Avaliação da função barorreflexa em ratos jovens espontaneamente hipertensos

Valenti, Vítor Engrácia; Ferreira, Celso; Meneghini, Adriano; Ferreira, Marcelo Alves; Murad, Neif; Corrêa, João Antônio; Abreu, Luíz Carlos de; Colombari, Eduardo

doi:10.1590/s0066-782x2009000300009

Cited by 26 publications

(24 citation statements)

References 26 publications

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“…40 Resistance exercise training was able to promote significant improvement only in the bradycardic response. When analyzing the effect of resistance exercise training in rats with metabolic syndrome induced by hypercaloric diet, Valenti et al 41 obtained similar results to ours, demonstrating that this type of exercise is ineffective in improving the tachycardic response, regardless of the experimental model. Thus, the resistance exercise training seems to work mainly with the improvement of the sensitivity of the carotid baroreceptors, since the bradycardic response demonstrates strong correlation with the integrity of carotid sinus.…”

Section: Discussionsupporting

confidence: 80%

The Effect of Physical Resistance Training on Baroreflex Sensitivity of Hypertensive Rats

Gomes¹,

Borges²,

Rossi³

et al. 2017

Arquivos Brasileiros De Cardiologia

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Background:Baroreceptors act as regulators of blood pressure (BP); however, its sensitivity is impaired in hypertensive patients. Among the recommendations for BP reduction, exercise training has become an important adjuvant therapy in this population. However, there are many doubts about the effects of resistance exercise training in this population.Objective:To evaluate the effect of resistance exercise training on BP and baroreceptor sensitivity in spontaneously hypertensive rats (SHR).Method:Rats SHR (n = 16) and Wistar (n = 16) at 8 weeks of age, at the beginning of the experiment, were randomly divided into 4 groups: sedentary control (CS, n = 8); trained control (CT, n = 8); sedentary SHR (HS, n = 8) and trained SHR (HT, n = 8). Resistance exercise training was performed in a stairmaster-type equipment (1.1 × 0.18 m, 2 cm between the steps, 80° incline) with weights attached to their tails, (5 days/week, 8 weeks). Baroreceptor reflex control of heart rate (HR) was tested by loading/unloading of baroreceptors with phenylephrine and sodium nitroprusside.Results:Resistance exercise training increased the soleus muscle mass in SHR when compared to HS (HS 0.027 ± 0.002 g/mm and HT 0.056 ± 0.003 g/mm). Resistance exercise training did not alter BP. On the other hand, in relation to baroreflex sensitivity, bradycardic response was improved in the TH group when compared to HS (HS -1.3 ± 0.1 bpm/mmHg and HT -2.6 ± 0.2 bpm/mmHg) although tachycardia response was not altered by resistance exercise (CS -3.3 ± 0.2 bpm/mmHg, CT -3.3 ± 0.1 bpm/mmHg, HS -1.47 ± 0.06 bpm/mmHg and HT -1.6 ± 0.1 bpm/mmHg).Conclusion:Resistance exercise training was able to promote improvements on baroreflex sensitivity of SHR rats, through the improvement of bradycardic response, despite not having reduced BP.

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Section: Discussionsupporting

confidence: 80%

The Effect of Physical Resistance Training on Baroreflex Sensitivity of Hypertensive Rats

Gomes¹,

Borges²,

Rossi³

et al. 2017

Arquivos Brasileiros De Cardiologia

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“…The abdominal wound healing has not been influenced The pressure level of hypertensive rats in this experiment was lower than that observed in the literature 14,17,20 . This difference in value was probably due to the fact that they were obtained in anesthetized rats rather other authors that had obtained it with the conscious rats.…”

Section: Discussioncontrasting

confidence: 60%

“…The choice of spontaneously hypertensive rats (SHR) is its similarity with essential hypertension in human 14 , whereas in animals with induced hypertension, angiotensin is elevated, which could interfere with the results, since angiotensin II is involved in the healing process, both in a systemic way, as local 15 .…”

Section: Discussionmentioning

confidence: 99%

Influence of arterial hypertension on colonic healing in rats

Ortolan¹,

Biondo-Simões

Fávero³

et al. 2012

Acta Cir. Bras.

