RESUMO
Gentamicin (G) is a highly nephrotoxic aminoglucoside. It was used to experimentally induce nephrotoxicity in male Wistar rats. To find a drug capable of protecting the nephron we assayed a cardioprotector (trimetazidine, TMZ) and a hepatoprotector (N-acetyl cysteine, NAC). The rats were divided into six groups (n = 8): (A) control without drugs; (B) treated with 50 mg kg(-1) per day (i.p.) of G for 7 days; (C) diet supplemented with 20 mg kg(-1) per day of TMZ for 7 days; (D) treated with 10 mg kg(-1) per day (i.p.) of NAC for 7 days; (E) pretreated for 7 days with 20 mg kg(-1) per day of TMZ and during the following 7 days with G + TMZ; (F) pretreated for 7 days with 10 mg kg(-1) per day (i.p.) of NAC and during the following 7 days with G + NAC. Urea and creatinine as well as the excretion of urinary gamma-glutamyl transpeptidase (GGT(u)) and urinary N-acetyl-glucosaminidase (NAG(u)) were determined and structural and ultrastructural studies were carried out. Group B was used as a G-induced nephrotoxicity control. Pretreatment with TMZ (E) showed a protector effect against induced nephrotoxicity, with no biochemical or functional changes nor alterations in histoarchitecture or ultrastructure. Pretreatment with NAC (F) showed no protector effect against G-induced nephrotoxicity since no statistically significant differences were found with respect to the control group with G. We conclude that G-induced nephrotoxicity is attenuated by the cytoprotective effect of TMZ. We may infer that TMZ inhibits the reabsorption and consequently the accumulation of G in the proximal tubule cell.
Assuntos
Acetilcisteína/uso terapêutico , Sequestradores de Radicais Livres/uso terapêutico , Gentamicinas/efeitos adversos , Nefropatias/prevenção & controle , Néfrons/efeitos dos fármacos , Trimetazidina/uso terapêutico , Acetilcisteína/administração & dosagem , Acetilglucosaminidase/urina , Animais , Biomarcadores/sangue , Biomarcadores/urina , Creatinina/sangue , Sequestradores de Radicais Livres/administração & dosagem , Córtex Renal/efeitos dos fármacos , Córtex Renal/ultraestrutura , Nefropatias/induzido quimicamente , Nefropatias/patologia , Masculino , Néfrons/ultraestrutura , Ratos , Ratos Wistar , Trimetazidina/administração & dosagem , gama-Glutamiltransferase/urinaRESUMO
La Trimetazidina (TMZ) es una droga utilizada como cardioprotector, ya que previene la muerte celular secundaria a la isquemia miocárdica. Algunos investigadores le atribuyeron efecto reno-protector, actividad antioxidante y scavenger de radicales libres del oxígeno. El objetivo del presente trabajo es mostrar el efecto citoprotector de TMZ en las alteraciones inducidas por Gentamicina (G) a nivel de la célula del túbulo renal. Se diseñaron esquemas en animales de experimentación tratados con ambas drogas. Ratas macho Wistar de 180 a 200 g de peso fueron distribuidas en 5 grupos (n=8) y tratadas con: dieta estándar (A); suplementada con 20 mg/Kg/día de TMZ durante 27 días (B); suplementada con 50 mg/Kg/día de G durante 7 días(C); pretratadas 20 días con 20 mg/Kg/día de TMZ y los últimos 7 días con G (D) y tratadas simultáneamente durante 7 días con 20 mg/Kg/día de TMZ y 50 mg/Kg/día de G(E). Se midieron los compuestos nitrogenados urea y creatinina, la excreción de gamma glutamiltranspeptidasa urinaria y se efectuaron estudios estructurales con tinción de hematoxilina-eosina y ultraestructurales. Se utilizó el grupo C como testigo de nefrotoxicidad inducida por G. El pretratamiento durante 20 días con TMZ demostró el efecto protector para la nefrotoxicidad inducida, sin cambios bioquímicos-funcionales, ni alteración de la histoarquitectura, ni de la ultraestructura. El tratamiento simultáneo con TMZ y G no mostró efecto protector. Se concluye que en el modelo de ratas macho Wistar se demuestra el efecto citoprotector de TMZ en tratamiento previo por 21 días. El estudio histológico del tejido renal, bajo estas condiciones, presenta histoarquitectura conservada y función renal normal. Se infiere que el efecto citoprotector de TMZ que impide la nefrotoxicidad inducida por G se debe a la inhibición de la reabsorción y acumulación de Gentamicina en la célula del túbulo proximal del nefrón.
Trimetazidine (TMZ) is a drug used as a cardioprotector since it prevents cell death secondary to myocardial ischemia. Some investigators have attributed protective effect, antioxidant activity and oxygen free radical scavenging abilityt to TMZ. The aim of the present work is to show the cytoprotective effect of TMZ on Gentamicin (G)-induced alterations at the level of the renal tubular cell. Schemes were designed in experimental animals treated with both drugs. Male Wistar rats weighing 200 to 260 g were divided into 5 groups (n=8) and treated with: standard diet (A); standard diet supplemented with 20 mg/Kg/day of TMZ for 27 days (B); standard diet supplemented with 50 mg/Kg/day of G for 7 days (C), pretreated for 20 days with 20 mg/Kg/day of TMZ and for the last 7 days with G (D), and treated simultaneously for 7 days with 20 mg/Kg/day of TMZ and 50 mg/Kg/day of G (E). The nitrogen compounds urea and creatinine were measured and so was the excretion of urinary gamma-glutamyl transpeptidase. Structural studies with hematoxilin and eosin staining and ultrastructural studies were also performed. Gentamicin was used as a control for nephrotoxicity (group C). Pretreatment with TMZ showed a protective effect against induced nephrotoxicity, with no biochemical changes or alterations in the histoarchitecture. Simultaneous treatment with TMZ and G (group E) showed no protective effect. Conclusions: the cytoprotective effect of TMZ on G-induced nephrotoxicity would take place at the level of the proximal tubular cell of the brush border by inhibiting G reabsorption and accumulation.