Acute effect of ambient ozone on heart rate variability in healthy elderly subjects

Acute ambient ozone (O(3)) exposure is associated with the increased mortality and morbidity of cardiovascular diseases. The dysfunction of cardiac autonomic nervous system (ANS), indicated by the disturbed heart rate variability (HRV), may be the most important underlying mechanism. Previous studies reported the heterogeneous associations between O(3) within several hours' exposure and HRV on general elderly subjects, in which poor surrogate of exposure evaluation and different health status of the subjects may be responsible for the heterogeneous associations. No studies were found focusing on the O(3)-mediated HRV effects within several minutes' exposure on healthy older subjects until recently. We measured the real-time 5-min ambient O(3) concentration and HRV frequency indices in 20 healthy elderly subjects in two surveys, with the 1st and 2nd survey in summer and winter, respectively. Mixed-linear model was used to evaluate the associations between the ambient 5-min average O(3) and concurrent 5-min HRV frequency indices measured during the outdoor period. After adjusting the co-pollutants (ambient PM(2.5) and nitrogen oxides concentrations) and subject characteristics, high frequency (HF) changed -4.87% (95% CI -8.62 to -0.97%) per 10?ppb increment of O(3), whereas decreased low frequency (LF) and increased LFHFR were found to be marginally associated with the elevated O(3) (P values were 0.092 and 0.069). We concluded that the ambient O(3) exert transient decrease effects on HRV, which may induce acute cardiac events.     

High-fat, high-sucrose, and high-cholesterol diets accelerate tumor growth and metastasis in tumor-bearing mice

Epidemiological studies indicate that the risk factors for the development of various cancers are closely associated with metabolic symptoms such as obesity, hyperlipidemia, and insulin resistance caused by the excess consumption of high-calorie diets. However, the mechanisms of tumor growth and metastasis caused by feeding a high-calorie diet have not been clarified yet in tumor-bearing mice. In this study, we examined the effects of a high-fat (HF), a high-sucrose (HS), a high-cholesterol (HC) or a low-fat/low-sucrose (LF/LS) diet on tumor growth and metastasis in tumor-bearing mice. Angiogenic factors such as plasma leptin and monocyte chemoattractant protein-1 (MCP-1) were increased after the implantation of tumors, whereas conversely, an antiangiogenic factor, adiponectin, was reduced after the implantation of tumors in mice fed the HF, the HS, or the HC diet compared to LF/LS diet. Furthermore, we found that vascular endothelial growth factor, hypoxia inducible factor-1alpha and MCP-1 expression levels in tumors of mice fed the HF, the HS, or the HC diet were increased compared to those of mice fed the LF/LS diet. These findings suggest that the acceleration of tumor growth and metastasis by feeding the 3 diets may be due to the increase of angiogenic factors and the reduction of antiangiogenic factors.     

High-Fat,High-Sucrose,and High-Cholesterol Diets Accelerate Tumor Growth and Metastasis in Tumor-Bearing Mice

Epidemiological studies indicate that the risk factors for the development of various cancers are closely associated with metabolic symptoms such as obesity, hyperlipidemia, and insulin resistance caused by the excess consumption of high-calorie diets. However, the mechanisms of tumor growth and metastasis caused by feeding a high-calorie diet have not been clarified yet in tumor-bearing mice. In this study, we examined the effects of a high-fat (HF), a high-sucrose (HS), a high-cholesterol (HC) or a low-fat/low-sucrose (LF/LS) diet on tumor growth and metastasis in tumor-bearing mice. Angiogenic factors such as plasma leptin and monocyte chemoattractant protein-1 (MCP-1) were increased after the implantation of tumors, whereas conversely, an antiangiogenic factor, adiponectin, was reduced after the implantation of tumors in mice fed the HF, the HS, or the HC diet compared to LF/LS diet. Furthermore, we found that vascular endothelial growth factor, hypoxia inducible factor-1α and MCP-1 expression levels in tumors of mice fed the HF, the HS, or the HC diet were increased compared to those of mice fed the LF/LS diet. These findings suggest that the acceleration of tumor growth and metastasis by feeding the 3 diets may be due to the increase of angiogenic factors and the reduction of antiangiogenic factors.     

