Short-term red wine consumption promotes differential effects on plasma levels of high-density lipoprotein cholesterol, sympathetic activity, and endothelial function in hypercholesterolemic, hypertensive, and healthy subjects

Alcohol Consumption: A New Risk Factor for Arterial Stiffness?

The relationship between alcohol consumption and cardiovascular disease risk is complex. Low-to-moderate daily alcohol consumption (1–2 drinks/day) is associated with reduced risk, whereas greater amounts of alcohol consumption and a “binge” pattern of drinking are associated with increased cardiovascular risk and mortality. Arterial stiffness may help explain the complex relationship. This integrated review summarizes data from studies examining the associations between alcohol consumption and pulse wave velocity, a gold standard measure of arterial stiffness. We also briefly review the concept and methodology of pulse wave velocity measurement as well as the mechanisms of alcohol-induced arterial stiffening. Findings among the different studies reviewed were inconsistent with methodological challenges related to alcohol use assessment. While making specific conclusions regarding this relationship is tenuous; the data suggest that excessive alcohol consumption or a binge drinking pattern is associated with increased arterial stiffness.

Endothelium-Independent Relaxation of Vascular Smooth Muscle Induced by Persimmon-Derived Polyphenol Phytocomplex in Rats

The vasorelaxant effect of polyphenols is well known, and the mortality rate due to coronary artery disease is low in people who consume polyphenol-containing foods. We aimed to elucidate the mechanism by which polyphenols derived from persimmon juice (PJ) and persimmon leaves (PLs) induce vasorelaxation and suppress vasocontraction in the superior mesenteric arteries isolated from male Sprague Dawley rats. Vasocontraction was induced with 1 µM phenylephrine, and polyphenol-induced vasorelaxation was expressed as a percentage of the previous tone induced by phenylephrine. PJ powder (100 mg/L) induced higher levels of vasorelaxation (mean ± standard error of the mean, 88.6% ± 4.4%) than PLs powder (1 g/L; 72.0% ± 10.8%). Nitric oxide pathway inhibitors (NG-nitro-L-arginine methyl ester + carboxy-PTIO) did not affect persimmon-derived polyphenol-induced vasorelaxation, whereas potassium chloride, tetraethylammonium, and potassium-channel inhibitors did. Vasorelaxation was endothelium independent with both extracts. Phenylephrine-induced vasocontraction was suppressed by pretreatment with PJ and PLs powder, even when inositol triphosphate-mediated Ca²⁺ release and extracellular Ca²⁺ influx were inhibited. These results suggest that persimmon-derived polyphenol phytocomplex cause vasorelaxation and inhibit vasocontraction through hyperpolarization of smooth muscle cells. Persimmon-derived polyphenols may be able to prevent cardiovascular diseases caused by abnormal contraction of blood vessels.

From bench to bar side: Evaluating the red wine storage lesion

Vitally essential red fluids like packed cells and red wine are seriously influenced in quality when stored over prolonged periods. In the case of red cell concentrates, the resulting storage lesion has particular significance in perioperative medicine. We hypothesized that, in contrast, aging rather improves the properties of red wine in several ways. A translational approach, including (I) in vitro experiments, (II) a randomized, blinded crossover trial of acute clinical effects, and (III) a standardized red wine blind tasting was used. Three monovarietal wines (Cabernet Sauvignon, Chianti, Shiraz) in three different vintages (range 2004-2016), each 5 years different, were assessed. Assessments were performed at a German university hospital (I, II) and on a garden terrace during a mild summer evening (III). Young wines induced cell stress and damage while significantly reducing cytoprotective proteins in HepG2 hepatoma cells. Sympathetic activity and multitasking skills were altered depending on wines' ages. Hangovers tended to be aggravated by young red wine. Aged variants performed better in terms of aroma and overall quality but worse in optical appearance. We found no evidence for a red wine storage lesion. However, we plead for consensus-based guidelines for proper storage, as it is common in clinical medicine.

The effects of alcohol consumption on flow-mediated dilation in humans: A systematic review

Changes in endothelial function may contribute to the positive and negative effects of alcohol consumption on cardiovascular conditions, such as hypertension and coronary artery disease. Numerous studies have used brachial artery flow-mediated dilation (FMD) to examine the effects of alcohol consumption on endothelial function in humans. However, the findings are inconsistent and may be due to multiple factors such as heterogeneity in subject characteristics, the alcohol use pattern, and amount/dose of alcohol consumed. Therefore, the aim of this systematic review was to investigate the effect of alcohol consumption on brachial artery FMD in humans considering the above-mentioned factors. This review found that while light to moderate alcohol consumption may have minimal effects on FMD, heavy alcohol consumption was associated with a decrease in FMD. However, most of the published studies included healthy, younger, and male individuals, limiting generalizability to other populations. Future studies should include more women, older subjects, and those from diverse and underrepresented backgrounds.

