Journal de l'hypertension : accès libre

Hypertension is a major risk factor of cardiovascular diseases (CVDs), and a most important health problem in developed countries. The rennin-angiotensin-aldosterone system (RAAS) plays a pivotal role in controlling blood pressure or hydro-electrolyte balance. Superoxide production by angiotensinⅡ (AngⅡ) of the classical RAAS pathway is one of the important mechanisms in pathogenesis of CVDs. But in the past decade, many new components of RAAS, such as novel axis consisting of the angiotensin-converting enzyme 2 (ACE2), angiotensin (1-7) (Ang-(1-7)), and the G protein-coupled receptor Mas, has emerged and complicated classical concept of RAAS and pathophysiology of CVDs. In this review we will summarize the recent findings about these new components of RAAS mainly from the viewpoint of molecular mechanism and oxidative stress.

Objectives: To explore the constituent ratio of peripheral blood cells changes in patients with splenomegaly due to posthepatitic cirrhotic portal hypertension and its postoperative prognosis, and to grade the peripheral cytopenias.

Methods: Data of 366 cases of splenomegaly due to posthepatitic cirrhotic portal hypertension were collected and analyzed.

Results: Thirty-six patients (9.8%) had a normal blood cell count and 330 patients had peripheral cytopenias, in which mono-lineage cytopenias accounted for 30% (99/330), bi-lineage cytopenias accounted for 35.8% (118/330) and tri-lineage cytopenias accounted for 34.2% (113/330). There were significant statistical differences (P<0.05) in the postoperative prognostic comparison between mono-lineage cytopenias and multi-linage cytopenias. In the 330 cases of cytopenias, the postoperative prognosis demonstrated significant differences between thrombocytopenia, leukopenia and erythropenia (P<0.05). For the most part, according to the severity of thrombocytopenia, cytopenia was graded as mild, medium and severe, and scored as <2 points, 2-3 points and >3 points, respectively. The prognosis revealed significant differences between the three grades (P<0.05).

Conclusions: Peripheral cytopenias can influence postoperative prognosis. Thrombocytopenia is a major factor influencing postoperative prognosis and grading is of great significance in analyzing the condition of inpatients and guiding their treatment.

Aim: Rapid immersion of a rat’s limbs into 4°C water, a model of cooling stress (CS), can elicit hemodynamic perturbations (CEHP). We have reported that CEHP is highly relevant to the sympathetic activation. This study identifies the role of β-adrenoceptors in CEHP.

Method: Conscious rats were pretreated with the β-adrenoceptor blockade propranolol, (PRO)-only, or following the removal of sympathetic influences using hexamethonium (HEX) or guanethidine (GUA), and then they were subjected to a 10-min CS trial. Cardiovascular indices were monitored via an implanted telemetric device throughout the experimental course. The analyses included measurements of systolic blood pressure (SBP); heart rate (HR); cardiovascular variability (BPV; HRV); spectral coherence at very-low, low, and high frequency regions (VLF: 0.02-0.2 Hz, LF: 0.2-0.6 Hz, and HF: 0.6-3.0 Hz); total power (TP); and dicrotic notch (Dn).

Results: Compared with the vehicle control under the resting (PreCS) and CS conditions respectively, the PROonly (a) increased the powers for VLFBPV, LFBPV, HFBPV, HFHRV, and TPBPV but decreased the power for VLFHRV, the LF/ HF ratio, the Dn under PreCS; (b) increased the powers for LFHRV, HFHRV, and TPHRV, decreased the powers for LFBPV, HFBPV, and TPBPV, the LF/HF ratio, and the Dn, and converted the original negative correlation into positive correlation for VLFHRV with VLFBPV under CS; and (c) weakened the spectral coherence at all frequency regions between BPV and HRV throughout the experimental course. Compared with the control vehicle under PreCS and CS, there were more decreases of SBP (under CS) and HR (under PreCS and CS) after the GUA+PRO than the other interventions (PROonly and/or HEX+PRO). In addition, the effect on spectral powers of the PRO-only was generally altered when the rats were pretreated with HEX or GUA throughout the experimental course.

Significance: Our findings suggest that PRO may exert vascular effects which are dependent on the sympathetic vasodilator tone. Intact sympathetic efferent pathways are required for the inhibition of CEHP by PRO. Besides, the effects of HEX+PRO versus GUA+PRO indicate a functional role of adrenal medulla to release epinephrine to react the cooling stress.

Dietary sodium is a determinant of blood pressure. Modern diets provide excessive amounts of salt, and in developed and developing countries the intake of processed foods with high salt levels is increasing. In order to establish effective nutrition policy, it is necessary to know the quantity of consumed salt as well as identify the main dietary sources of salt. Different methods are currently in use for estimating dietary sodium intake. The use of 24-hour urinary collection to assess sodium intake is considered the most accurate method but involves considerable burden for participants. The use of the spot urine method has been proposed as an alternative however in not recommended without calibration methodology. Sodium estimates based on dietary surveys include several methods such the 24-hour dietary recall, the food frequency questionnaire, and the diet record, with often under-estimates intake due to under-reporting and difficulties quantifying sodium in concentration discretionary salt and recipes. Food compositions databases and nutritional softwares can be used to assess sodium consumption. More research is necessary to improve nutritional epidemiological tools for sodium intake

Objective: To assess the relationship among systolic blood pressure variation (BPV), inflammation and arterial rigidity in essential hypertension. Methods: This study enrolled 80 patients with essential hypertension, who were started on blood pressure control treatment with medications and lifestyle modification, and 18 normotensive healthy controls. At enrollment and 1-year follow-up, systolic BPV was evaluated by coefficient of variation (CV) in ambulatory blood pressure monitoring; arterial rigidity by brachial-ankle pulse wave velocity (ba-PWV) using ColinVP-1000; and inflammation by high-sensitivity plasma C-reactive protein (hs-CRP) level using rate nephelometry; electrocardiography, blood glucose, lipid profile, creatinine, blood urea nitrogen, and liver and renal function also were assessed. Results: There were no significant differences in demographics, clinical or biochemical profiles between patients and normotensive controls, except for blood pressure at enrollment but not 1-year follow-up, reflecting effectiveness of blood pressure control measures, with significant decreases in CV, ba-PWV and hs-CRP between enrollment and 1-year follow-up in hypertensive patients; change in CV significantly correlated with those in ba-PWV and hs-CRP (both P<0.001, adjusted by SBP d). Conclusion: The effect of systolic BPV on arterial rigidity could be mediated by its influence on the onset and progression of inflammation.