Increasing Vegetable Diversity Consumption Impacts the Sympathetic Nervous System Activity in School-Aged Children

Evidence about the impact of vegetable and fruit diversity consumption on the autonomic nervous system (ANS) functioning is scarce. In this cross-sectional study (513 participants, 49.9% girls aged 7 to 12 years), we evaluated the association between vegetable and fruit diversity consumption and the ANS in school-aged children. Dietary intake was collected using a single 24-h recall questionnaire. Fruit and vegetable diversity consumption was estimated by summing up all the different individual vegetables and fruits consumed in one day. Pupillometry was used to assess pupillary light response, which evaluated the ANS activity. Adjusted linear regressions estimated the association between vegetable and fruit diversity consumption with pupillary light response measures. There was a positive and significant association between vegetable diversity consumption and the average dilation velocity, a measure related to the sympathetic nervous system activity (β-coefficient = 0.03, 95%CI: 0.002; 0.07). Our findings show that vegetable diversity consumption is associated with the ANS response, a possible early link between diet and health in school-aged children.     

Autonomic nervous system activity under rotational shift programs: effects of shift period and gender

Rotational shifts perturb homeostatic mechanisms in a sexually dimorphic way and may compromise the activity of the autonomic nervous system during day- and night-shifts. Heart rate variability (HRV) is a non-invasive measure to assess autonomic control of the heart. Our aim in this study was to assess HRV by short-term continuous electrocardiogram in female (n=40, average age: 31, average working year: 7) and male (n=40, average age: 29, average working year: 6) nurses under rotational shift programs, HRV is derived from short-term electrocardiogram recordings, carried out both at day- and night -shifts, and included time-domain [e.g., standard deviation of NN intervals, SDNN (ms); percentage of successive RR intervals that differ by more than 50 ms, pNN50 (%); root mean square of successive RR interval differences, RMSSD (ms)] and frequency-domain [very low frequency, VLF; low frequency, LF; high frequency, HF; LF/HF] parameters. Heart rates were similar across the groups but males had lower SDNN (p=0.020), RMSSD (p=0.001). pNN50 (p=0.001), VLF (p=0.048) and HF (p=0.001) but had higher LF/HF ratio (p=0.000) than females. In general, these parameters did not differ between day- and night-shifts (p>0.05). Lower HRV parameters and higher LF/HF in males suggest that they may be under greater threat for disease progression.     

健步走锻炼对原发性高血压病患者自主神经功能的影响

[目的]探讨高血压病的自主神经发病机理,以及有氧运动防治高血压病的自主神经机制。[方法]25名61～65岁健康妇女作为正常对照组,50名61～65岁高血压病妇女,随机分为高血压运动组和高血压对照组,高血压运动组进行健步走锻炼12周（每周3次,每次1 h,运动强度46%～60?）。实验开始前后,测试血浆去甲肾上腺素（NE）、肾上腺素（E）和血清乙酰胆碱酯酶（ACHE）活性,以及心率变异性（HRV）。[结果]实验前,与正常对照组相比,高血压病患者血浆NE、E增高,HRV参数LF、LF/HF上升,HF下降。健步走锻炼3个月后,血浆NE、HRV参数LF和LF/HF下降且低于高血压对照组,HF上升且高于高血压对照组,并且各指标趋于接近正常对照组水平。HRV测试过程中,各组在安静状态下没有显示的差异,可在运动状态和深呼吸状态下得以显现。[结论]自主神经失衡与高血压病发病机理存在一定的联系,健步走锻炼可通过纠正高血压病患者的自主神经失衡,达到治疗高血压病的目的。在动态负荷状态下测试HRV可实现对自主神经功能较为全面准确的评价。     

The combined effects of capsaicin, green tea extract and chicken essence tablets on human autonomic nervous system activity

