Nonpharmacologic therapies that reduce blood pressure: a fresh perspective

Comprehensive nutritional, anti-nutritional, ICP-MS and FTIR profiling of Ficus rumphii leaves: a potential source for dietary enhancement

Ficus rumphii is a plant belonging to the Moraceae family. This study aimed to profile the functional groups using FTIR, as well as nutritional, elements using ICP-MS technique, and anti-nutritional analyses of Ficus rumphii leaves. The results of nutritional analysis of Ficus rumphii leaves revealed that the leaves had a diverse proximate composition with derived nutritional value to be 314.11 ± 0.31 kcal/100g. The leaves demonstrated good levels of ash, crude fibre, carbohydrate, crude fat, moisture, crude protein and nutritive value. The anti-nutrients were present at proportions that are not dangerous. Furthermore, the ICP-MS analysis revealed that Ficus rumphii leaves were also abundant in essential elements. FTIR analysis identified several functional groups such as O-H, N-H, C-H, O = C = O, C = O, C = N, C = C, etc. Hence, the findings of this study indicate that the leaves of wild plant Ficus rumphii possess significant nutritional potential, making it an excellent plant for meeting dietary requirements.

Physicochemical Characteristics of Vinegar from Banana Peels and Commercial Vinegars before and after In Vitro Digestion

Vinegar is a fermented food with a diversity of uses seasoning, salad dressing and flavouring for foods. Since ancient times it is considered a remedy for health and today there are different types of vinegar on the market, and many others are under development. Determination of the physicochemical characteristics of the new types of vinegar is necessary in order to improve them. Therefore, the aim of this paper is to compare the physicochemical characteristics of vinegar obtained from banana peels (with or without boiling peels) at different ages, with those of commercial vinegars. The vinegar from banana peels was obtained and aged in our laboratory, while the commercial vinegars were purchased from a local market. The physicochemical characteristics of all the samples were investigated before and after gastric and intestinal digestion. Inductively coupled plasma mass spectrometry was used to determine the mineral content of the vinegars. Additionally, statistical analysis of the results was performed by applying a one-way analysis of variance. Results showed that vinegar obtained from banana peels is clearer and total dry extract values are lower than those of commercial vinegars. Banana peel vinegars have higher antioxidant activity and total polyphenol content similar to the commercial balsamic vinegars. This study advances the knowledge in the field of vinegar production by using raw agricultural by-products.

Blood Pressure Effects of Sodium Reduction: Dose-Response Meta-Analysis of Experimental Studies

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Background:

The relationship between dietary sodium intake and blood pressure (BP) has been tested in clinical trials and nonexperimental human studies, indicating a direct association. The exact shape of the dose–response relationship has been difficult to assess in clinical trials because of the lack of random-effects dose–response statistical models that can include 2-arm comparisons.

Methods:

After performing a comprehensive literature search for experimental studies that investigated the BP effects of changes in dietary sodium intake, we conducted a dose–response meta-analysis using the new 1-stage cubic spline mixed-effects model. We included trials with at least 4 weeks of follow-up; 24-hour urinary sodium excretion measurements; sodium manipulation through dietary change or supplementation, or both; and measurements of systolic and diastolic BP at the beginning and end of treatment.

Results:

We identified 85 eligible trials with sodium intake ranging from 0.4 to 7.6 g/d and follow-up from 4 weeks to 36 months. The trials were conducted in participants with hypertension (n=65), without hypertension (n=11), or a combination (n=9). Overall, the pooled data were compatible with an approximately linear relationship between achieved sodium intake and mean systolic as well as diastolic BP, with no indication of a flattening of the curve at either the lowest or highest levels of sodium exposure. Results were similar for participants with or without hypertension, but the former group showed a steeper decrease in BP after sodium reduction. Intervention duration (≥12 weeks versus 4 to 11 weeks), type of study design (parallel or crossover), use of antihypertensive medication, and participants’ sex had little influence on the BP effects of sodium reduction. Additional analyses based on the BP effect of difference in sodium exposure between study arms at the end of the trial confirmed the results on the basis of achieved sodium intake.