Morning sympathetic activity after evening binge alcohol consumption

Binge alcohol consumption elicits acute and robust increases of muscle sympathetic nerve activity (MSNA), yet the impact of evening binge drinking on morning-after MSNA is unknown. The present study examined the effects of evening binge alcohol consumption on polysomnographic sleep and morning-after MSNA. We hypothesized that evening binge drinking (i.e. 4-5 drink equivalent in <2 h) would reduce sleep quality and increase morning-after blood pressure (BP) and MSNA. Following a familiarization night within the sleep laboratory, 22 participants (12 men, 10 women; 25 ± 1 yr) were examined after simulated binge drinking or fluid control (randomized, crossover design). Morning MSNA was successfully recorded across both conditions in 16 participants (8 men, 8 women) during a 10-min baseline and three Valsalva's maneuvers (VM). Binge drinking reduced rapid eye movement (REM) sleep (15 ± 1 vs. 20 ± 1%, P = 0.003), increased stage II sleep (54 ± 1 vs. 51 ± 1%, P = 0.002), and increased total urine output (2.9 ± 0.2 vs. 2.1 ± 0.1 liters, P < 0.001) but did not alter morning-after urine specific gravity. Binge drinking increased morning-after heart rate [65 (54-72) vs. 58 (51-67) beats/min, P = 0.013] but not resting BP or MSNA. Binge drinking elicited greater sympathoexcitation during VM (38 ± 3 vs. 43 ± 3 bursts/min, P = 0.036). Binge drinking augmented heart rate (P = 0.002), systolic BP (P = 0.022), and diastolic BP (P = 0.037) reactivity to VM phase IV and blunted cardiovagal baroreflex sensitivity during VM phases II (P = 0.028) and IV (P = 0.043). In conclusion, evening binge alcohol consumption disrupted REM sleep and morning-after autonomic function. These findings provide new mechanistic insight into the potential role of binge drinking on cardiovascular risk.NEW & NOTEWORTHY Chronic binge alcohol consumption is associated with future cardiovascular disease (CVD) risk in both men and women. In addition, binge alcohol consumption is known to disrupt normal sleep quality during the early morning hours, coinciding with the morning sympathetic surge. In the present study, an evening of binge alcohol consumption increased baseline morning heart rate and cardiovascular reactivity during the Valsalva maneuver (VM) strain. Specifically, muscle sympathetic nerve activity and phase IV hemodynamic responses increased during VM the morning after binge alcohol consumption. The autonomic dysfunction and increased cardiovascular reactivity during VM suggests a contributing mechanism to CVD risk present in individuals who binge drink.

Evaluation of the brachial artery endothelial function in chronic alcohol consumption among males by high-frequency ultrasonography

OBJECTIVE

There is evidence suggesting that different volumes of chronic alcohol consumption have different effects on the endothelium. Therefore, using high-frequency ultrasonography, we evaluate the effects of the different volume and duration of alcohol intake on brachial artery endothelial function in chronic drinkers.

METHODS

Ninety-two male chronic episodic alcoholics were grouped by alcohol intake amount and duration: mild (group B, n=30); ≤90 mg ethanol daily, 3-5 days/wk for 5-8 years; moderate (group C, n=30); 90-150 mg ethanol daily, 3-5 days/wk for 9-20 years; and severe (group D, n=32); ≥150 mg ethanol daily, 6-7 days/wk for more than 10 years. Thirty male nondrinkers were recruited as the control group A. High-frequency ultrasonography was used to measure brachial artery diameter during rest, during reactive hyperemia and following the administration of nitroglycerin. Endothelial-dependent brachial artery flow-mediated dilatation (FMD) and endothelial-independent brachial artery nitrate-mediated dilatation (NMD) were calculated.

RESULTS

Flow-mediated dilatation values for group C and D were significantly lower than those for group A and B (V_C =7.63±0.22, V_D =5.85±0.23 vs V_A =13.35±0.35, V_B =12.81±0.36, P<.01). The FMD of group D was significantly lower than that of group C (P<.01). Meanwhile, the NMD of group D was significantly lower than that of the other groups (V_D =17.33±6.21 vs V_A =25.35±7.42, V_B =24.52±8.30, V_C =23.35±7.27, P<.01).

