An improved strategy for evaluating the extent of chronic arterial baroreceptor denervation in conscious rats

There is no index or criterion of aortic barodenervation, nor can we differentiate among rats that have suffered chronic sham, aortic or sino-aortic denervation. The objective of this study was to develop a procedure to generate at least one quantitative, reproducible and validated index that precisely evaluates the extent of chronic arterial barodenervation performed in conscious rats. Data from 79 conscious male Wistar rats of about 65-70 days of age with diverse extents of chronic arterial barodenervation and used in previous experiments were reanalyzed. The mean arterial pressure (MAP) and the heart rate (HR) of all rats were measured systematically before (over 1 h) and after three consecutive iv bolus injections of phenylephrine (PHE) and sodium nitroprusside (SNP). Four expressions of the effectiveness of barodenervation (MAP lability, PHE ratio, SNP ratio, and SNP-PHE slope) were assessed with linear fixed models, three-level average variance, average separation among levels, outlier box plot analysis, and overlapping graphic analysis. The analysis indicated that a) neither MAP lability nor SNP-PHE slope was affected by the level of chronic sodium intake; b) even though the Box-Cox transformations of both MAP lability [transformed lability index (TLI)] and SNP-PHE slope [transformed general sensitivity index (TGSI), {((3-(ΔHRSNP-ΔHRPHE/ΔMAPSNP-ΔMAPPHE))-0.4-1)/-0.04597}] could be two promising indexes, TGSI proved to be the best index; c) TLI and TGSI were not freely interchangeable indexes for this purpose. TGSI ranges that permit differentiation between sham (10.09 to 11.46), aortic (8.40 to 9.94) and sino-aortic (7.68 to 8.24) barodenervated conscious rats were defined.

Reference value of brachial-ankle pulse wave velocity for the eastern Chinese population and potential influencing factors

The present study was conducted to obtain reference values for brachial-ankle pulse wave velocity (baPWV) and to evaluate influencing factors of baPWV according to gender. Using automatic devices, baPWV was measured simultaneously in 2095 subjects. A total of 647 healthy subjects, none of whom presented atherosclerotic risk factors, were analyzed in the present study. Two different statistical methods were used to obtain reference values for baPWV according to subject gender and age. The association between baPWV value and gender, as well as other features, were analyzed. For male subjects, multiple stepwise analysis showed that age, systolic blood pressure (SBP), heart rate (HR), and plasma levels of triglycerides (TG) were independent predictors of baPWV. For female subjects, age, SBP, HR, and plasma levels of uric acid (UA) were independent predictors of baPWV. In male subjects, the upper limits of baPWV values were 1497.43/1425.00, 1518.67/1513.25, 1715.97/1726.50, 1925.20/1971.90, and 2310.18/2115.00 cm/s, obtained using two different statistical methods for the age ranges of 30-39, 40-49, 50-59, 60-69, and 70 and older, respectively. For females, the upper limits of baPWV values were 1426.70/1411.13, 1559.15/1498.95, 1733.50/1739.00, 1958.63/1973.78, and 2720.80/2577.00 cm/s for the age ranges of 30-39, 40-49, 50-59, 60-69, and 70 and older, respectively. Aging is the most important influencing factor for baPWV value and its effect is more prominent in females. The reference values of baPWV according to age and gender may be useful for the clinical diagnosis and preventive therapy of cardiovascular diseases.

Effects of immobilization and remobilization on the ankle joint in Wistar rats

A sprained ankle is a common musculoskeletal sports injury and it is often treated by immobilization of the joint. Despite the beneficial effects of this therapeutic measure, the high prevalence of residual symptoms affects the quality of life, and remobilization of the joint can reverse this situation. The aim of this study was to analyze the effects of immobilization and remobilization on the ankle joint of Wistar rats. Eighteen male rats had their right hindlimb immobilized for 15 days, and were divided into the following groups: G1, immobilized; G2, remobilized freely for 14 days; and G3, remobilized by swimming and jumping in water for 14 days, performed on alternate days, with progression of time and a series of exercises. The contralateral limb was the control. After the experimental period, the ankle joints were processed for microscopic analysis. Histomorphometry did not show any significant differences between the control and immobilized/remobilized groups and members, in terms of number of chondrocytes and thickness of the articular cartilage of the tibia and talus. Morphological analysis of animals from G1 showed significant degenerative lesions in the talus, such as exposure of the subchondral bone, flocculation, and cracks between the anterior and mid-regions of the articular cartilage and the synovial membrane. Remobilization by therapeutic exercise in water led to recovery in the articular cartilage and synovial membrane of the ankle joint when compared with free remobilization, and it was shown to be an effective therapeutic measure in the recovery of the ankle joint.

Effect of salt intake and potassium supplementation on brachial-ankle pulse wave velocity in Chinese subjects: an interventional study

Accumulating evidence has suggested that high salt and potassium might be associated with vascular function. The aim of this study was to investigate the effect of salt intake and potassium supplementation on brachial-ankle pulse wave velocity (PWV) in Chinese subjects. Forty-nine subjects (28-65 years of age) were selected from a rural community of northern China. All subjects were sequentially maintained on a low-salt diet for 7 days (3.0 g/day NaCl), a high-salt diet for an additional 7 days (18.0 g/day NaCl), and a high-salt diet with potassium supplementation for a final 7 days (18.0 g/day NaCl+4.5 g/day KCl). Brachial-ankle PWV was measured at baseline and on the last day of each intervention. Blood pressure levels were significantly increased from the low-salt to high-salt diet, and decreased from the high-salt diet to high-salt plus potassium supplementation. Baseline brachial-ankle PWV in salt-sensitive subjects was significantly higher than in salt-resistant subjects. There was no significant change in brachial-ankle PWV among the 3 intervention periods in salt-sensitive, salt-resistant, or total subjects. No significant correlations were found between brachial-ankle PWV and 24-h sodium and potassium excretions. Our study indicates that dietary salt intake and potassium supplementation, at least in the short term, had no significant effect on brachial-ankle PWV in Chinese subjects.