Conclusions:

In this dose–response analysis of sodium reduction in clinical trials, we identified an approximately linear relationship between sodium intake and reduction in both systolic and diastolic BP across the entire range of dietary sodium exposure. Although this occurred independently of baseline BP, the effect of sodium reduction on level of BP was more pronounced in participants with a higher BP level.

Nutritional Characteristics of Four Underutilized Edible Wild Fruits of Dietary Interest in Ghana

Malnutrition has been a serious issue in Ghana and Africa as a whole. However, the potential of many indigenous fruits to combat it has not yet been tested. Therefore, this study aimed to determine the nutritional characteristics of four underutilized wild fruits (Gardenia erubescens, Sclerocarya birrea, Diospyros mespiliformis, and Balanites aegyptiaca) of dietary interest in Ghana. The nutritional and antinutritional characteristics of the fruits were analyzed according to standard methods (laid down by the Association of Official Analytical Chemists and other well-known researchers) on a dry weight (dw) basis. The nutritional value of the fruits was high enough to contribute to the nutrient requirements of humans, with their iron (0.34⁻1.46 mg/100 g), zinc (0.81⁻2.97 mg/100 g), vitamin A (0.84⁻2.03 mg/100 g), and β-carotene (64.84⁻176.89 mg/100 g) contents worth special mention. The antinutrient content also ranged between 0.06⁻1.82 mg/g. Therefore, it is evident from the study that the fruits, although containing some levels of antinutrients, are nutrient-dense, suggesting their potency in fighting malnutrition in humans.

Use of physician-recommended non-pharmacological strategies for hypertension control among hypertensive patients

This study aims to evaluate the 4 non-pharmacological strategies adopted by patients for hypertension control and patient characteristics that affect the choice of strategies. Four thousand hypertensive patients aged ≥18 years were selected from the National Health and Nutrition Examination Survey. Odds ratios of the choice of strategies were analyzed using weighted logistic models. Clinical recommendations of non-pharmacological strategies for hypertension control were relatively low. More exercise was the least frequent strategy used for hypertension control. More patients reported using ≥3 strategies than using ≤2 strategies (79.1% vs 20.9%, P < .0001). Non-Hispanic blacks were more likely to use each individual strategy and to use ≥3 strategies simultaneously. Patients with obesity and diabetes were less likely to attempt weight control or more exercise, but more likely to use ≥3 strategies than peers. Educational programs should be developed to enhance physician's advice for lifestyle modifications and to increase patient's acceptance of physical activity.

Determination of vitamins, minerals, and microbial loads of fortified nonalcoholic beverage (kunun zaki) produced from millet

The objective of this study was to evaluate the possibility of fortifying kunun zaki with tigernut milk extract due to nutritional deficiency of the former. Kunun zaki and tigernut milk extract (TME) were produced using traditional methods, with little modification. They were mixed in respective percentages of 90:10 (KN10), 80:20 (KN20), and 70:30 (KN30) while whole kunun zaki without addition of tigernut milk extract (KN00) served as control. The resulting kunun zaki samples were analyzed for proximate composition, vitamins, minerals, microbial loads, and sensory evaluation. Results showed improvement in thiamine and riboflavin contents of the fortified samples over the unfortified counterparts, with the KN30 sample having highest values of 1.05 and 0.56 mg/kg thiamine and riboflavin, respectively. Minerals were higher in the samples containing TME than their KN00 counterparts; the KN30 sample had highest values of 23.5, 8.8, 148.9, 63.7, 6.7, and 18.6 mg/100 mL for respective Na, Ca, K, Mg, P, and Fe while lowest values were recorded for the KN00 sample. Microbial analysis indicated that total viable bacteria and yeast and molds were in the range 2.2–2.6 and 2.1–2.7 log CFU/g, respectively, while there was no detection of coliforms and Staphylococcus in the samples. The sensory evaluation of the kunun zaki samples indicated that higher mean scores were recorded for samples containing TME than those without it in most of the attributes tested. The KN30 sample was most preferred, having highest mean scores of 7.2, 7.8, 6.9, and 7.4 in the attributes of appearance, flavor, taste, and acceptability, respectively. The study concluded that inclusion of tigernut extract in kunun zaki resulted in improved nutritional and sensory qualities.

