Abstract Fibromyalgia (FM) is characterized by chronic non-inflammatory widespread pain (CWP) and changes in sympathetic function. In attempt to elucidate the pathophysiological mechanisms of FM we ...used a well-established CWP animal model. We aimed to evaluate changes in cardiac autonomic balance and baroreflex function in response to CWP induction in rats. CWP was induced by two injections of acidic saline (pH 4.0, n = 8) five days apart into the left gastrocnemius muscle. Control animals were injected twice with normal saline (pH 7.2, n = 6). One day after the second injection of acidic saline or normal saline, the animals had pulse interval (PI) and systolic arterial pressure (SAP) variability, and spontaneous baroreflex sensitivity (BRS) evaluated. After induction of CWP, there was an increase of power in the low frequency (LF) band of PI spectrum (12.75 ± 1.04 nu), a decrease in the high frequency (HF) band (87.25 ± 1.04 nu) and an increase of LF/HF ratio (0.16 ± 0.01), when compared to control animals (7.83 ± 1.13 nu LF; 92.16 ± 1.13 nu HF; 0.08 ± 0.01 LF/HF). In addition, there was an increase of power in the LF band of SAP spectrum (7.93 ± 1.39 mmHg2 ) when compared to control animals (2.97 ± 0.61 mmHg2 ). BRS was lower in acidic saline injected rats (0.59 ± 0.06 ms/mmHg) when compared to control animals (0.71 ± 0.03 ms/mmHg). Our results showed that induction of CWP in rats shifts cardiac sympathovagal balance towards sympathetic predominance and decreases BRS. These data corroborate findings in humans with FM.
Fibromyalgia (FM) is characterized by chronic non‐inflammatory widespread pain (CWP). Changes in sympathetic function occur in patients with FM. In attempt to elucidate the pathophysiology mechanisms ...of FM we used an animal model that mimics FM symptoms. We aimed to evaluate changes in the autonomic balance as well as baroreflex function in response to CWP induction in rats. 14 wistar male rats with (GSA, n=8) and without (GSN, n=6) the induction of CWP were used. CWP was induced by two injections of pH 4.0 saline into the gastrocnemius muscle. 24 hours after the second injection of acid or neutral saline the animals were instrumentated to record blood pressure (BP), analyze variability of pulse interval (IP) and BP, and analyze spontaneous barorefex sensibility (BRS). After induction of CWP, there was an increase in the oscillations (IP variability) at LF (11 ± 1.18), a decrease in the oscillations at HF (89 ± 1.18) which results in an increase in the LF/HF ratio (0.14 ± 0.02) when compared to controls (7 ± 0.4 LF; 93 ± 0.4 HF; 0.08 ± 0.00 LF/HF;). There was no difference in BP oscillations in LF between groups (50 ± 3.9% GSA vs 38 ± 5.5% GSN, p= 0.09). BRS was reduced when compared to controls (11,87 ± 1,42 mmHg/s GSA vs 17,45 ± 3,10 mmHg/s GSN, p= 0.04) Our results showed that induction of CWP in rats shifts the autonomic balance towards sympathetic tone as well as decrease the BRS, conditions that are also seen in humans with FM.
The prevalence of cardiovascular diseases including hypertension increases dramatically in women after menopause, however the mechanisms involved remain incompletely understood. Oxytocinergic ...(OTergic) neurons are largely present within the paraventricular nucleus of the hypothalamus (PVN). Several studies have shown that OTergic drive from PVN to brainstem increases baroreflex sensitivity and improves autonomic control of the circulation. Since preautonomic PVN neurons express different types of estrogen receptors, we hypothesize that ovarian hormone deprivation causes baroreflex impairment, autonomic imbalance and hypertension by negatively impacting OTergic drive and oxytocin levels in pre-autonomic neurons. Here, we assessed oxytocin gene and protein expression (qPCR and immunohistochemistry) within PVN subnuclei in sham-operated and ovariectomized Wistar rats. Conscious hemodynamic recordings were used to assess resting blood pressure and heart rate and the autonomic modulation of heart and vessels was estimated by power spectral analysis. We observed that the ovarian hormone deprivation in ovariectomized rats decreased baroreflex sensitivity, increased sympathetic and reduced vagal outflows to the heart and augmented the resting blood pressure. Of note, ovariectomized rats had reduced PVN oxytocin mRNA and protein expression in all pre-autonomic PVN subnuclei. Furthermore, reduced PVN oxytocin protein levels were positively correlated with decreased baroreflex sensitivity and negatively correlated with increased LF/HF ratio. These findings suggest that reduced oxytocin expression in OTergic neurons of the PVN contributes to the baroreflex dysfunction and autonomic dysregulation observed with ovarian hormone deprivation.
