Resistance training is one of the most common kind of exercise used nowadays. Long-term high-intensity resistance training are associated with deleterious effects on vascular adjustments. On the other hand, is unclear whether low-intensity resistance training (LI-RT) is able to induce systemic changes in vascular tone. Thus, we aimed to evaluate the effects of chronic LI-RT on endothelial nitric oxide (NO) bioavailability of mesenteric artery and cardiovascular autonomic modulation in healthy rats. Wistar animals were divided into two groups: exercised (Ex) and sedentary (SED) rats submitted to the resistance (40% of 1RM) or fictitious training for 8 weeks, respectively. After LI-RT, hemodynamic measurements and cardiovascular autonomic modulation by spectral analysis were evaluated. Vascular reactivity, NO production and protein expression of endothelial and neuronal nitric oxide synthase isoforms (eNOS and nNOS, respectively) were evaluated in mesenteric artery. In addition, cardiac superoxide anion production and ventricle morphological changes were also assessed. In vivo measurements revealed a reduction in mean arterial pressure and heart rate after 8 weeks of LI-RT. In vitro studies showed an increased acetylcholine (ACh)-induced vasorelaxation and greater NOS dependence in Ex than SED rats. Hence, decreased phenylephrine-induced vasoconstriction was found in Ex rats. Accordingly, LI-RT increased the NO bioavailability under basal and ACh stimulation conditions, associated with upregulation of eNOS and nNOS protein expression in mesenteric artery. Regarding autonomic control, LI-RT increased spontaneous baroreflex sensitivity, which was associated to reduction in both, cardiac and vascular sympathetic modulation. No changes in cardiac superoxide anion or left ventricle morphometric parameters after LI-RT were observed. In summary, these results suggest that RT promotes beneficial vascular adjustments favoring augmented endothelial NO bioavailability and reduction of sympathetic vascular modulation, without evidence of cardiac overload.

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Ginkgo biloba is the most popular phytotherapic agent used worldwide for treatment of several human disorders. However, the mechanisms involved in the protective actions of Ginkgo biloba on cardiovascular diseases remain poorly elucidated. Taking into account recent studies showing beneficial actions of cholinergic signaling in the heart and the cholinergic hypothesis of Ginkgo biloba-mediated neuroprotection, we aimed to investigate whether Ginkgo biloba extract (GBE) promotes cardioprotection via activation of cholinergic signaling in a model of isoproterenol-induced cardiac hypertrophy. Here, we show that GBE treatment (100 mg/kg/day for 8 days, v.o.) reestablished the autonomic imbalance and baroreflex dysfunction caused by chronic β-adrenergic receptor stimulation (β-AR, 4.5 mg/kg/day for 8 days, i.p.). Moreover, GBE prevented the upregulation of muscarinic receptors (M2) and downregulation of β1-AR in isoproterenol treated-hearts. Additionally, we demonstrated that GBE prevents the impaired endothelial nitric oxide synthase activity in the heart. GBE also prevented the pathological cardiac remodeling, electrocardiographic changes and impaired left ventricular contractility that are typical of cardiac hypertrophy. To further investigate the mechanisms involved in GBE cardioprotection in vivo, we performed in vitro studies. By using neonatal cardiomyocyte culture we demonstrated that the antihypertrophic action of GBE was fully abolished by muscarinic receptor antagonist or NOS inhibition. Altogether, our data support the notion that antihypertrophic effect of GBE occurs via activation of M2/NO pathway uncovering a new mechanism involved in the cardioprotective action of Ginkgo biloba.

The acute effects of exercise are generated by alterations in the autonomic nervous system that is mediated through the integration of multiple nuclei of autonomic control. The aim of this study was to evaluate the Fos protein expression on the hypothalamic and medullary areas of cardiovascular control after a single bout of resistance exercise (RE). Were used Wistar rats (250g–300g) divided into two groups: sham (SH) and resistance exercise (RE). The animals performed the RE protocol (10 sets of 10 repetitions with 2 min for recovery) in a squat apparatus with 60% of 1RM. The animals were anesthetized, perfused, the brain was removed and sliced in a cryostat for immunohistochemistry method. The brain sections were subjected to immunofluorescence protocol. Fos protein immunoreactivity increase when compared to SH in the nucleus tractus solitary (RE = 15.3 ± 0.6 vs. SH = 1.6 ± 0.6), in the caudal ventrolateral region of the medulla (RE = 23.3 ± 0.8 vs SH 1.3 ± 0.3) and in the paraventricular nucleus of the hypothalamus (RE = 59.3 ± 4.2 vs SH 1.3 ± 0.3), we showed that after RE there is an intense activation of important brain areas for cardiovascular control during the post exercise period. Suggesting mobilization and possible interaction of specifics nuclei of brain to correct homeostatic changes produced by RE. Research support: CAPES, Fapitec.

An adequate nutritional support is important to ensure a normal development of the fetuses. Changes in the nutritional support during gestation may lead to transitory or permanent structural and functional changes of several organs of the offspring. We aimed to investigate the impact of a high fat diet during the gestation on cardiovascular and autonomic nervous systems (ANS) in the offspring of rats. High fat diet was given from day 1 of gestation until weaning of puppies. Sixty‐day‐old offspring from High Fat Diet dams (HFDD, n= 6) or Normal Diet dams (NDD, n= 6) had femoral arteries surgically assessed for the measurements of heart rate (HR), mean (MAP), systolic (SAP) and diastolic arterial pressure (DAP), and spontaneous baroreflex sensitivity (BRS). To investigate the balance of ANS, we established the high (HF) and low frequency (LF) bands of pulse interval (PI) and LF band of SAP spectrum. HFDD had increased MAP (135 ± 2vs 103± 1 mmHg, p<0.05), SAP (160 ± 3 vs 128 ± 4 mmHg, p<0.05), DAP (111 ± 2vs 91 ± 2 mmHg, p<0.05) and HR (417 ± 23 vs 352 ± 8 bpm, p<0.05) when compared to NDD. After spectral analysis of PI and SAP, LF band of SAP spectrum (6.19 ± 0.84 vs 2.29 ± 0.56 mmHg2, p<0.05) and LF/HF ratio of PI (0.71 ± 0.22 vs 0.14 ± 0.016 p<0.05) was higher in HFDD under spontaneous condition. These findings suggest that high fat diet during pregnancy and lactation leads to autonomic misbalance and hypertension in adult offspring rats.