Dietary mineral intakes of rural midlife to older adult women with prehypertension in Midwestern United States

OBJECTIVES

Midlife to older rural women with prehypertension are at increased risk for hypertension and its impact on cardiovascular health with advancing age. Because modification of dietary factors could help alleviate risk, the objective of this study was to explore calcium, magnesium, potassium and sodium intakes of midlife to older rural women, with identification of their top food sources.

DESIGN

Survey of baseline dietary intake data of women and comparison to standard recommendations.

SETTING

Rural Midwestern United States.

PARTICIPANTS

289 rural women, age 40-69, with prehypertension who volunteered for lifestyle modification to reduce blood pressure.

MEASUREMENTS

Baseline nutrition data using the Block Health Habit and History Questionnaire were collected over a twelve-month rolling enrollment period from rural women with prehypertension. Mineral intakes were calculated and compared to recommended standards. Top ten foods contributing to each mineral were identified.

RESULTS

The percent of women who met the Recommended Dietary Allowance (RDA)/Adequate Intake (AI) recommendations for their age groups ranged from a high 42.9% for magnesium to a low of 4.2% for potassium. Mean intakes of calcium, magnesium and potassium were all below recommended levels and sodium intakes were above recommendation.

CONCLUSION

Midlife to older rural US women with prehypertension were eating some of the foods that would help them meet mineral recommendations. As a preventive approach to reducing hypertension risk, clinical practice could include advising on ways to increase both commonly and less commonly consumed nutrient-rich foods with awareness of what is typically available in the rural area.

Efeitos de um programa de exercicios fisicos sobre a pressao arterial e medidas antropometricas

INTRODUÇÃO: O número de pessoas com sobrepeso ou obesidade tem alcançado índices alarmantes no Brasil. Condutas não-medicamentosas devem ser a estratégia inicial para o tratamento de indivíduos com sobrepeso e hipertensão leve a moderada. OBJETIVO: Analisar os efeitos de um programa de condicionamento físico realizado por um período de 24 meses sobre pressão arterial e composição corporal em indivíduos normotensos e pré-hipertensos. MÉTODOS: Participaram do estudo 35 indivíduos randomizados como: (GI) normotensos (n = 16), 51 ± 1 anos, pressão arterial sistólica (PAS) < 120 e diastólica (PAD) < 80 mmHg; e (GII) pré-hipertensos (n = 19), 54 ± 1 anos, PAS de 139 e PAD de 89 mmHg. RESULTADOS: Após 24 meses de programa de condicionamento físico, os indivíduos do GII apresentaram redução na PAS (-3,6 ± 0,94 e -10 ± 0,94 mmHg, p < 0,05, respectivamente) e PAD (-6,5 ± 1 e -7,1 ± 0,9 mmHg, p < 0,05). Em ambos os grupos houve redução do perímetro de cintura (-1,74 ± 3,5 e -1,91 ± 4 cm, p < 0,05) e índice de adiposidade (-1,21 ± 2,6 e -1,35 ± 3,1%, p < 0,05), aumento da massa corporal (+1,27 ± 3 e +1,32 ± 3,8 kg, p < 0,05), IMC (+0,72 ± 0,4 e +0,54 ± 0,60 kg/m2, p < 0,05) e massa corporal isenta de gordura (+0,91 ± 0,5 e +0,77 ± 4,8 kg p < 0,05). CONCLUSÃO: Este programa reduziu PA, o perímetro de cintura e o índice de adiposidade em indivíduos pré-hipertensos, constituindo-se, portanto, numa estratégia segura e de baixo custo na prevenção de doenças cardiovasculares e melhoria da condição de saúde da população.