CONCLUSIONS

Chronic moderate-to-heavy alcohol consumption caused endothelial dysfunction, even damaging vascular smooth muscle cells in cases of heavy alcohol consumption, while abstinence and chronic mild alcoholics caused no effect on endothelial function.

Molecular Properties of Red Wine Compounds and Cardiometabolic Benefits

Wine has been used since the dawn of human civilization. Despite many health benefits, there is still a lot of discussion about the real properties of its components and its actions on cells and molecular interactions. A large part of these issues permeate the fine line between the amount of alcohol that causes problems to organic systems and the amount that could be beneficial for the health. However, even after the process of fermentation, wine conserves different organic compounds from grapes, such as polysaccharides, acids, and phenolic compounds, such as flavonoids and nonflavonoids. These substances have known anti-inflammatory and antioxidant capacities, and are considered as regulatory agents in cardiometabolic process. In this study, the main chemical components present in the wine, its interaction with molecules and biological mechanisms, and their interference with intra- and extracellular signaling are reviewed. Finally, the properties of wine that may benefit cardiovascular system are also revised.

Effect of Grape Polyphenols on Blood Pressure: A Meta-Analysis of Randomized Controlled Trials

Background

The effect of grape polyphenols on blood pressure remains unclear, which we aimed to address via a meta-analysis study.

Methods

We conducted study trial searches in PubMed, Embase, and the Cochrane Library databases. Summary estimates of weighted mean differences and 95% confidence intervals were obtained by using fixed-effects models. Subgroup analyses were performed to identify the source of heterogeneity. The protocol details of our meta-analysis have been submitted to the international database of prospectively registered systematic reviews (registration number CRD42015019196).

Results

Ten studies were included in the present meta-analysis. Our results showed daily grape polyphenol intake could significantly reduce systolic blood pressure by 1.48 mmHg when compared to control subjects (12 comparisons; -1.48 [-2.79 to -0.16] mmHg; P = 0.03). Subgroup analyses indicated larger reduction was identified in the intake of low-dose of grape polyphenols (< 733 mg/day, median level of the included studies) or patients with metabolic syndrome. Contrarily, diastolic blood pressure was not significantly decreased in the grape polyphenols group as compared to controls. No significant heterogeneity or publication bias was detected in the meta-analysis of either systolic or diastolic blood pressure.

Conclusions

Daily grape polyphenol intake can significantly reduce the systolic blood pressure in humans, although the reduction is modest when compared with anti-hypertensive medications. Larger, better designed trials, that specifically include hypertensive subjects, are required to verify our results in the future.

Endothelium and its alterations in cardiovascular diseases: life style intervention

The endothelium, which forms the inner cellular lining of blood vessels and lymphatics, is a highly metabolically active organ that is involved in many physiopathological processes, including the control of vasomotor tone, barrier function, leukocyte adhesion, and trafficking and inflammation. In this review, we summarized and described the following: (i) endothelial cell function in physiological conditions and (ii) endothelial cell activation and dysfunction in the main cardiovascular diseases (such as atherosclerosis, and hypertension) and to diabetes, cigarette smoking, and aging physiological process. Finally, we presented the currently available evidence that supports the beneficial effects of physical activity and various dietary compounds on endothelial functions.

Effects of dark chocolate and cocoa consumption on endothelial function and arterial stiffness in overweight adults

The consumption of cocoa and dark chocolate is associated with a lower risk of CVD, and improvements in endothelial function may mediate this relationship. Less is known about the effects of cocoa/chocolate on the augmentation index (AI), a measure of vascular stiffness and vascular tone in the peripheral arterioles. We enrolled thirty middle-aged, overweight adults in a randomised, placebo-controlled, 4-week, cross-over study. During the active treatment (cocoa) period, the participants consumed 37 g/d of dark chocolate and a sugar-free cocoa beverage (total cocoa = 22 g/d, total flavanols (TF) = 814 mg/d). Colour-matched controls included a low-flavanol chocolate bar and a cocoa-free beverage with no added sugar (TF = 3 mg/d). Treatments were matched for total fat, saturated fat, carbohydrates and protein. The cocoa treatment significantly increased the basal diameter and peak diameter of the brachial artery by 6% (+2 mm) and basal blood flow volume by 22%. Substantial decreases in the AI, a measure of arterial stiffness, were observed in only women. Flow-mediated dilation and the reactive hyperaemia index remained unchanged. The consumption of cocoa had no effect on fasting blood measures, while the control treatment increased fasting insulin concentration and insulin resistance (P= 0·01). Fasting blood pressure (BP) remained unchanged, although the acute consumption of cocoa increased resting BP by 4 mmHg. In summary, the high-flavanol cocoa and dark chocolate treatment was associated with enhanced vasodilation in both conduit and resistance arteries and was accompanied by significant reductions in arterial stiffness in women.

