Increase in kinins on post-exercise hypotension in normotensive and hypertensive volunteers

Chronobiology of Exercise: Evaluating the Best Time to Exercise for Greater Cardiovascular and Metabolic Benefits

Physiological function fluctuates across 24 h due to ongoing daily patterns of behaviors and environmental changes, including the sleep/wake, rest/activity, light/dark, and daily temperature cycles. The internal circadian system prepares the body for these anticipated behavioral and environmental changes, helping to orchestrate optimal cardiovascular and metabolic responses to these daily changes. In addition, circadian disruption, caused principally by exposure to artificial light at night (e.g., as occurs with night-shift work), increases the risk for both cardiovascular and metabolic morbidity and mortality. Regular exercise is a countermeasure against cardiovascular and metabolic risk, and recent findings suggest that the cardiovascular benefits on blood pressure and autonomic control are greater with evening exercise compared to morning exercise. Moreover, exercise can also reset the timing of the circadian system, which raises the possibility that appropriate timing of exercise could be used to counteract circadian disruption. This article introduces the overall functional relevance of the human circadian system and presents the evidence surrounding the concepts that the time of day that exercise is performed can modulate the cardiovascular and metabolic benefits. Further work is needed to establish exercise as a tool to appropriately reset the circadian system following circadian misalignment to preserve cardiovascular and metabolic health. © 2022 American Physiological Society. Compr Physiol 12:3621-3639, 2022.

Myocardial angiogenesis induced by exercise training involves a regulatory mechanism mediated by kinin receptors

OBJECTIVE

To demonstrate that the kallikrein-kinin system (KKS) is upstream of angiogenic signaling pathway, and to determine the role of the kinin B1 and B2 receptors in myocardial angiogenesis induced by exercise training.

METHODS

Forty Wistar rats were randomly assigned to an exercise control (EC) group, a B1 receptor antagonist (B1Ant) group, a B2 receptor antagonist (B2Ant) group, and a double receptor antagonist ((B1+ B2)Ant) group. A myocardial infarction model was employed. Animals in all groups received 30 min of exercise training for 4 weeks. The expression of VEGF and eNOS, capillary supply, and apoptosis rate were evaluated.

RESULTS

The mRNA and protein expression of VEGF and eNOS showed similar trends in all groups, and were lowest in the (B1+ B2) Ant group, and highest in the EC group. Levels of VEGF and eNOS mRNA were significantly lower in the B1Ant group than in the B2Ant group (p< .001 and p< .05, respectively). VEGF and eNOS protein in the B1Ant group was also significantly lower (p< .01 and p< .05, respectively) than in the B2Ant group. The capillary numbers in the (B1+ B2) Ant group were significantly lower than in the EC group (395.8 ± 105 vs. 1127.9 ± 192.98, respectively). The apoptosis rate of cardiomyocytes was highest in the (B1+ B2) Ant group.

CONCLUSION

KKS may act as an upstream signal transduction pathway for angiogenic factors in myocardial angiogenesis. The B1 and B2 receptors exert additive effects, and the B1 receptor has the most prominent role in mediating KKS-induced myocardial angiogenesis.

Effects of ACEi and ARB on post-exercise hypotension induced by exercises conducted at different times of day in hypertensive men

BACKGROUND

Post-exercise hypotension (PEH) is greater after evening than morning exercise, but antihypertensive drugs may affect the evening potentiation of PEH. Objective: To compare morning and evening PEH in hypertensives receiving angiotensin-converting enzyme inhibitors (ACEi) or angiotensin II receptor blockers (ARB).

METHODS

Hypertensive men receiving ACEi (n = 14) or ARB (n = 15) underwent, in a random order, two maximal exercise tests (cycle ergometer, 15 watts/min until exhaustion) with one conducted in the morning (7 and 9 a.m.) and the other in the evening (8 and 10 p.m.). Auscultatory blood pressure (BP) was assessed in triplicate before and 30 min after the exercises. Changes in BP (post-exercise - pre-exercise) were compared between the groups and the sessions using a two-way mixed ANOVA and considering P < .05 as significant.