The relationship between serum C-reactive protein and daily physical activity in Japanese hypertensive patients

Hypertension (HT) and C-reactive protein (CRP) are risk factors of cardiovascular diseases (CVD). The current study's purpose was to investigate the relationship between serum CRP levels and daily lifestyles, including physical activity, in Japanese HT patients. Lifestyle factors, blood pressure (BP), blood cholesterol, glucose, and CRP were measured in a total of 312 HT patients (153 men/159 women, mean age: 62.6 y). Women with physical activity of ≥ 1 time/week showed significantly lower CRP levels than those without it (p < 0.05). The data suggest that regular physical activity could reduce the CRP levels in HT patients, thereby maybe preventing CVD.

The role of stress and social support in predicting depression among a hypertensive African American sample

OBJECTIVE

We examined social support, stress, and selected demographic variables as predictors of depression among African Americans with hypertension.

METHODS

Archival data collected on 194 hypertensive African Americans ranging in age from 30 to 88 years (mean age = 58.3 years, standard deviation = 12.2; 63% were female) were analyzed in the present study. Hierarchic regression analyses were conducted using two models of depression. The first model included basic demographic characteristics of the sample, including age, sex, educational attainment, income, and employment status. In the second model, the psychosocial variables of stress and social support were added to determine their predictive value.

RESULTS

The first model accounted for 14% of the variance in depression and identified sex and age as significant predictors. The second model, in which two psychosocial variables were added, accounted for 45.2% of the total variance, with age, stress, and social support as significant predictors.

CONCLUSIONS

Stress and social support are significant predictors of depression in a hypertensive African American population, beyond the influence of various demographic variables. These results have implications for prevention and intervention strategies with the target population.

Hypertension in aging: physical activity as primary prevention

In most physiologic systems, there is considerable evidence that the normal aging processes do not result in significant impairment or dysfunction in the absence of pathology and under resting conditions. However, in response to a stress, the age-related reduction in physiologic reserves causes a loss of regulatory or homeostatic balance. This happens before an individual notices that something is wrong. An additional consequence of age-related changes is an increased perception of effort associated with submaximal work. Thus, a vicious cycle is set up, leading to decreasing exercise capacity, resulting in an elevated perception of effort, subsequently causing avoidance of activity, and finally feeding back to exacerbation of the age-related declines secondary to disuse. Sedentary behavior is an important risk factor for chronic disease morbidity and mortality in aging. However, there is a limited amount of information on the type and amount of activity needed to promote optimal health and function in older people [19]. The purpose of this review is to discuss the important role of exercise training as a primary prevention tool to hypertension. In addition, this review will address the topic of the recommended amount of physical activity required for health promotion along with the current exercise guidelines.

Twenty-four hour ambulatory blood pressure monitoring to evaluate effects on blood pressure of physical activity in hypertensive patients

OBJECTIVE

Elevated blood pressure is an important risk factor for cardiovascular disease and stroke. Several studies have demonstrated that physical exercise reduces blood pressure levels in hypertensive subjects and improves control of several well-known risk factors for atherosclerosis such as diabetes mellitus, blood lipid profile and obesity. Our group attempted to evaluate if an exercise program based on periodic controlled fast walking sessions would reduce blood pressure levels in hypertensive subjects.

DESIGN

We enrolled hypertensive subjects not suffering from obesity (Body Mass Index < 30) already under pharmacological therapy; in these subjects we performed a six-week program of mobility exercise based on fast walking.

SETTING

Secondary care.

PATIENTS

We enrolled 189 subjects; 168 subjects completed the training period. Entry criteria were Stage I WHO hypertension in pharmacological treatment, BMI < 30, and absence of any pathological condition resulting in reduced mobility.

INTERVENTIONS

A six-week mobility program centered on fast walking.

MAIN OUTCOME MEASUREMENTS

Systolic and diastolic blood pressure levels before and after the walking program.

RESULTS

Mean 24 h systolic blood pressure changed from 143.1 to 135.5 mmHg. Mean 24 h diastolic blood pressure changed from 91.1 to 84.8 mmHg.