The acute effects of grape polyphenols supplementation on endothelial function in adults: meta-analyses of controlled trials

Background

The acute effects of grape polyphenols on endothelial function in adults are inconsistent. Here, we performed meta-analyses to determine these acute effects as measured by flow-mediated dilation (FMD).

Methods

Trials were searched in PubMed, Embase and the Cochrane Library database. Summary estimates of weighted mean differences (WMDs) and 95% CIs were obtained by using random-effects models. Meta-regression and subgroup analyses were performed to identify the source of heterogeneity. The protocol details of our meta-analysis have been submitted to the PROSPERO register and our registration number is CRD42013004157.

Results

Nine studies were included in the present meta-analyses. The results showed that the FMD level was significantly increased in the initial 120 min after intake of grape polyphenols as compared with controls. Meta-regression and subgroup analyses were performed and showed that a health status was the main effect modifier of the significant heterogeneity. Subgroups indicated that intake of grape polyphenols could significantly increase FMD in healthy subjects, and the increased FMD appeared to be more obviously in subjects with high cardiovascular risk factors. Moreover, the peak effect of grape polyphenols on FMD in healthy subjects was found 30 min after ingestion, which was different from the effect in subjects with high cardiovascular risk factors, in whom the peak effect was found 60 min after ingestion.

Conclusions

Endothelial function can be significantly improved in healthy adults in the initial 2 h after intake of grape polyphenols. The acute effect of grape polyphenols on endothelial function may be more significant but the peak effect is delayed in subjects with a smoking history or coronary heart disease as compared with the healthy subjects.

Short-term administration of alibernet red wine extract failed to affect blood pressure and to improve endothelial function in young normotensive and spontaneously hypertensive rats

As wine polyphenols were shown to possess many positive effects in mammals, including improvement of vascular function, this study investigated the effect of the Slovak Alibernet red wine extract (AWE) on blood pressure and vascular function in young normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats. Six weeks old, male, WKY and SHR were treated with AWE for three weeks at the dose of 24.2 mg/kg/day. Blood pressure (BP), determined by tail-cuff plethysmography, was significantly elevated in SHR vs. WKY and AWE failed to affect it. Lipid peroxidation was evaluated by determination of thiobarbituric acid-reactive substances. Vascular function was assessed in rings of the femoral artery using Mulvany-Halpern's myograph. Maximal endothelium-dependent acetylcholine (ACh)-induced relaxation was reduced in control SHR vs. WKY rats by approximately 9.3 %, which was associated with a significant decrease of its NO-independent component. AWE failed to affect maximal ACh-induced relaxation, both its NO-dependent and independent components, compared to controls of the same genotype. AWE however reduced lipid peroxidation in the left ventricle of both WKY and SHR and in the liver of SHR. In conclusion, three-week administration of AWE failed to reduce BP and to improve endothelial function in the femoral arteries of both genotypes investigated.

Dietary flavan-3-ols intake and metabolic syndrome risk in Korean adults

Flavan-3-ols are a subclass of flavonoids found in a variety of foods including teas. The effects of flavan-3-ols on the risk of metabolic syndrome (MetS) have been investigated, generally focusing on tea catechins or individual flavan-3-ol rich foods, but there is little information on dietary flavan-3-ols intake and risk of MetS in population-based studies. In this cross-sectional study, we examined the association between dietary flavan-3-ols intake and the risk of MetS in Korean adults. Subjects comprised 1,827 men and 2,918 women aged 20-69 years whose data was included in the 2008 Korean National Health and Nutrition Examination Survey. This survey was conducted between January 2008 and December 2008. Total flavan-3-ols intakes were calculated from 24-hour dietary recalls using a flavonoids database. Thirty percent of the male subjects and 24% of the female subjects were reported as having MetS. In the female subjects, flavan3-ols intake was inversely associated with the risk of MetS after adjusting for potential confounders (5th vs. 1st quintile, OR = 0.64, 95% CI = 0.45-0.91, P for trend = 0.384). The main food source of flavan-3-ols was green tea followed by apples and grapes. Among MetS components, flavan3-ols intake was inversely associated with the risk of high blood pressure after adjusting for potential confounders (5th vs. 1st quintile, OR = 0.64, 95% CI = 0.45-0.90, P for trend = 0.005). No significant association between flavan-3-ols intake and risk of MetS was found in the male subjects. After stratified analysis by obesity (BMI ≥ 25 or BMI < 25), however, flavan3-ols intake was inversely related to the risk of hypertension in non-obese men. These results suggest that dietary flavan-3-ols intake may have beneficial effects on MetS risk by reducing the risk of hypertension. The effects of flavan-3-ols intake dependent on obesity need further investigation.