The purpose of this study was to investigate whether combined capsaicin, green tea, and chicken essence tablets (CCGC) enhance human autonomic nervous activities (ANS) associated with thermogenic sympathetic activity without any adverse effect on the cardiac depolarization-repolarization period. Six healthy males (25.2 +/-1.7 y) volunteered for this experiment. Autonomic nervous activities were examined 5-min at rest per 30-min for total 1.5 h after consuming chicken or CCGC or placebo tablets at random on separate days. Using heart rate variability power spectral analysis, we assessed human autonomic nervous activities. In comparison to chicken essence or placebo tablets, it was observed that the consumption of CCGC significantly increased human autonomic nervous activities [Total power representing over-all ANS activity; CCGC trial 160.2 (50.0) vs. placebo 92.8 (53.3)%, p < 0.05; VLF, very low-frequency power associated with thermogenic sympathetic activity: CCGC trial 235.5 (101.7) vs. chicken 130.5 (52.9)%, p < 0.05; LF, low frequency power representing combined sympatho-vagal activity: CCGC trial 199.8 (59.8) vs. placebo 120.6 (49.2)%, p < 0.05] at 60-min and 90-min. There were no significant differences in heart rate corrected cardiac recovery time (RTc) or QT interval (QTc). In conclusion, the consumption of CCGC enhances thermogenic sympathetic activity compared to that of chicken essence or placebo tablets. Therefore, these results suggest that combined capsaicin, green tea, and chicken essence tablets may be a beneficial food ingredient improving human autonomic nervous activities, particularly thermogenic sympathetic activity as a modulator of energy metabolism without any adverse effects on cardiac electrical stability.     

Assessment of autonomic nervous activity in hand-arm vibration syndrome patients using time- and frequency-domain analyses of heart rate variation

Objectives: The aim of the present study was to non-invasively assess autonomic nervous activity, using time- and frequency-domain analyses of heart rate variation (HRV), and to investigate the relationship between indices of HRV and duration of exposure to vibration (DEV), time since retirement from work involving vibration (TR) and time undergoing treatment (TT) in a group of patients with hand-arm vibration syndrome (HAVS). Subjects and methods: Twenty one HAVS patients who were no longer exposed to vibration and were undergoing standard treatment for HAVS, and 10 healthy control subjects, similar to the patients in age, height, weight and number of current smokers and drinkers, volunteered for this study. Indices of HRV [time-domain indices (the mean of R-R intervals, standard deviation and coefficient of variation) and normalized units of frequency-domain indices [low frequency (LF) and high frequency (HF) components], indicating parasympathetic nervous activity, were calculated from 2 min electrocardiographic data recorded during spontaneous breathing by subjects in supine rest. Results: The LF and HF components of the patients were significantly lower than those of the healthy controls (P < 0.05). When Pearson correlation analysis was applied for the patient group, using indices of HRV with age, weight, height, DEV, TR and TT, the LF components positively related to TR and TT (P < 0.01). The patients were thus divided into three groups as follows, according to TR: group A (≤1 year), group B (>1 to <5 years) and group C (≥5 to ≤10  years), or according to TT: group X (≤1 year), group Y (>1 to <5 years) and group Z (≥5 to ≤10  years). The LF components of the groups A and X were significantly lower than that of the healthy controls (P < 0.01). The HF components of the groups A and X were also significantly lower than that of the healthy controls (P < 0.05). Conclusions: The findings of the present study indicate decreased cardiac parasympathetic activity in the HAVS patients in comparison to the healthy controls. The TT and TR significantly influenced the HRV results in these patients; however, the DEV did not. The findings also indicate that treatment and cessation of exposure to vibration might have a beneficial effect on the cardiac parasympathetic activity in HAVS patients. Received: 18 March 1999 / Accepted: 14 June 1999     

Effect of salt intensity in soup on ad libitum intake and on subsequent food choice

The effect of salt intensity on ad libitum intake of tomato soup was investigated when soup was served as a first course and as a second course. Also the effect of salt intensity in soup on subsequent sweet vs. savory choice of sandwich fillings was investigated. Forty-three healthy subjects consumed ad libitum a low-salt (LS), ideal-salt (IS) and high-salt (HS) tomato soup in both meal settings. The salt concentrations were selected on an individual basis, in a way that IS was most pleasant and LS and HS were similar in pleasantness. The ad libitum intake of IS soup was higher than that of LS and HS soup, and the ad libitum intake of LS soup was higher than that of HS soup. The meal setting, soup as a first or as a second course, did not affect ad libitum intake. Salt intensity in soup did not predict sweet vs. savory choice of fillings in grams or energy, although most sodium from fillings was consumed after intake of HS soup. In conclusion, a higher salt intensity lead to lower ad libitum intake of soup similar in palatability (LS vs. HS). In addition, salt intensity in soup does not predict sweet vs. savory food choice.     

