Author: Bełtowski J.
Journal: Journal of Neurology and Neurophysiology, v. 5, p. 243, 2014.
Leptin, an adipose tissue hormone which regulates food intake, is also involved in the pathogenesis of arterial hypertension. Plasma leptin concentration is increased in obese individuals. Chronic leptin administration or transgenic overexpression increases blood pressure in experimental animals, and some studies indicate that plasma leptin is elevated in hypertensive subjects independently of body weight. Leptin has a dose- and time-dependent effect on urinary sodium excretion. High doses of leptin increase Na(+) excretion in the short run; partially by decreasing renal Na(+),K(+)-ATPase (sodium pump) activity. This effect is mediated by phosphatidylinositol 3-kinase (PI3K) and is impaired in animals with dietary-induced obesity. In contrast to acute, chronic elevation of plasma leptin to the level observed in patients with the metabolic syndrome impairs renal Na(+) excretion, which is associated with the increase in renal Na(+),K(+)-ATPase activity. This effect results from oxidative stress-induced deficiency of nitric oxide and/or transactivation of epidermal growth factor receptor and subsequent stimulation of extracellular signal-regulated kinases. Ameliorating "renal leptin resistance" or reducing leptin level and/or leptin signaling in states of chronic hyperleptinemia may be a novel strategy for the treatment of arterial hypertension associated with the metabolic syndrome.
Author: Zapata-Sudo G, da Silva JS, Pereira SL, Souza PJ, de Moura RS, Sudo RT.
Journal: BMC Complementary and Alternative Medicine, v. 14, p. 227, 2014.
Background: This study was designed to evaluate the cardioprotective effects of EuterpeoleraceaMart., popularly known as "açaí", on ratssubjected to myocardialinfarction (MI).
Methods: Hydroalcoholic extracts of açaí were obtained from a decoction of the seeds. Two male Wistar rat groups were delineated: 1) the sham-operated group (control, n = 6), with no surgical amendment, and 2) the MI group (n = 12), in which the anterior descendent coronary artery was occluded during surgery. MI group was divided into two subgroups, in which rats were either treated with hydroalcoholic extract of Euterpeoleracea seeds (100 mg/kg/day p.o.) or received no treatment. Treatment began on the day of surgery, and lasted 4 weeks. Subsequently, rats were subject to an exercise test protocol, hemodynamic evaluation, and histological analysis of the left ventricle. Groups were compared using one-way analysis of variance (ANOVA), followed by Dunnett's test.
Results: The total running distance of sham rats was 1339.0 ± 276.6 m, MI rats was 177.6 ± 15.8 m (P < 0.05), and MI-açaí rats was 969.9 ± 362.2 m. Systolic arterial pressure was significantly decreased in MI rats (86.88 ± 4.62 mmHg) compared to sham rats (115.30 ± 7.24 mmHg; P < 0.05). Açaí treatment prevented a reduction in systolic arterial pressure (130.00 ± 8.16 mmHg) compared to MI rats (P < 0.05). Left ventricular (LV) end-diastolic pressure was significantly augmented in MI rats (17.62 ± 1.21 mmHg) compared to sham rats (4.15 ± 1.60 mmHg; P < 0.05), but was 3.69 ± 2.69 mmHg in açaí-treated rats (P < 0.05 vs. MI). The LV relaxation rate (-dp/dt) was reduced in MI rats compared to the sham group, whereas açaí treatment prevented this reduction. Açaí treatment prevented cardiac hypertrophy and LV fibrosis in MI rats.
Conclusions: Euterpeoleraceatreatment of MI rats prevented the development of exerciseintolerance, cardiac hypertrophy, fibrosis, and dysfunction.
Author: Alencar AK1, Pereira SL1, da Silva FE1, Mendes LV2, Cunha Vdo M2, Lima LM1, Montagnoli TL1, Caruso-Neves C3, Ferraz EB3, Tesch R1, Nascimento JH3, Sant'anna CM4, Fraga CA1, Barreiro EJ1, Sudo RT1, Zapata-Sudo G5.
Journal: International Journal of Cardiology (Print), v. 173, p. 154-162, 2014.
Background: Pulmonary arterial hypertension (PAH) is a disease that results in right ventricular (RV) dysfunction. While pulmonary vascular disease is the primary pathological focus, RV hypertrophy and RV dysfunction are the major determinants of prognosis in PAH. The aim of this study was to investigate the effects of (E)-N'-(3,4-dimethoxybenzylidene)-4-methoxybenzohydrazide (LASSBio-1386), an N-acylhydrazonederivative, on the lung vasculature and RV dysfunction induced by experimental PAH.
Methods: Male Wistar rats were injected with a single dose (60mg/kg, i.p.) of monocrotaline (MCT) and given LASSBio-1386 (50mg/kg, p.o.) or vehicle for 14 days. The hemodynamic, exercise capacity (EC), endothelial nitric oxide synthase (eNOS), adenosine A2A receptor (A2AR), sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA2a), phospholamban (PLB) expression, Ca(2+)-ATPase activity and vascular activity of LASSBio-1386 were evaluated.
Results and conclusions: The RV systolic pressure was elevated in the PAH model and reduced from 49.6 ± 5.0 mm Hg (MCT group) to 27.2 ± 2.1 mm Hg (MCT+LASSBio-1386 group; P<0.05). MCT administration also impaired the EC, increased the RV and pulmonary arteriole size, and promoted endothelial dysfunction of the pulmonary artery rings. In the PAH group, the eNOS, A2AR, SERCA2a, and PLB levels were changed compared with the control; in addition, the Ca(2+)-ATPase activity was reduced. These alterations were related with MCT-injected rats, and LASSBio-1386 had favorable effects that prevented the development of PAH. LASSBio-1386 is effective at preventing endothelial and RV dysfunction in PAH, a finding that may have important implications for ongoing clinical evaluation of A2AR agonists for the treatment of PAH.