoflurano. 2007. 131 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Medicina de Botucatu, 2007.