RESULTS

In the ARB group, systolic BP decrease was greater after the evening than the morning exercise, while in the ACEi group, it was not different after the exercises conducted at the different times of the day. Additionally, after the evening exercise, systolic BP decrease was lower in the ACEi than the ARB group (ARB = -11 ± 8 vs -6 ± 6 and ACEi = -6 ± 7 vs. -8 ± 5 mmHg, evening vs. morning, respectively, P for interaction = 0.014).

CONCLUSIONS

ACEi, but not ARB use, blunts the greater PEH that occurs after exercise conducted in the evening than in the morning.

Dynamic Resistance Training Improves Cardiac Autonomic Modulation and Oxidative Stress Parameters in Chronic Stroke Survivors: A Randomized Controlled Trial

Stroke survivors are at substantial risk of recurrent cerebrovascular event or cardiovascular disease. Exercise training offers nonpharmacological treatment for these subjects; however, the execution of the traditional exercise protocols and adherence is constantly pointed out as obstacles. Based on these premises, the present study investigated the impact of an 8-week dynamic resistance training protocol with elastic bands on functional, hemodynamic, and cardiac autonomic modulation, oxidative stress markers, and plasma nitrite concentration in stroke survivors. Twenty-two patients with stroke were randomized into control group (CG, n = 11) or training group (TG, n = 11). Cardiac autonomic modulation, oxidative stress markers, plasma nitrite concentration, physical function and hemodynamic parameters were evaluated before and after 8 weeks. Results indicated that functional parameters (standing up from the sitting position (P = 0.011) and timed up and go (P = 0.042)) were significantly improved in TG. Although not statistically different, both systolic blood pressure (Δ = −10.41 mmHg) and diastolic blood pressure (Δ = −8.16 mmHg) were reduced in TG when compared to CG. Additionally, cardiac autonomic modulation (sympathovagal balance–LF/HF ratio) and superoxide dismutase were improved, while thiobarbituric acid reactive substances and carbonyl levels were reduced in TG when compared to the CG subjects. In conclusion, our findings support the hypothesis that dynamic resistance training with elastic bands may improve physical function, hemodynamic parameters, autonomic modulation, and oxidative stress markers in stroke survivors. These positive changes would be associated with a reduced risk of a recurrent stroke or cardiac event in these subjects.

Plasma kallikrein-kinin system contributes to peripheral inflammation in temporal lobe epilepsy

Temporal lobe epilepsy (TLE) is a chronic disease, characterized by severe and refractory seizures, triggered in the hippocampus and/or amygdala, disrupting the blood-brain barrier. This disruption can sustain, or aggravate, the epileptic condition. The aim of this study was to evaluate the activation of the kallikrein-kinin system in patients with TLE, as it relates to the maintenance of blood-brain barrier. Human hippocampal sclerotic tissues removed after surgery for seizure control, plasma, and serum were used in the following assays: immunostaining for white blood cells in the TLE hippocampus, C-reactive protein in serum, quantification of plasma kallikrein (PKal) and cathepsin B (CatB) activity in serum and plasma, quantification of C1-inhibitor, analysis of high-molecular-weight kininogen (H-kininogen) fragments, and activation of plasma prekallikrein for comparison with healthy controls. Infiltration of white blood cells in the sclerotic hippocampus and a significant increase in the neutrophil/lymphocyte ratio in the blood of TLE patients were observed. High levels of C-reactive protein (TLE = 1.4 ± 0.3 µg/mL), PKal (TLE = 5.4 ± 0.4 U/mL), and CatB (TLE = 4.9 ± 0.4 U/mL) were also evident in the serum of TLE patients comparing to controls. A strong linear correlation was observed between active CatB and PKal in the serum of TLE patients (r = 0.88). High levels of cleaved H-kininogen and free PKal, and low levels of C1-inhibitor (TLE = 188 ± 12 µg/mL) were observed in the serum of TLE patients. Our data demonstrated that the plasma kallikrein-kinin system is activated in patients with TLE. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/.