Influence of CoQ10 on autonomic nervous activity and energy metabolism during exercise in healthy subjects

Background: CoQ10 has come to be widely used as a dietary supplement, and daily intake of it has increased in recent years. CoQ10 is produced in all living organisms and is an essential coenzyme for energy synthesis in the mitochondria and an important scavenger of reactive oxygen species. Objective: This is a randomized, double-blind, placebo-controlled experiment to examine the acute effects of a single dose of CoQ10 on the autonomic nervous system (ANS) by using power spectral analysis of HRV and energy metabolism at rest and during low intensity exercise in healthy subjects. Eleven nonsmoking healthy male students (age: 26+/-1 y) volunteered to participate in this experiment. CM5 lead ECG and gas exchange parameters were recorded 5 min before, and 30 min and 60 min after the oral administration of CoQ10 or a placebo. Following this, the subjects exercised using a stationary cycle ergometer for 10 min at 60 rpm with an intensity of 30% of heart rate reserve. During the exercise, the ECG and gas exchange parameters were recorded continuously. Results: There were no significant differences in heart rate between the CoQ10 and placebo trials at rest or during exercise. With regard to the integrated values of the spectrum, there were no significant differences in the HF power representing parasympathetic activity or LF power representing both sympathetic and parasympathetic nervous activities between the trials at any timepoint. However, during the exercise, HF power and LF power in the CoQ10 trial showed a tendency to increase compared with the placebo trial (p<0.1). Total power representing the over-all ANS activity was significantly increased in the CoQ10 trial during exercise, which implied that autonomic nervous activity was augmented by CoQ10 (p<0.05). CoQ10 also induced enhanced lipid oxidation as shown by the significantly lower respiratory gas exchange ratio (R) and increased fat oxidation during exercise. The results shed some light upon the relationship between the autonomic nervous activity and energy metabolism. Conclusion: These results suggested that CoQ10 may increase fat oxidation with augmented autonomic nervous activity during low intensity exercise.     

Effect of the combination of ginseng, oriental bezoar and glycyrrhiza on autonomic nervous activity as evaluated by power spectral analysis of HRV and cardiac depolarization-repolarization process

BACKGROUND: Ginseng, oriental bezoar and glycyrrhiza are the most widespread herbs often used in Kampo. These three herbs have been used for a Kampo for a thousand years and a number of pharmacological and clinical studies have reported about their effects. However, it has not been previously described how the combination of these most commonly used herbs affects the autonomic nervous system (ANS). OBJECTIVE: This is a randomized, double-blind, placebo-controlled experiment to examine the acute effects of Kampo on autonomic nervous activity by using power spectral analysis of heart rate variability (HRV) and cardiac depolarization-repolarization time intervals in humans. DESIGN: Ten healthy men volunteered to participate in this study. The Kampo at a dose of two capsules contained the following ingredients: powdered ginseng 250 mg, powdered oriental bezoar 50 mg, and powdered glycyrrhiza 50 mg. The placebo capsules contained corn starch. A CM5 lead ECG was recorded before, and 30 min and 60 min after the oral administration of Kampo or a placebo on different days. RESULTS: HF power (high frequency component in the HRV) was significantly increased and HR (heart rate) was significantly decreased after taking Kampo at 60 min (p<0.05) compared with the placebo. TP (total power) and LF power (low frequency component in the HRV) did not change significantly between the Kampo and placebo, and there were also no statistically significant differences in heart-rate-corrected ECG QT interval (QTc) or recovery time (RTc) between the Kampo and placebo. However, we observed that there was a tendency of decreased QTc interval and RTc after taking Kampo at 60 min compared with response of the placebo (p<0.1). CONCLUSIONS: These results indicated that the Kampo mainly potentiated parasympathetic nervous activity and may be useful for cardiovascular health.     