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PURPOSE: Evaluation of colonic healing in spontaneously hypertensive rats. METHODS:Fifty male, young and inbred rats were used. Twenty-five Wistar Kyoto rats (WKY) as control and twenty-five spontaneously hypertensive rats (SHR) as an experimental group. Colotomy and bowel suture at 2.5 cm from the peritoneal reflection were performed. All animals were allocated randomly into sub-groups for review at the third, seventh and fourteenth days after surgery.We evaluated the concentration of angiotensin II, the burst pressure, epithelialization, the organization of the tunics of the bowel wall, inflammatory response and collagen deposition. RESULTS:The burst pressure, epithelialization, organization of the tunics and collagen deposition was not significant between groups.The inflammatory reaction was more intense in the control group on the third postoperative day (p=0.023) as the experimental group on the remaining time.CONCLUSION: Systemic arterial hypertension in rats did not influence significantly the healing process of colonic anastomoses.Key words: Wound Healing. Colon. Hypertension. Rats, Inbred SHR. RESUMO OBJETIVO:Avaliar a cicatrização colônica em ratos espontaneamente hipertensos. MÉTODOS:Cinquenta ratos machos, jovens e isogênicos. Vinte e cinco ratos da linhagem Wistar Kyoto (WKY) como controle e vinte e cinco ratos espontaneamente hipertensos (SHR) como grupo experimento. Realizou-se colotomia e colorrafia a 2,5 cm da reflexão peritoneal. Alocaram-se os animais aleatoriamente em sub-grupos para avaliação no terceiro, sétimo e décimo quarto dias de pós-operatório. Foram avaliados a concentração de angiotensina II, a resistência da anastomose à insuflação, a epitelização, a organização das túnicas da parede intestinal, a reação inflamatória e a deposição de colágeno. RESULTADOS:A avaliação da resistência da anastomose, epitelização, organização das túnicas e deposição de colágeno não foi significativa entre os grupos. A reação inflamatória foi mais intensa no grupo controle na avaliação do terceiro dia de pós-operatório (p=0,023) igualando-se ao grupo experimento nos demais tempos. CONCLUSÃO:A hipertensão arterial sistêmica, em ratos, não influenciou de forma significante no processo cicatricial de anastomoses do cólon.Descritores: Cicatrização. Cólon. Hipertensão. Ratos Endogâmicos SHR.

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“…Pulsatile arterial pressure (PAP) of freely moving animals was recorded using an HP-7754A preamplifier (Hewlett Packard, USA) and an acquisition board (MP100A, Biopac Systems Inc, USA) connected to a computer. Mean arterial pressure (MAP) and heart rate (HR) values were derived from the PAP recordings and processed online 12. No signs of pain or discomfort were observed.…”

Section: Methodsmentioning

confidence: 99%

“…There was an interval of at least 15 minutes between infusions to allow the recovery of basal values. We also evaluated bradycardic and tachycardic peaks and HR range, i.e., the difference between bradycardic and tachycardic peaks 12. We separated rats into groups according to baroreflex gain (BG): 1) low bradycardic baroreflex (LB), BG between -1 and -2 bpm/mmHg tested with PE; 2) high bradycardic baroreflex (HB), BG < -2 bpm/mmHg tested with PE; 3) low tachycardic baroreflex (LT), BG between -1 and -2 bpm/mmHg tested with SNP and; 4) high tachycardic baroreflex (HT), BG < -2 bpm/mmHg tested with SNP.…”

Section: Methodsmentioning

confidence: 99%

Strain differences in baroceptor reflex in adult wistar kyoto rats

Valenti

Abreu

Imaizumi

et al. 2010

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OBJECTIVESA subset of normotensive Sprague–Dawley rats show lower baroreflex sensitivity; however, no previous study investigated whether there are differences in baroreflex sensitivity within this subset. Our study compared baroreflex sensitivity among conscious rats of this specific subtype.METHODSMale Wistar Kyoto (WKY) rats (16 weeks old) were studied. Cannulas were inserted into the abdominal aortic artery through the right femoral artery to measure mean arterial pressure (MAP) and heart rate (HR). Baroreflex gain was calculated as the ratio between change in HR and MAP variation (ΔHR/ΔMAP) in response to a depressor dose of sodium nitroprusside (SNP, 50 μg/kg, i.v.) and a pressor dose of phenylephrine (PE, 8 μg/kg, i.v.). Rats were divided into four groups: 1) low bradycardic baroreflex (LB), baroreflex gain (BG) between -1 and -2 bpm/mmHg tested with PE; 2) high bradycardic baroreflex (HB), BG < -2 bpm/mmHg tested with PE; 3) low tachycardic baroreflex (LT), BG between -1 and -2 bpm/mmHg tested with SNP and; 4) high tachycardic baroreflex (HT), BG < -2 bpm/mmHg tested with SNP. Significant differences were considered for p < 0.05.RESULTSApproximately 37% of the rats showed a reduced bradycardic peak, bradycardic reflex and decreased bradycardic gain of baroreflex while roughly 23% had a decreased basal HR, tachycardic peak, tachycardic reflex and reduced sympathetic baroreflex gain. No significant alterations were noted with regard to basal MAP.CONCLUSIONThere is variability regarding baroreflex sensitivity among WKY rats from the same laboratory.

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Avaliação da função barorreflexa em ratos jovens espontaneamente hipertensos

Abstract: SummaryBackground: The literature describes contradictory data regarding the onset of the baroreflex reduction in spontaneously hypertensive rats.

Cited by 26 publications

References 26 publications

The Effect of Physical Resistance Training on Baroreflex Sensitivity of Hypertensive Rats

The Effect of Physical Resistance Training on Baroreflex Sensitivity of Hypertensive Rats

Influence of arterial hypertension on colonic healing in rats

Strain differences in baroceptor reflex in adult wistar kyoto rats

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