Exaggerated post exercise hypotension following concentric but not eccentric resistance exercise: Implications for metabolism

Post exercise hypotension (PEH) is primarily attributed to post-exercise vasodilation via central and peripheral mechanisms. However, the specific contribution of metabolic cost during exercise, independent of force production, is less clear. This study aimed to use isolated concentric and eccentric exercise to examine the role of metabolic activity in eliciting PEH, independent of total work. Twelve participants (6 male) completed upper and lower body concentric (CONC), eccentric (ECC), and traditional (TRAD) exercise sessions matched for work (3 × 10 in TRAD and 3 × 20 in CONC and ECC; all at 65% 1RM). Blood pressure was collected at baseline and every 15 min after exercise for 120 min. Brachial blood flow and vascular conductance were also assessed at baseline, immediately after exercise, and every 30 min after exercise. ⩒O₂ was lower during ECC compared to CONC and TRAD (-2.7 mL/Kg/min ± 0.4 and -2.2 mL/Kg/min ± 0.4, respectively p < 0.001). CONC augmented the PEH response (Peak ΔMAP -3.3 mmHg ± 0.9 [mean ± SE], p = 0.006) through 75 min of recovery and ECC elicited a post-exercise hypertensive response through 120 min of recovery (Peak ΔMAP +4.5 mmHg ± 0.8, p < 0.001). CONC and TRAD elicited greater increases in brachial blood flow post exercise than ECC (Peak Δ brachial flow +190.4 mL/min ± 32.3, +202.3 mL/min ± 39.2, and 69.6 mL/min ± 19.8, respectively, p ≤ 0.005), while conductance increased immediately post exercise in all conditions and then decreased throughout recovery following ECC (-32.9 mL/min/mmHg ± 9.3, p = 0.005). These data suggest that more metabolically demanding concentric exercise augments PEH compared to work-matched eccentric exercise.

Acute citrulline oral supplementation induces greater post-exercise hypotension response in hypertensive than normotensive individuals

ABSTRACT Objective To investigate whether acute citrulline supplementation might influence post-exercise hypotension in normotensive and hypertensive individuals. Methods Following a randomized double-blind design, twenty normotensive (28±7 years, 74±17kg, 1.7±0.09m) and 20 hypertensive individuals (55±12 years, 76±15kg, 1.59±0.09m) were randomly assigned to one of the four experimental groups (Normotensive-Placebo; Normotensive-Citrulline; Hypertensive-Placebo; Hypertensive-Citrulline). The placebo groups ingested 6g of corn starch and the citrulline groups ingested 6g of citrulline dissolved in water. The participants performed 40 minutes of walking/running on a treadmill at 60-70% heart rate reserve. Blood pressure was measured immediately after a 60-min exercise session using an oscillometric device and 24-h ambulatory monitoring. Results The post-exercise hypotension was more pronounced in hypertensives and the Hypertensive-Citrulline group showed a consistent systolic blood pressure reduction during the laboratorial phase, which can be seen by looking at the mean of 60 minutes (-15.01mmHg vs -3.14mmHg [P=0.005]; -4.16mmHg [P=0.009]; -6.30mmHg [P=0.033] in comparison with the Normotensive-Placebo, Normotensive-Citrulline, and Hypertensive-Placebo groups, respectively). During ambulatory blood pressure monitoring, the Hypertensive-Citrulline group showed a significant reduction in systolic blood pressure (-21.05mmHg) in the awake period compared with the Normotensive-Citrulline group (-3.17mmHg [P=0.010]). Conclusion Acute citrulline oral supplementation can induce greater post-exercise hypotension response in hypertensive than normotensive individuals.

Acute responses of hemodynamic and oxidative stress parameters to aerobic exercise with blood flow restriction in hypertensive elderly women

Systemic arterial hypertension has been associated with the majority deaths from cardiovascular disease, especially among the elderly population, and the imbalance between antioxidant and pro-oxidants has been associated with hypertension. This study analyzed the acute responses of cardiorespiratory and oxidative stress parameters to low intensity aerobic exercise (LIAE) with blood flow restriction (BFR) in hypertensive elderly women. The experimental group consisted of 16 hypertensive women (67.2 ± 3.7 years) who underwent a progressive treadmill test and performed three exercise protocols in random order: high intensity (HIAE), low intensity aerobic exercise (LIAE) and low intensity aerobic exercise with blood flow restriction (LIAE + BFR). Data analysis showed that blood pressure and heart rate augmented from rest to post effort (p < 0.05) and reduced from post effort to recovery (p < 0.05) in all protocols. The values of lipid peroxidation were higher after 30 min of recovery when compared to the moment at rest in the LILIAE + BFR (p < 0.05). The same occurred with glutathione-S-transferase and superoxide dismutase activity. However, non-protein thiols levels (NPSH) reduced after 30 min of recovery when compared to the moment at rest in the LILIAE + BFR protocol (p < 0.05). In the HIAE and LIAE + BFR protocols, the levels of NPSH were lower at 30 min of recovery when compared to the same moment in the LIAE protocol (p < 0.05). LIAE + RBF produces an oxidative status and hemodynamic stimulus similar to HIAE. Taken together, these results support the indication of LIAE with BFR in chronic intervention protocols, with potential benefits for the hypertensive elderly population.