Red wine: A drink to your heart

Mortality and morbidity are still high in cardiovascular disease (CVD). Myocardial ischemia reperfusion injury leading to myocardial infarction is one of the most frequent causes of the death in humans. Atherosclerosis and generation of reactive oxygen species through oxidative stress is the major risk factor for CVD. From the literature collection, it has been identified that moderate consumption of red wine helps in preventing CVD through several mechanisms, including increasing the high-density lipoprotein cholesterol plasma levels, decreasing platelet aggregation, by antioxidant effects, and by restoration of endothelial function. The aim of this review is to discuss the accumulating evidence that suggests that red wine possesses a diverse range of biological actions and may be beneficial in the prevention of CVD.

The relationship between body mass index and the variation in plasma levels of triglycerides after short-term red wine consumption

BACKGROUND

Alcoholic beverages may have protective cardiovascular effects but are known to increase the plasma levels of triglycerides (TG). Both TG and the ratio of TG to high-density lipoprotein cholesterol (TG/HDL-cholesterol) are associated with increased cardiovascular risk.

OBJECTIVES

To determine the predictive factors for variations in plasma levels of TG and the TG/HDL-cholesterol ratio in patients after they had consumed red wine for 14 days.

METHODS

Forty-two subjects (64% men, 46 ± 9 years, baseline body mass index [BMI] 25.13 ± 2.76 kg/m(2)) were given red wine (12% or 12.2% alc/vol, 250 mL/day with meals). Plasma concentration of lipids and glucose were measured before and after red wine consumption. Blood was collected after 12 hours of fast and alcohol abstention.

RESULTS

Red wine increased plasma levels of TG from 105 ± 42 mg/dL to 120 ± 56 mg/dL (P = .001) and the TG/HDL-cholesterol ratio from 2.16 ± 1.10 to 2.50 ± 1.66 (P = .014). In a multivariate linear regression model that included age, baseline BMI, blood pressure, lipids, and glucose, only BMI was independently predictive of the variation in plasma TG after red wine (beta coefficient 0.592, P < .001). BMI also predicted the variation in TG/HDL-cholesterol ratio (beta coefficient 0.505, P = .001, adjusted model). When individuals were divided into three categories, according to their BMI, the average percentage variation in TG after red wine was -4%, 17%, and 33% in the lower (19.60-24.45 kg/m(2)), intermediate, and greater (26.30-30.44 kg/m(2)) tertiles, respectively (P = .001).

CONCLUSIONS

Individuals with higher BMI, although nonobese, might be at greater risk for elevation in plasma TG levels and the TG/HDL-cholesterol ratio after short-term red wine consumption.

The characteristics of stress cardiomyopathy in an ethnically heterogeneous population

OBJECTIVES

Stress cardiomyopathy is a cardiac syndrome that is characterized by transient left ventricular systolic dysfunction in the absence of obstructive coronary artery disease. Its epidemiology has been described in homogeneous Asian, Caucasian and Black populations, but its characteristics in heterogeneous populations are poorly understood. Our aim was to assess the characteristics of stress cardiomyopathy in a heterogeneous population that included a large percentage of Hispanics.

METHODS

We reviewed 59 consecutive cases of stress cardiomyopathy that were confirmed by coronary angiography and were in agreement with the Mayo Clinic diagnostic criteria.

RESULTS

The mean age of the patients was 74 years (range, 39-91 years), and 37 patients were female (62.7%). Twenty-nine patients (49.2%) were Latino/Hispanic, 26 (44%) were Caucasian, 3 (5%) were Asian, and 1 patient (1.7%) was Black. The most common chief symptom was dyspnea, followed by chest pain and an absence of symptoms in 54.2, 28.8, and 18.6% of the patients, respectively. The primary EKG abnormalities consisted of a T wave inversion, an ST segment elevation, and ST segment depression in 69.5%, 25.4%, and 15.3% of the patients, respectively. The stressor event was identified in 90% of the cases. In 32 cases (54%), the stressor event was physical stress or a medical illness, and in 21 cases (35.6%), the stressor event was emotional stress. The in-hospital mortality rate was 8.5%.