CONCLUSIONS

This reduction, evaluated with Ambulatory Blood Pressure Monitoring (ABPM), confirms that physical exercise should be a part of lifestyle changes for the management of hypertension both in untreated hypertensive patients or high-risk subjects for hypertension, and also for hypertensive patients in association with pharmacological therapy.

Intake of fruits, vegetables, and dairy products in early childhood and subsequent blood pressure change

BACKGROUND

Diets characterized by high intakes of fruits and vegetables and low-fat dairy products (for example, the DASH diet) have been shown to reduce blood pressure in adults. The effects of similar diets on children's blood pressure are unknown.

METHODS

We used 8 years of follow-up data from 95 children, initially 3 to 6 years of age at enrollment in the prospective Framingham Children's Study in 1986. The yearly clinic visits included 5 measures of blood pressure obtained with an automated device. Diet was assessed by means of replicate sets of 3-day food diaries during each year.

RESULTS

Children who consumed more fruits and vegetables (4 or more servings per day) or more dairy products (2 or more servings per day) during the preschool years had smaller yearly gains in systolic blood pressure throughout childhood. By the time of early adolescence, children with higher intakes of fruits and vegetables and dairy products had an adjusted mean (+/- standard deviation) systolic blood pressure of 106 +/- 2.9 mm Hg, whereas those with lower intakes in both food groups had a mean systolic blood pressure of 113 +/-1.5 mm Hg. Those with higher intakes of fruits and vegetables alone or dairy alone had intermediate levels of systolic blood pressure in adolescence. The effects on diastolic blood pressure were weaker.

CONCLUSION

These results suggest that a diet rich in fruits, vegetables, and dairy products may have beneficial effects on blood pressure during childhood.

Lifestyle and dietary modification for prevention of heart failure

This article discusses the factors that contribute most to systolic and diastolic heart failure (HF): ischemic heart disease, hypertension,obesity, diabetes, and nephropathy. Diabetes often follows the insulin resistance syndrome in which obesity and hypertension are combined with dyslipidemia, and obesity is likely causal. Diabetes and hypertension are common causes of nephropathy, which in turn is a common precursor to HF. Insulin resistance, obesity,dyslipidemia, diabetes, and hypertension are risk factors for atherosclerotic coronary disease and left ventricular ischemia. Each is also a risk factor for diastolic dysfunction.

Position of the American Dietetic Association: Integration of medical nutrition therapy and pharmacotherapy

It is the position of the American Dietetic Association that the application of medical nutrition therapy (MNT) and lifestyle counseling as a part of the Nutrition Care Process is an integral component of the medical treatment for management of specific disease states and conditions and should be the initial step in the management of these situations. If optimal control cannot be achieved with MNT alone and concurrent pharmacotherapy is required, then The Association promotes a team approach to care for clients receiving concurrent MNT and pharmacotherapy and encourages active collaboration among dietetics professionals and other members of the health care team. There are a number of medical conditions, many of them chronic, that will respond to MNT and, therefore, MNT should be the first intervention for these conditions. In addition to being a vital element of the optimal management and control of these conditions, MNT is also a cost-effective method of management. However, because of the long-term nature of these conditions, concurrent pharmacotherapy may become necessary to achieve or maintain optimal control. In cases where this is necessary, MNT should continue to be an integral component of the therapy because it may complement or enhance the therapeutic effectiveness of pharmacotherapy, thereby reducing or eliminating the need for multiple medications. The utilization of a coordinated multidisciplinary team approach is critical to the success of the concurrent use of MNT and pharmacotherapy because of the long-term duration of the treatments, the necessity of monitoring compliance and effectiveness, and the likelihood of multiple medication-nutrient interactions.