Low blood pressure is sustained during subsequent activities of daily living performed after power training in older women

The present study aimed to examine the effects of a prior session of power training on blood pressure values during tasks that mimic the activities of daily living in hypertensive and normotensive older women. A randomized crossover experimental design was used for this study. Eleven older women (age, 66.1±1.2 years; body mass index, 26.7±4.8 kg/m²; systolic blood pressure, 133.9±23.4 mmHg) were recruited to participate. Volunteers were randomly underwent to a single session of physical exercise equalized by training volume, characterized by 3 sets of 8–10 repetitions in 8 different exercises. However, Power training session was performed at a higher intensity (moderate) than Sham session (rest/very, very easy ). Immediately after the end of the exercise session, subjects were assigned to perform five tasks that mimic the activities of daily living. Hemodynamic parameters were recorded before and immediately after the session of physical exercise, as well as in the end of each of the tasks. Results demonstrated significant elevations in systolic blood pressure and pulse pressure values during the performance of the tasks after the Sham session. However, values were not altered in the power training session. Data of the present study indicate that an acute session of power training can maintain blood pressure values lower during the subsequent performance of tasks that mimic activities of daily living in older women.

Acute and chronic effects of aerobic exercise on blood pressure in resistant hypertension: study protocol for a randomized controlled trial

BACKGROUND

Resistant hypertension is a specific condition that affects approximately 10% of subjects with hypertension, and is characterized by persistently high blood pressure levels even using therapy of three or more antihypertensive agents or with blood pressure control using therapy with four or more antihypertensive agents. Changes in lifestyle, such as physical exercise, are indicated for controlling blood pressure. However, investigating studies about this therapy in individuals with resistant hypertension are few.

METHODS/DESIGN

This is a randomized controlled clinical trial. Forty-eight patients with resistant hypertension will be submitted to perform four short-term interventions: aerobic exercise sessions (mild-, moderate- and high-intensity) and control session, in random order and on separate days. After the short-term sessions, the patients will be randomly allocated into four groups for 8 weeks of follow-up: mild-, moderate- and high-intensity aerobic exercise, and a control group. The primary outcome is the occurrence of blood pressure reduction (office and ambulatory analysis, and acute and chronic effects). Secondary outcomes are autonomic and hemodynamic mechanisms: cardiac and vasomotor autonomic modulation, spontaneous baroreflex sensitivity, forearm blood flow and vascular resistance.

DISCUSSION

The importance of exercise for hypertension has been known for decades, but little is known about the effects on patients with resistant hypertension. This study will help to understand whether different aerobic exercise intensities can induce different responses, as well as by what mechanisms adjustments in blood pressure levels may occur.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02670681 . Registered on 28 January 2016 (first version); Brazilian Registry Platform Clinical Trials: protocol RBR-5q24zh . Registered on 24 June 2015.

