ABSTRACT
Obstructive apnea (OA) can exert significant effects on renal sympathetic nerve activity (RSNA) and hemodynamic parameters. The present study focuses on the modulatory actions of RSNA on OA-induced sodium and water retention. The experiments were performed in renal-denervated rats (D; N = 9), which were compared to sham (S; N = 9) rats. Mean arterial pressure (MAP) and heart rate (HR) were assessed via an intrafemoral catheter. A catheter was inserted into the bladder for urinary measurements. OA episodes were induced via occlusion of the catheter inserted into the trachea. After an equilibration period, OA was induced for 20 s every 2 min and the changes in urine, MAP, HR and RSNA were recorded. Renal denervation did not alter resting MAP (S: 113 ± 4 vs D: 115 ± 4 mmHg) or HR (S: 340 ± 12 vs D: 368 ± 11 bpm). An OA episode resulted in decreased HR and MAP in both groups, but D rats showed exacerbated hypotension and attenuated bradycardia (S: -12 ± 1 mmHg and -16 ± 2 bpm vs D: -16 ± 1 mmHg and 9 ± 2 bpm; P < 0.01). The basal urinary parameters did not change during or after OA in S rats. However, D rats showed significant increases both during and after OA. Renal sympathetic nerve activity in S rats increased (34 ± 9 percent) during apnea episodes. These results indicate that renal denervation induces elevations of sodium content and urine volume and alters bradycardia and hypotension patterns during total OA in unconscious rats.
Subject(s)
Animals , Male , Rats , Blood Pressure/physiology , Diuresis/physiology , Heart Rate/physiology , Kidney/innervation , Sympathectomy , Sleep Apnea, Obstructive/physiopathology , Acute Disease , Hypotension/physiopathology , Kidney/physiopathology , Natriuresis/physiology , Rats, Wistar , Severity of Illness Index , UrineABSTRACT
O alho (Allium sativum) apresenta várias ações benéficas ao sistema circulatório, tais como diminuição dos níveis de colesterol total, LDL-colesterol e da pressão arterial, além de efeito antioxidante. O objetivo deste estudo foi avaliar o efeito da administração do Allium sativum sobre as alterações da hemodinâmica cardiovascular e estruturais macroscópicas do coração de animais com infarto induzido experimentalmente. Ratos Wistar foram tratados, previamente e após indução do infarto, com homogeneizado de alho na dose de 125mg/Kg/dia durante 21 dias, por via oral (uma semana antes e duas depois do procedimento de infarto). Os grupos controle passaram por cirurgia fictícia (SHAM). Os animais foram divididos em grupos controles e infartados com (SHAMT, INFT; respectivamente) ou sem (SHAM, INF; respectivamente) tratamento com alho. Houve redução da hipertrofia do ventrículo direito (INF=0,75±0,05 vs. INFT=0,61±0,03 mg/Kg; p<0,01), da área de infarto (INF=29,7±4,8% vs. INFT=20,4±1,4%; p<0,05) e regularização dos níveis de pressão arterial sistólica (PAS; INF=100±8 vs. INFT=127±7 mmHg; p<0,05) e média (PAM; INF=94±4 vs. INFT=110±6 mmHg; p<0,01) dos animais INFT comparados com os INF. Houve um menor número de animais mortos após o procedimento de infarto no grupo INFT em relação ao grupo INF (20%, n=2; 45,5%, n=5; respectivamente). Esses achados indicam que o alho tem um importante papel na prevenção e no controle de alterações cardiovasculares, uma vez que houve redução do número de mortes pós-infarto e melhor perfil cardiovascular dos animais INFT.
Garlic (Allium sativum) has several beneficial effects on the cardiovascular system, such as reductions of the levels of total cholesterol, LDL-cholesterol and blood pressure, besides acting as an antioxidant. The aim of this study was to assess the effects of administering Allium sativum on changes in the cardiovascular hemodynamics and macroscopic structure that occur in the hearts of animals with experimentally induced cardiac infarction. Male Wistar rats were treated with homogenized garlic at a dose of 125mg/kg b.w./day for 21 days, given orally for one week before and two weeks after the procedure to induce myocardial infarction. The control group was subjected to a fictitious surgery (SHAM). The animals were divided into control and infarcted groups, treated (SHAMT, INFT) or untreated (SHAM, INF) with garlic. There were reductions in right ventricular hypertrophy (INF=0.75±0.05 vs. INFT=0.61±0.03 mg.kg-1; p<0.01) and infarcted area (INF=29.7±4.8 % vs. INFT=20.4±1.4 %; p<0.05) and regularization of the levels of systolic (SAP; INF=100±8 vs. INFT=127±7 mm Hg; p<0.05) and mean arterial pressure (MAP; INF=94±4 vs. INFT=110±6 mm Hg; p<0.01) in the INFT animals, compared to the INF group. Fewer animals died after the cardiac infarction procedure in the group INFT than in INF (20%, n=2; 45.5%, n=5; respectively). These findings suggest that garlic can have an important role in the prevention and control of cardiovascular abnormalities, since there was a reduction in the number of post-infarction deaths and an improvement of the cardiovascular profile in the INFT animals.