Effects of mild aerobic physical exercise on membrane fluidity of erythrocytes in essential hypertension

1. The present study was undertaken to investigate the effects of aerobic physical exercise on membrane function in mild essential hypertension. 2. Hypertensive patients were divided into an exercise group (n = 8) and a non-exercise (control) group (n = 8). Physical exercise within the intensity of the anaerobic threshold level was performed twice a week for 6 months. Membrane fluidity of erythrocytes was examined by means of electron paramagnetic resonance (EPR) and spin-labelling methods before and after the trial period in both groups. 3. After physical exercise, blood pressure decreased significantly. 4. Compared with the non-exercise group, in the exercise group both the order parameter (S) and the peak height ratio (ho/h-1) in the EPR spectra of erythrocytes were significantly reduced (S, 0.717 +/- 0.004 vs 0.691 +/- 0.008, respectively (n = 8), P < 0.05; ho/h-1, 5.38 +/- 0.06 vs 4.89 +/- 0.06, respectively (n = 8), P < 0.05). These findings indicated that exercise increased membrane fluidity and improved the membrane microviscosity of erythrocytes. 5. There was no direct correlation between blood pressure reduction and the exercise-induced increase in membrane fluidity of erythrocytes. 6. In the non-exercise (control) group, blood pressure and membrane fluidity were not changed after a 6 month follow-up period. 7. The results show that aerobic physical exercise increased erythrocyte membrane fluidity and improved the rigidity of cell membranes in hypertensive patients. The improvement of rheological properties of erythrocytes may explain, in part, the cellular mechanisms for the beneficial effects of physical exercise in hypertension.

Nutritional supplementation with Chlorella pyrenoidosa for mild to moderate hypertension

Pharmacological treatment of hypertension reduces the risk of cardiovascular disease; however, randomized, controlled clinical trials and population studies have also shown that abnormally high blood pressure (BP) can be lowered with diet modification and exercise. The objective of this pilot study was to determine whether daily dietary supplementation with 10 g Chlorella tablets and 100 ml Chlorella extract for 2 months would reduce BP in subjects with a mean sitting diastolic BP (SiDBP) between 90 and 115 mm Hg. Thirty-three people were enrolled and underwent a 4-week washout period from all antihypertensive medications, during which they consumed placebo. At completion of this washout/placebo period, 24 subjects were considered evaluable (i.e., had a SiDBP between 90 and 115 mm Hg) and were continued in the study. After 1 or 2 months of dietary Chlorella supplementation, the average heart rate, sitting systolic BP, and SiDBP changed only slightly; after 2 months of Chlorella consumption, the group's mean SiDBP was 96.5 +/- 6.6. However, a heterogenous response pattern to Chlorella existed, with 25% (6/24) of the subjects achieving their BP goal (SiDBP less than 90 mm Hg). Furthermore, the BP of nonresponders did not increase significantly above washout values. Quality-of-life questionnaires indicated an overall perception that health had significantly improved in conjunction with Chlorella consumption. The results indicate that, for some subjects with mild to moderate hypertension, a daily dietary supplement of Chlorella reduced or kept stable their SiDBP.

Therapeutic lifestyle changes for hypertension and cardiovascular risk reduction

Elevated blood pressure is the most common chronic illness in the United States, affecting more than 50 million people. Hypertension is an even greater problem in the African American community. Traditionally, management of hypertension and cardiovascular risk reduction has focused on drug therapy; however, several studies have shown the benefits of therapeutic lifestyle changes for blood pressure lowering and cardiovascular risk reduction. Therapeutic lifestyle changes to reduce blood pressure have enormous potential as a means for preventing and controlling hypertension and thereby reducing the risk of coronary heart disease. Although the reductions in blood pressure are relatively modest with these approaches, they could potentially have a beneficial impact on overall cardiovascular morbidity and mortality when applied to the whole population. Because of their high prevalence of certain cardiovascular risk factors (e.g., obesity, diabetes mellitus) and greater salt sensitivity, therapeutic lifestyle changes have particular relevance for African Americans.