POWERLIFTING SESSIONS PROMOTE SIGNIFICANT POST-EXERCISE HYPOTENSION

ABSTRACT Introduction: Powerlifting (PWL) is a worldwide method, frequently used in resistance training programs. However, the relationship between cardiovascular responses and PWL is still unclear in the literature. Objective: To evaluate acute cardiovascular overload and post-exercise hypotension (PEH) after acute powerlifting exercise session in subjects with experience in the modality. Methods: Nine powerlifting athletes (34 ± 5 years) participated voluntarily in this study. The following exercises were used in the session: squat, bench press and deadlift (95% of 1 RM, 2 to 5 repetitions). The anthropometric parameters and blood pressure (systolic, diastolic and mean) were evaluated immediately, 5', 10', 30', 60' and 24 hours after the exercise session with a non-invasive automatic pressure monitor. Results: Significant differences (p<0.05) were found between rest and immediately after exercise on systolic (135 ± 6 vs. 153 ± 10 mmHg) and mean (102 ± 3 vs. 108 ± 3 mmHg) blood pressures, but no difference was found at diastolic (85 ± 3 vs. 85 ± 4 mmHg) blood pressure. Additionally, the increase in systolic pressure did not reach values considered as a risk of cardiovascular overload. Significant PEH was found after 60 minutes (systolic: -12 ± 12%, diastolic: -5 ± 6% and mean: -7 ± 5%) and 24 hours after PWL session (systolic: -5 ± 4%, diastolic: -8 ± 4% and mean: -7 ± 3%). Conclusion: Our data demonstrated that a PWL session does not increase systolic blood pressure up to the risk range and promotes PEH after 60 minutes of exercise and that this cardiovascular response persisted after 24 hours post-exertion in powerlifting athletes.

Blood pressure and autonomic responses following isolated and combined aerobic and resistance exercise in hypertensive older women

PURPOSE

This study aimed to compare blood pressure (BP) after isolated and combined sessions of aerobic and resistance exercises in hypertensive older women. Heart rate (HR) and heart rate variability (HRV) were included as additional variables.

METHODS

Twenty-one older women (63±1.9 years; 69.9±2.7 kg; 158.8±2.1 cm) with controlled hypertension (resting BP = 132.2 ± 3.1/74.1 ± 4.0 mmHg) performed four random sessions on different days: 1) aerobic exercise (AE: treadmill walking/running; 40 min; 50-60% HR_reserve); 2) resistance exercise (RE: 8 exercises; 3 sets; 15 reps; 40% 1RM)); 3) aerobic exercise followed by resistance exercise (A+R); 4); control (CON). BP, HR and HRV were measured at rest and during 180 min after the sessions.

RESULTS

The AE and A+R sessions demonstrated significant decreases in SBP and DBP (30, 60, 120, and 180 min; P < 0.05) and increases in HR (30 and 60 min; P < 0.05) compared to the CON. The RE session demonstrated significant reductions compared to the CON only for DBP (120 and 180 min; P < 0.05). No significant differences were observed in HRV between resting and all sessions.

CONCLUSION

All sessions that involved aerobic exercise (AE and A+R) caused postexercise hypotension in comparison to the CON, with no differences in HRV.

Contact Karate Promotes Post-Exercise Hypotension in Young Adult Males

Background

Worldwide, systemic arterial hypertension is a leading cause of death and non-communicable cardiovascular disease. A major factor contributing to this disease is a sedentary lifestyle. However, physical exercise, such as martial arts, may be an option for blood pressure (BP) control. The magnitude of post-exercise hypotension is associated with a prolonged decrease in BP in normotensive and hypertensive individuals.

Objectives

The present study aimed to verify the effects of a Contact Karate (CK) session on BP responses during a post-exercise recovery period in young adults.

Patients and Methods

Thirty-two male CK athletes volunteered (28.2 ± 6.7 years; 77.0 ± 5.7 kg; and 176.0 ± 4.7 cm) and underwent one CK session (50 minutes) and a control session in which no exercise was performed and the individuals remain seated during the whole time. BP was measured during rest (before sessions), as well as on the 15th, 30th, 45th, and 60th minutes of the post-exercise recovery.

Results

The systolic (SBP), diastolic (DBP), and mean arterial pressure (MAP) were significantly lower at the post-exercise period compared to pre-exercise rest (P < 0.05), with the largest reductions being observed at the 60th minutes of recovery [SBP (rest: 125.9 ± 4.7 vs. 60th minutes of recovery: 111.7 ± 5.4 mmHg); DBP (rest: 78.8 ± .7 vs. 60th minutes of recovery: 69.8 ± 2.7 mmHg)] and at the same periods of post-exercise recovery of the control session.

Conclusions

A single CK session can promote a decrease in BP for at least 60 minutes after performing this type of exercise in young adults.

The blood pressure-lowering effect of a single bout of resistance exercise: A systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Current exercise guidelines recommend aerobic types of exercises on most days of the week, supplemented with dynamic resistance exercise twice weekly. Whereas the blood pressure (BP)-lowering effects of a single session of aerobic exercise have been well studied, less is known about the hypotensive effect of a single bout of resistance exercise.