心内神经对蟾蜍心率变异的调节及其作用机制的研究

目的通过监测蟾蜍的心电图,比较动物清醒安静状态、离体灌流时HRV的不同,分析自主神经和体液因素对HRV的影响,观察心内神经对HRV的调节并分析其作用机制。方法选健康雄性中华蟾蜍50只,随机分为5组,在体组;离体组,阿托品(atropine,Atr)组;酚妥拉明(phentolamine,Phe)+β受体阻断剂普蔡洛尔(propranolol,Pro)组;Atr+Phe+Pro组,观察比较各相关指标。结果心脏离体后,与在体情况下相比,HR显著升高。正常心动周期的标准差(SDNN)显著降低,相邻正常心动周期差值的均方根(rMSSD)降低。离体给药组HRV各指标的比较,单独给予Atr后,HRV时域指标变化不明显,频域指标中HF变化不明显,LF、LF/HF显著增加;给予Phe+Pro后,HR显著降低,SDNN和rMSSD升高,LF、LF/HF降低;同时给予Atr+Phe+Pro后,HR变化无统计学意义,SDNN和rMSSD降低,HF降低,LF、LF/HF升高。结论离体状态下,心内神经对蟾蜍的HR和HRV有重要的调节作用,且以心内交感神经调节为主。     

哮喘患儿心率变异性的临床分析

目的将支气管哮喘患儿和正常儿童的心率变异性(HRV)进行对比分析,从而了解哮喘患儿自主神经功能的变化。方法应用24h动态心电图分别对35例哮喘患儿(其中哮喘急性发作期患儿20例,非发作期患儿15例)及健康正常儿童40例(对照)进行检查,并对两组儿童的HRV进行时域和频域分析。结果HRV中反映迷走神经张力指标的高频(HF)、正常相邻R-R间期差值的均方根(rMSSD)和一定时间内相邻R-R间期差值>50ms的次数占所有心动周期次数的百分比(pNN50)在哮喘组明显高于对照组(P<0.01),而反映交感神经张力的主要指标低频(LF)、24h正常R-R间期的标准差(SDNN)和24h每5min节段平均正常R-R间期标准差(SDANN)则明显低于对照组,且此变化在哮喘发作期更为明显。结论哮喘患儿的自主神经功能无论是在哮喘发作期还是非发作期均受到损害。     

The effect of dietary starch level on postprandial glucose and insulin concentrations in cats and dogs

A charge made against feeding dry foods to cats is that the high carbohydrate (i.e. starch) content results in high blood glucose levels which over time may have detrimental health effects. The present study determined the post-meal concentrations of plasma glucose and insulin in adult cats (seven males and four females) and dogs (Labrador retrievers; four males and five females) fed dry diets with low-starch (LS), moderate-starch (MS) or high-starch (HS) levels. In a cross-over design with at least 7 d between the test meals, plasma glucose and insulin concentrations were measured following a single meal of a LS, MS and HS diet (209 kJ/kg bodyweight). Only the HS diet resulted in significant post-meal increases in plasma glucose concentration in cats and dogs although the time-course profiles were different between the species. In cats, plasma glucose concentration was significantly increased above the pre-meal concentration from 11 h until 19 h after the meal, while in dogs, a significant increase above baseline was seen only at the 7 h time point. Plasma insulin was significantly elevated in dogs 4-8 h following the MS diet and 2-8 h after the HS diet. In cats, plasma insulin was significantly greater than baseline from 3-7 and 11-17 h after the HS diet. The time lag (approximately 11 h) between eating the HS diet and the subsequent prolonged elevation of plasma glucose concentration seen in cats may reflect metabolic adaptations that result in a slower digestive and absorptive capacity for complex carbohydrate.     

Body mass index is related to autonomic nervous system activity as measured by heart rate variability — A replication using short term measurements

Objectives

The present analysis is a replication of previous findings presenting first evidence of an association between body mass index (BMI) and autonomic nervous system (ANS) activity as measured by heart rate variability (HRV), in healthy non-obese adults.

Design

A total of fifty-nine apparently healthy male (M) and female (F) individuals (M/F = 15/44) were included in the trial. HRV data for analysis was derived from 5 minutes of baseline recordings, while the subject was sitting on a comfortable chair. Subjects’ body measures (weight and height) were taken and BMI was obtained according to common calculation (kg/m²).

Results

BMI was inversely related to pNN50 and RMSSD components of HRV. Statistically significant differences between stratified groups (BMI<20, BMI 20–25, BMI >25) only occurred for analysis of pNN50 components. The pNN50 components and RMSSD are strongly associated with cardiac vagal influence, and thus represents parasympathetic activity.

