Terazosin and propranolol as blockers to the deleterious effect of nicotine in a random skin flap, in the rat

Abstract

Terazosin and propranolol as blockers to the deleterious effect of nicotine in a random skin flap, in the rat 1Terazosina e propanolol como bloqueadores do efeito deletério da nicotina em um retalho cutâneo randômico, no rato ______________________________________________________________________ ABSTRACT PURPOSE: To evaluate the effect of Terazosin and Propranolol on the prevention of necrosis induced by nicotine, in a random skin flap. METHODS: This study utilized 32 adult male Wistar-EPM rats divided, at random, into four groups of eight animals each. All the 32 animals received nicotine (2 mg/kg/day) subcutaneously, for one week before and one week after flap elevation. CG (Control) group received distilled water (0.2 ml/day) by gavage and saline (0.5 ml) intraperitoneally, for seven days in the postoperative period. TG (Terazosin) group received terazosin hydrochloride (3 mg/day) by gavage and saline, intraperitoneally, for seven days in the postoperative period. PG (Propranolol) group received propranolol (1.5 mg/day) intraperitoneally and distilled water, by gavage, following the stablished pattern. TPG (Terazosin + Propranolol) group received both drugs. On the seventh postoperative day, the distal necrotic area of the flaps was determined via the paper template method. Blood and skin samples were collected in order to allow determination of Malondialdehyde (MDA) levels RESULTS: The control group had a mean value of 39.5 % of necrosis; the Terazosin group 25.1 %; the Propranolol group 34.5 % and the Terazosin + Propranolol group 26.2 % of necrosis. MDA levels in the serum and in the skin samples behave similarly, with an exception regarding Propranolol group in this case. CONCLUSION: Terazosin is effective in the prevention of necrosis in this animal model and Propranolol is not effective in this case. RESUMO OBJETIVO: O objetivo deste estudo experimental foi avaliar o efeito da Terazosina e do Propranolol na prevenção da necrose induzida pela nicotina, em um retalho cutâneo randômico. 187 187 MÉTODOS: Este estudo utilizou 32 ratos machos adultos Wistar-EPM divididos, ao acaso, em quatro grupos de oito animais. Todos os 32 animais receberam nicotina (2 mg/kg/dia), por via subcutânea, por uma semana antes e uma semana após a elevação do retalho. O grupo CG (Controle) recebeu água destilada (0,2 ml/dia), por gavagem e salina (0,5 ml), por via intraperitoneal, por sete dias no período pós-operatório. O grupo TG (Terazosina) recebeu terazosina (3 mg/dia), por gavagem, e salina, intraperitoneal, por sete dias no pósoperatório. O grupo PG (Propranolol) recebeu propranolol (1,5 mg/dia), intraperitoneal e água destilada, por gavagem, seguindo o padrão estabelecido. O grupo TPG (Terazosina + Propranolol) recebeu ambas as drogas. No sétimo dia de pós-operatório, a área de necrose distal dos retalhos foi determinada pelo método do gabarito de papel. Amostras de sangue e de pele foram coletadas de forma a permitir a determinação dos níveis de malondialdeído (MDA). RESULTADOS: O grupo controle apresentou um valor médio...

Analysis of effect isoxsuprine hydrochloride and nicotine in the Transverse Rectus Abdominis Myocutaneous flap (TRAM) in rats

“…In an attempt to neutralize the harmful effects of nicotine and reduce the areas of flap necrosis several medications were used 19,20 . Desvascularization cranial of the Transverse Rectus Abdominis Myocutaneous flap (TRAM) in rats was a surgical technique used to induce a programmed and intentional tissue ischemia in flaps, making them survive with less blood flow than usual, causing a stimulus of increased internal vascularity, leading to reduced areas of necrosis flap were also used [21][22][23] .…”

“…The isoxsuprine hydrochloride produces peripheral vasodilation by a direct effect on vascular smooth muscle, primarily within skeletal muscle, with little effect on cutaneous blood flow [9][10][11][12][13] . In an attempt to neutralize the harmful effects of nicotine and reduce the areas of flap necrosis isoxsuprine hydrochloride was used 19,20 . …”

Ação da l-arginina na evolução de retalhos cutâneos de ratos sob exposição à nicotina

“…It was found that the association between the drugs improved clinical response with survival of the flaps, and the authors considered the association as effective in reversing the effects caused by nicotine 21 . The dose of 2mg/kg of nicotine and the subcutaneous administration used in this study were also used to evaluate the effects of terazosin, a neuroreceptor antagonist, and demonstrated their effectiveness in preventing necrosis, but when combined with propranolol, a beta-blocker, the previous protective effect of necrotic reaction was not observed 22 .…”

Modelos experimentais em pesquisa

“…Também é possível testar o efeito benéfico de fármacos como a terazocina sobre a circulação desses retalhos. 15 Esse modelo experimental também tem sido utilizado para a avaliação do efeito da Estimulação Elétrica Nervosa Transcutânea (TENS) sobre a viabilidade desse retalho cutâneo randômico. 16 Também existem pesquisas da utilização desse modelo experimental no estudo de alterações bioquímicas seqüenciais do estresse oxidativo sobre o retalho.…”