Postexercise hypotension in conscious SHR is attenuated by blockade of substance P receptors in NTS

In hypertensive subjects, a single bout of dynamic exercise results in an immediate lowering of blood pressure back toward normal. This postexercise hypotension (PEH) also occurs in the spontaneously hypertensive rat (SHR). In both humans and SHRs, PEH features a decrease in sympathetic nerve discharge, suggesting the involvement of central nervous system pathways. Given that substance P is released in the nucleus tractus solitarius (NTS) by activation of baroreceptor and skeletal muscle afferent fibers during muscle contraction, we hypothesized that substance P acting at neurokinin-1 (NK-1) receptors in the NTS might contribute to PEH. We tested the hypothesis by determining, in conscious SHRs, whether NTS microinjections of the NK-1 receptor antagonist SR-140333 before exercise attenuated PEH. The antagonist, in a dose (60 pmol) that blocked substance P- and spared D,L-homocysteic acid-induced depressor responses, significantly attenuated the PEH by 37%, whereas it had no effect on blood pressure during exercise. Vehicle microinjection had no effect. The antagonist also had no effect on heart rate responses during both exercise and the PEH period. The data suggest that a substance P (NK-1) receptor mechanism in the NTS contributes to PEH.

GABA(A) receptor activation at medullary sympathetic neurons contributes to postexercise hypotension

A single bout of exercise results in a postexercise hypotension (PEH) that is accompanied by a reduced baroreflex function. Based on the role of rostral ventrolateral medulla (RVLM) neurons in controlling sympathetic nerve activity (SNA) and blood pressure, the role of gamma-aminobutyric acid (GABA) in controlling RVLM neuronal activity, and the reduced baroreflex-SNA relationship during PEH, we determined whether: 1) RVLM neuronal activity is decreased during PEH, 2) GABA(A)-receptor mechanisms mediate the decrease, and 3) baroreflex control of RVLM activity is reduced. Spontaneously hypertensive rats (SHR) were subjected to 40 min of treadmill or sham exercise (Sham PEH). PEH lasted 10 h in conscious and anesthetized SHR, indicating that the anesthetics did not affect the expression of PEH. Extracellular RVLM neuronal activity having a cardiac and sympathetic rhythm, lumbar SNA, and blood pressure were recorded at rest and during baroreflex function curves. Resting RVLM neuronal activity was lower and was increased to a greater extent by GABA(A)-receptor antagonism in PEH versus Sham PEH (P < 0.05). Baroreflex control of RVLM neuronal activity operated with a reduced gain (P < 0.05). Thus increased GABA signaling at RVLM neurons may contribute to PEH.

Estrogen and exercise interact to regulate brain-derived neurotrophic factor mRNA and protein expression in the hippocampus

We investigated the possibility that estrogen and exercise interact in the hippocampus and regulate brain-derived neurotrophic factor (BDNF), a molecule increasingly recognized for its role in plasticity and neuron function. An important aspect of this study is to examine the effect of different time intervals between estrogen loss and estrogen replacement intervention. We demonstrate that in the intact female rat, physical activity increases hippocampal BDNF mRNA and protein levels. However, the exercise effect on BDNF up-regulation is reduced in the absence of estrogen, in a time-dependent manner. In addition, voluntary activity itself is stimulated by the presence of estrogen. In exercising animals, estrogen deprivation reduced voluntary activity levels, while estrogen replacement restored activity to normal levels. In sedentary animals, estrogen deprivation (ovariectomy) decreased baseline BDNF mRNA and protein, which were restored by estrogen replacement. Despite reduced activity levels in the ovariectomized condition, exercise increased BDNF mRNA levels in the hippocampus after short-term (3 weeks) estrogen deprivation. However, long-term estrogen-deprivation blunted the exercise effect. After 7 weeks of estrogen deprivation, exercise alone no longer affected either BDNF mRNA or protein levels. However, exercise in combination with long-term estrogen replacement increased BDNF protein above the effects of estrogen replacement alone. Interestingly, protein levels across all conditions correlated most closely with mRNA levels in the dentate gyrus, suggesting that expression of mRNA in this hippocampal region may be the major contributor to the hippocampal BDNF protein pool. The interaction of estrogen, physical activity and hippocampal BDNF is likely to be an important issue for maintenance of brain health, plasticity and general well-being, particularly in women.