Conclusions

The present data supports previous findings, that sympatho-vagal balance is related to BMI in non-obese, healthy individuals, providing evidence for a prominent role of the vagus nerve in the modulation of the energy expenditure of the human organism. Furthermore, this relation can be observed in short term recordings of HRV of 5 minutes in length.     

Effects of capsaicin-containing yellow curry sauce on sympathetic nervous system activity and diet-induced thermogenesis in lean and obese young women

The present study was designed to investigate the effect of capsaicin, a pungent component of red pepper, on the sympathetic nervous system (SNS) activity and energy metabolism in 16 age- and height-matched lean and obese young women. The sympatho-vagal activities were assessed by means of spectral analysis of heart rate variability (HRV) during the resting condition and after the meal (2,016 kJ) with capsaicin (3 mg). Energy expenditure was also measured under the two conditions. There was no significant difference in any of the parameters of the HRV between the obese and control groups at rest. After the capsaicin diet, however, the very low frequency component (0.007-0.035 Hz) associated with thermogenesis (315.8+/-78.0 vs. 814.8+/-211.7 ms2 x Hz(-1), p<0.05) as well as its responsiveness (delta changes: 14.6+/-104.4 vs. 369.2+/-121.7 ms2 x Hz(-1), p<0.05) were significantly lower in the obese than the control group. Energy expenditure was significantly increased in the control group after the meal (5,574.7+/-221.2 to 6,114.7+/-239.0 kJ day(-1); p<0.01), but no such significant thermogenic response was detected in the obese group despite nearly identical lean body mass of the control group. Our data indicate that regardless of the resting level of sympatho-vagal activities, the reduced sympathetic responsiveness to physiological perturbation such as a capsaicin diet, which may cause impaired diet-induced thermogenesis and further weight gain, could be an important etiological factor leading to obesity in young women.     

Elevated plasma fatty acid concentrations stimulate the cardiac autonomic nervous system in healthy subjects

BACKGROUND: Fatty acids have been shown to stimulate the sympathetic nervous system in rats. Power spectral analysis of heart rate variability (HRV) is a safe and useful tool with which to evaluate cardiac autonomic nervous system (ANS) activity. Whether changes in plasma fatty acid concentrations affect the sympathetic nervous system or HRV in humans is unknown. OBJECTIVE: We investigated the possible changes in HRV after a significant increase in plasma fatty acid concentration. DESIGN: Subjects were randomly assigned to receive an infusion of lipid emulsion (10% triacylglycerol emulsion for 180 min) + heparin (a bolus of 200 U followed by 0.2 U*min(-)(1)*kg body wt(-)(1); n = 20) or 0.9% NaCl (for 180 min; n = 10). RESULTS: Lipid emulsion + heparin infusion was associated with a rise in plasma epinephrine and norepinephrine concentrations. The rise in plasma fatty acid concentration was associated with a significant decline in the RR interval (P: < 0.03) and in total power (P: < 0.03). Analysis of the different components of HRV showed that lipid emulsion + heparin infusion stimulated low- frequency (LF) components (P: < 0.03 at the second hour and P: < 0. 01 at the third hour) and inhibited high-frequency (HF) components (P: < 0.03 at the second and third hours). Consequently, the LF-HF ratio was significantly stimulated (P: < 0.03 at the second hour and P: < 0.01 at the third hour). Such results persisted, although attenuated, when the study was repeated in association with a propranolol infusion (n = 8). CONCLUSION: Elevated plasma fatty acid concentrations may stimulate cardiac autonomic nervous system activity.     

Response of cardiac autonomic modulation after a single exposure to musical auditory stimulation

The acute effects after exposure to different styles of music on cardiac autonomic modulation assessed through heart rate variability (HRV) analysis have not yet been well elucidated. We aimed to investigate the recovery response of cardiac autonomic modulation in women after exposure to musical auditory stimulation of different styles. The study was conducted on 30 healthy women aged between 18 years and 30 years. We did not include subjects having previous experience with musical instruments and those who had an affinity for music styles. The volunteers remained at rest for 10 min and were exposed to classical baroque (64-84 dB) and heavy metal (75-84 dB) music for 10 min, and their HRV was evaluated for 30 min after music cessation. We analyzed the following HRV indices: Standard deviation of normal-to-normal (SDNN) intervals, root mean square of successive differences (RMSSD), percentage of normal-to-normal 50 (pNN50), low frequency (LF), high frequency (HF), and LF/HF ratio. SDNN, LF in absolute units (ms²) and normalized (nu), and LF/HF ratio increased while HF index (nu) decreased after exposure to classical baroque music. Regarding the heavy metal music style, it was observed that there were increases in SDNN, RMSSD, pNN50, and LF (ms²) after the musical stimulation. In conclusion, the recovery response of cardiac autonomic modulation after exposure to auditory stimulation with music featured an increased global activity of both systems for the two musical styles, with a cardiac sympathetic modulation for classical baroque music and a cardiac vagal tone for the heavy metal style.     