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Insulin resistance (IR) precedes clinical manifestation of diseases such as diabetes mellitus and hypertension and is associated with increased sympathetic modulation. However, in the ...dexamethasone‐induced IR no changes have been noted in heart rate (HR). Therefore, we evaluated the heart chronotropic competence through beta‐adrenergic agonist stimulation in dexamethasone‐induced IR. Young male rats were divided into two groups: Control (CT)(n=6) and IR (n=6). CT and IR groups received vehicle or dexamethasone (DEX) (2mg/kg/day) i.p during seven days, respectively. To confirm Insulin resistance, insulin tolerance test (ITT) was performed after 6h fasted. Left femoral artery and vein were cannulated to measure blood pressure (2 kHz sampling rate) and isoproterenol (4μg/kg) administration respectively, 24h before evaluation. IR group presented attenuated decrease in glycaemia during ITT (CT: 42.5 ± 5 vs IR: 110.7 ± 14), hypertension (CT: 100 ± 2 vs IR: 135 ± 9 mmHg) without heart rate changes. In addition, increased cardiac sympathetic modulation by spectral analysis (LF/HF ratio CT: 0.52 ± 0.03 vs IR: 0.69 ± 0.04 un). After beta‐adrenergic stimulation IR group showed lower variation from basal level (ΔHR CT: 179 ± 4 vs IR: 78 ± 5 bpm). The reduction in heart chronotropic competence observed in this IR model could be a defense mechanism due cardiac sympathetic over activity.
Support or Funding Information
Fapitec‐SE; CAPES; CNPq.
Resumo: Introdução e objetivos: O consumo da dieta ocidental está associado ao surgimento de doenças cardiovasculares. O treinamento de resistência (TR) tem sido utilizado no tratamento destas ...doenças. O objetivo deste trabalho foi avaliar o efeito do TR sobre as alterações cardiometabólicas na prole de ratas expostas a dieta ocidental no período perinatal. Métodos: Ratas Wistar receberam dieta controle ou ocidental durante a gravidez e lactação. Os filhotes foram divididos em três grupos: Controle (C), dieta ocidental sedentário (OCS) e dieta ocidental + TR (OCTR). Aos 60 dias de vida, os animais iniciaram o protocolo de TR realizado cinco vezes por semana durante quatro semanas. Ao fim, foi registrada pressão arterial para análise da variabilidade da frequência cardíaca e sensibilidade do barorreflexo (SBR). Amostras de sangue foram coletadas para análise bioquímica. Resultados: O TR foi capaz de reduzir a pressão arterial, a modulação simpática vascular e aumentar a SBR. Houve melhoria no perfil bioquímico, com redução na glicemia de jejum, colesterol total e lipoproteínas de baixa densidade, além de aumento das lipoproteínas de alta densidade. Conclusão: O TR promoveu adaptações benéficas ao sistema cardiovascular, mediadas por ajustes nos mecanismos de controle autonômico e perfil bioquímico dos animais expostos à dieta ocidental no período perinatal. Abstract: Introduction and objectives: Consumption of a Western diet during the perinatal period is associated with development of cardiovascular disease. Resistance training (RT) has been used to treat cardiovascular disorders. The aim of this work was to assess the effect of RT on cardiometabolic disorders in rats exposed to a Western diet in the perinatal period. Methods: Female Wistar rats were fed with control or Western diet during pregnancy and lactation. The pups were divided into three groups: Control (C), Western Diet Sedentary (WDS) and Western Diet + RT (WDRT). At 60 days of age, all animals started the RT protocol (five times a week for four weeks). At the end, blood pressure was recorded for analysis of heart rate variability and baroreflex sensitivity (BRS). Blood samples were collected for biochemical analysis. Results: RT reduced blood pressure and vascular sympathetic modulation and increased BRS. There were improvements in biochemical profile, with reductions in fasting blood glucose, total cholesterol and low‐density lipoprotein, and an increase in high‐density lipoprotein. Conclusion: RT led to beneficial adaptations in the cardiovascular system, mediated by changes in the mechanisms of autonomic control and biochemical profile of animals exposed to a Western diet in the perinatal period. Palavras‐chave: Treinamento de resistência, Sistema nervoso autônomo, Dieta ocidental, Keywords: Resistance training, Autonomic nervous system, Western diet
Consumption of a Western diet during the perinatal period is associated with development of cardiovascular disease. Resistance training (RT) has been used to treat cardiovascular disorders. The aim ...of this work was to assess the effect of RT on cardiometabolic disorders in rats exposed to a Western diet in the perinatal period.
Female Wistar rats were fed with control or Western diet during pregnancy and lactation. The pups were divided into three groups: Control (C), Western Diet Sedentary (WDS) and Western Diet + RT (WDRT). At 60 days of age, all animals started the RT protocol (five times a week for four weeks). At the end, blood pressure was recorded for analysis of heart rate variability and baroreflex sensitivity (BRS). Blood samples were collected for biochemical analysis.
RT reduced blood pressure and vascular sympathetic modulation and increased BRS. There were improvements in biochemical profile, with reductions in fasting blood glucose, total cholesterol and low-density lipoprotein, and an increase in high-density lipoprotein.