CONCLUSIONS

In our heterogeneous study population, stress cardiomyopathy presented with a 3:2 female-to-male ratio, and dyspnea was the most common chief complaint. Stress cardiomyopathy exhibited a T wave inversion as the primary EKG abnormality. These findings differ from previous cases that have been reported, and further studies are needed.

Polyphenols and human health: prevention of disease and mechanisms of action

Polyphenols are found ubiquitously in plants and their regular consumption has been associated with a reduced risk of a number of chronic diseases, including cancer, cardiovascular disease (CVD) and neurodegenerative disorders. Rather than exerting direct antioxidant effects, the mechanisms by which polyphenols express these beneficial properties appear to involve their interaction with cellular signaling pathways and related machinery that mediate cell function under both normal and pathological conditions. We illustrate that their interactions with two such pathways, the MAP kinase (ERK, JNK, p38) and PI3 kinase/Akt signaling cascades, allow them to impact upon normal and abnormal cell function, thus influencing the cellular processes involved in the initiation and progression of cancer, CVD and neurodegeneration. For example, their ability to activate ERK in neurons leads to a promotion of neuronal survival and cognitive enhancements, both of which influence the progression of Alzheimer’s disease, whilst ERK activation by polyphenols in vascular endothelial cells influences nitric oxide production, blood pressure and ultimately CVD risk. The main focus of this review is to provide an overview of the role that polyphenols play in the prevention of cancer, cardiovascular disease and neurodegeneration. We present epidemiological data, human intervention study findings, as well as animal and in vitro studies in support of these actions and in each case we consider how their actions at the cellular level may underpin their physiological effects.

Polyphenol-induced endothelium-dependent relaxations role of NO and EDHF

The Mediterranean diet has been associated with greater longevity and quality of life in epidemiological studies. Indeed, because of the abundance of fruits and vegetables and a moderate consumption of wine, the Mediterranean diet provides high amounts of polyphenols thought to be essential bioactive compounds that might provide health benefits in terms of cardiovascular diseases and mortality. Several polyphenol-rich sources, such as grape-derived products, cocoa, and tea, have been shown to decrease mean blood pressure in patients with hypertension. The improvement of the endothelial function is likely to be one of the mechanisms by which polyphenols may confer cardiovascular protection. Indeed, polyphenols are able to induce nitric oxide (NO)-mediated endothelium-dependent relaxations in a large number of arteries including the coronary artery; they can also induce endothelium-derived hyperpolarizing factor (EDHF)-mediated relaxations in some of these arteries. Altogether, these mechanisms might contribute to explain the antihypertensive and cardio-protective effects of polyphenols in vivo. The aim of this review was to provide a nonexhaustive analysis of the effect of several polyphenol-rich sources and isolated compounds on the endothelium in in vitro, ex vivo, and in vivo models as well as in humans.

ATZ (3-amino-1,2,4-triazole) injected into the fourth cerebral ventricle influences the Bezold-Jarisch reflex in conscious rats

OBJECTIVES

Many studies have investigated the importance of oxidative stress on the cardiovascular system. In this study we evaluated the effects of central catalase inhibition on cardiopulmonary reflex in conscious Wistar rats.

METHODS

Male Wistar rats were implanted with a stainless steel guide cannula in the fourth cerebral ventricle. The femoral artery and vein were cannulated for mean arterial pressure and heart rate measurement and for drug infusion, respectively. After basal mean arterial pressure and heart rate recordings, the cardiopulmonary reflex was tested with a dose of phenylbiguanide (PBG, 8 μg/kg, bolus). Cardiopulmonary reflex was evaluated before and μ l15 minutes after 1.0 μl 3-amino-1,2,4-triazole (ATZ, 0.01 g/100 μl)0.01 g/100 μl) injection into the fourth cerebral ventricle. Vehicle treatment did not change cardiopulmonary reflex responses.

RESULTS

Central ATZ significantly increased hypotensive responses without influencing the bradycardic reflex.

CONCLUSION

ATZ injected into the fourth cerebral ventricle increases sympathetic inhibition but does not change the parasympathetic component of the cardiopulmonary reflex in conscious Wistar rats.