Rats in acute withdrawal from ethanol exhibit left ventricular systolic dysfunction and cardiac sympathovagal balance shift

There is strong evidence that sympathovagal balance plays an important role in the progression of cardiac dysfunction in non-alcoholics. The purpose of this investigation was to determine whether a pattern of continuous ethanol intake and withdrawal modulates the cardiac sympathovagal balance and left ventricular (LV) systolic function in rats. Male Wistar rats were treated with a continuous ethanol liquid diet for 49 days, and then subjected to 1-day withdrawal and 21-day abstinence. Cardiac sympathovagal balance and LV systolic function were evaluated based on heart rate variability (HRV), Western blotting, and echocardiography. Longitudinal data obtained from the same rats showed that the 49-day continuous ethanol treatment induced LV systolic dysfunction, expressed by decreased fractional shortening and ejection fraction. At the 1-day withdrawal, LV systolic dysfunction was deteriorated, and the low-frequency power/high-frequency power (LF/HF) ratio in HRV was elevated because of the depressed HF and the increased LF. Western blot analysis showed an increased expression of myocardial tyrosine hydroxylase and a decreased expression of myocardial acetylcholine. All anomalies were recovered to baseline values with 21-day abstinence. We concluded that acute withdrawal from a 49-day continuous ethanol regimen is sufficient to promote the shift of cardiac sympathovagal balance toward sympathetic predominance and reduced vagal tone, contributing to the further deterioration of LV systolic function in rats. Those providing medical care for alcoholics should be aware of this enhanced susceptibility to LV systolic dysfunction with abrupt termination of a continuous ethanol regimen.     

Effect of palm oil on blood pressure, endothelial function and oxidative stress

The pathogenesis of hypertension has been associated with endothelial dysfunction and oxidative stress. We have previously shown that palm oil (PO), with an unsaturated-to-saturated fatty acid ratio close to one and rich in antioxidants vitamins, reduces oxidative stress-induced hypertension in normal rats. Here, we investigated the cardiovascular effects of natural vitamin-rich PO using the Dahl Salt-sensitive hypertension model. Male rats were fed either a high salt (8%NaCl, HS) or low salt (0.3% NaCl, LS) diet with or without PO (Carotino, 5 g/kg daily) for four weeks. Mean arterial pressure (MAP), heart rate, blood flow and vascular resistance, vascular reactivity in vitro as well as remodelling of second-order mesenteric arteries were measured. Plasma levels of nitric oxide (NO), prostacyclin, thromboxane A(2) (TXA(2)) and isoprostane (ISO), were determined by enzyme immunoassay. Plasma, heart and kidney GSH and GSSG levels were analyzed by HPLC and aortic superoxide ((.)O(2)-) production by fluorescence spectrometry. High salt induced an elevation in MAP that was associated with decreased NO, prostacyclin and GSH: GSSG ratio. Plasma ISO and TXA(2), aortic and renal vascular resistance as well as aortic (.)O(2)- were increased. Palm oil reduced MAP, plasma TXA(2) and vascular resistance of the renal and aortic arteries, and increased the GSH: GSSG ratio and NO in the LS group. The HS-induced elevation in ISO and (.)O(2)- production and the reductions in kidney GSH: GSSG ratio, were attenuated by PO. The effect of PO was also associated with a reduced vessel wall-thickness: lumen diameter ratio and a greater relaxant effect of mesenteric arteries to acetylcholine, in the LS group. The mortality associated with HS was reduced by PO. Thus, palm oil attenuates the progression of salt-induced hypertension and mortality, via mechanisms involving modulation of endothelial function and reduction in oxidative stress.