RT led to beneficial adaptations in the cardiovascular system, mediated by changes in the mechanisms of autonomic control and biochemical profile of animals exposed to a Western diet in the perinatal period.
AbstractIntroduction and ObjectivesConsumption of a Western diet during the perinatal period is associated with development of cardiovascular disease. Resistance training (RT) has been used to treat ...cardiovascular disorders. The aim of this work was to assess the effect of RT on cardiometabolic disorders in rats exposed to a Western diet in the perinatal period.MethodsFemale Wistar rats were fed with control or Western diet during pregnancy and lactation. The pups were divided into three groups: Control (C), Western Diet Sedentary (WDS) and Western Diet+RT (WDRT). At 60 days of age, all animals started the RT protocol (five times a week for four weeks). At the end, blood pressure was recorded for analysis of heart rate variability and baroreflex sensitivity (BRS). Blood samples were collected for biochemical analysis.ResultsRT reduced blood pressure and vascular sympathetic modulation and increased BRS. There were improvements in biochemical profile, with reductions in fasting blood glucose, total cholesterol and low-density lipoprotein, and an increase in high-density lipoprotein.ConclusionRT led to beneficial adaptations in the cardiovascular system, mediated by changes in the mechanisms of autonomic control and biochemical profile of animals exposed to a Western diet in the perinatal period.
O consumo da dieta ocidental está associado ao surgimento de doenças cardiovasculares. O treinamento de resistência (TR) tem sido utilizado no tratamento destas doenças. O objetivo deste trabalho foi ...avaliar o efeito do TR sobre as alterações cardiometabólicas na prole de ratas expostas a dieta ocidental no período perinatal.
Ratas Wistar receberam dieta controle ou ocidental durante a gravidez e lactação. Os filhotes foram divididos em três grupos: Controle (C), dieta ocidental sedentário (OCS) e dieta ocidental+TR (OCTR). Aos 60 dias de vida, os animais iniciaram o protocolo de TR realizado cinco vezes por semana durante quatro semanas. Ao fim, foi registrada pressão arterial para análise da variabilidade da frequência cardíaca e sensibilidade do barorreflexo (SBR). Amostras de sangue foram coletadas para análise bioquímica.
O TR foi capaz de reduzir a pressão arterial, a modulação simpática vascular e aumentar a SBR. Houve melhoria no perfil bioquímico, com redução na glicemia de jejum, colesterol total e lipoproteínas de baixa densidade, além de aumento das lipoproteínas de alta densidade.
O TR promoveu adaptações benéficas ao sistema cardiovascular, mediadas por ajustes nos mecanismos de controle autonômico e perfil bioquímico dos animais expostos à dieta ocidental no período perinatal.
Consumption of a Western diet during the perinatal period is associated with development of cardiovascular disease. Resistance training (RT) has been used to treat cardiovascular disorders. The aim of this work was to assess the effect of RT on cardiometabolic disorders in rats exposed to a Western diet in the perinatal period.
Female Wistar rats were fed with control or Western diet during pregnancy and lactation. The pups were divided into three groups: Control (C), Western Diet Sedentary (WDS) and Western Diet + RT (WDRT). At 60 days of age, all animals started the RT protocol (five times a week for four weeks). At the end, blood pressure was recorded for analysis of heart rate variability and baroreflex sensitivity (BRS). Blood samples were collected for biochemical analysis.
RT reduced blood pressure and vascular sympathetic modulation and increased BRS. There were improvements in biochemical profile, with reductions in fasting blood glucose, total cholesterol and low‐density lipoprotein, and an increase in high‐density lipoprotein.
RT led to beneficial adaptations in the cardiovascular system, mediated by changes in the mechanisms of autonomic control and biochemical profile of animals exposed to a Western diet in the perinatal period.
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Studies have shown that hormonal, metabolic and nutritional disorders during the early phase of development and/or in the gestation may lead to transitory or permanent structural and ...functional changes of several organs of the offspring. Our aim was to investigate the impact of high fat diet during the gestation and lactation on biochemical parameters in the offspring of rats. High fat diet was given from day 1 of gestation until weaning of puppies. The biochemical evaluation was performed at 30, 60 and 90 days after birth from High Fat Diet dams (HFDD, n= 6) or Normal Diet dams (NDD, n= 6). Animals from HFDD group presented hyperglycemia starting from day 30 (119 ± 1.6 vs 94.03 ± 2 mg/dl, p<0.05) and LDL (45 ± 7 vs 23 ± 4 mg/dl, p<0.05). In the day 60 OHFD showed difference at TAG ( 61 ± 3 vs 51 ± 1 mg/dl, p<0.05), TC ( 98 ± 5 vs 75 ± 2 mg/dl, p<0.05), VLDL ( 13 ± 0.69 vs 10 ± 0.2 mg/dl, p<0.05) and decrease HDL (42 ± 3 vs 61.42 ± 4 mg/dl, p<0.05). These findings suggest that high fat diet during pregnancy and lactation leads dyslipidemia in adult offspring rats.
Support: CNPq, Fapitec and CAPES
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