OBJECTIVES

To evaluate the transient effect of resistance exercise on BP by means of meta-analytic techniques.

METHODS

A systematic electronic search in Medline, Scientific Electronic Library Online (SciELO), Latin American and Caribbean Health Sciences Literature (LILACS), Elton B Stephens Company (EBSCO), EMBASE and SPORTDiscus was completed in March 2015 identifying randomised controlled trials investigating the effect of a single bout of resistance exercise on resting or ambulatory BP in healthy adults. A subsequent meta-analysis was performed.

RESULTS

The meta-analysis involved 30 studies, 81 interventions and 646 participants (normotensive (n = 505) or hypertensive (n = 141)). A single bout of resistance exercise elicited small-to-moderate reductions in office systolic BP at 60 minutes postexercise [-3.3 (-4.0 to -2.6)/-2.7 (-3.2 to -2.1) mmHg (CI 95%)], 90 minutes postexercise [-5.3 (-8.5 to -2.1)/-4.7 (-6.9 to -2.4) mmHg (CI 95%)] and in 24-hour ambulatory BP [-1.7 (-2.8 to -0.67)/-1.2 (-2.4 to -0.022) mmHg (CI 95%)] compared to a control session. The reduction in office BP was more pronounced in hypertensive compared to normotensive individuals (p < 0.01), when using larger muscle groups (p < 0.05) and when participants were recovering in the supine position (p < 0.01).

CONCLUSION

A single bout of resistance exercise can have a BP-lowering effect that last for up to 24 hours. Supine recovery and the use of larger muscle groups resulted in greater BP reductions after resistance exercise.

Effects of exercise intensity on postexercise hypotension after resistance training session in overweight hypertensive patients

Among all nonpharmacological treatments, aerobic or resistance training (RT) has been indicated as a significantly important strategy to control hypertension. However, postexercise hypotension responses after intensity alterations in RT are not yet fully understood. The purpose of this study was to compare the outcomes of differing intensities of RT on hypertensive older women. Twenty hypertensive older women participated voluntarily in this study. After a maximum voluntary contraction test (one repetition maximum) and determination of 40% and 80% experimental loads, the protocol (3 sets/90″ interset rest) was performed in a single session with the following exercises: leg press, leg extension, leg curl, chest press, elbow flexion, elbow extension, upper back row, and abdominal flexion. Systolic and diastolic blood pressures were evaluated at rest, during exercise peak, and after 5, 10, 15, 30, 45, and 60 minutes of exercise and compared to the control. Both experimental loads were effective (P<0.01) in promoting postexercise systolic hypotension (mmHg) compared to controls, after 30, 45, and 60 minutes, respectively, at 40% (113±2, 112±4, and 110±3 mmHg) and 80% (111±3, 111±4, and 110±4 mmHg). Both procedures promoted hypotension with similar systolic blood pressures (40%: -11%±1.0% and 80%: -13%±0.5%), mean arterial blood pressures (40%: -12%±5.5% and 80%: -12%±3.4%), and rate-pressure products (40%: -15%±2.1% and 80%: -17%±2.4%) compared to control measures (systolic blood pressure: 1%±1%, mean arterial blood pressure:\ 0.6%±1.5%, rate-pressure product: 0.33%±1.1%). No differences were found in diastolic blood pressure and heart rate measures. In conclusion, hypertensive older women exhibit postexercise hypotension independently of exercise intensity without expressed cardiovascular overload during the session.

The period of the day affects the twenty-four hour blood pressure response to an acute combined exercise session in Brazilian jiu jitsu athletes

AbstractThe purpose of this study was to compare the effect of a combined exercise session performed at different periods of the day on the 24h blood pressure (BP) response. Anaerobic threshold (AT) and 12 repetition maximum (12RM) tests were evaluated in nine Brazilian jiu-jitsu athletes (male) (22±3.7 y; 176±5.0 cm; 73.4±9.7 kg; 6.8±2.1 % body fat). Four experimental sessions were performed: resistance exercise followed by aerobic exercise [Morning (MornS) and Afternoon (AfternS)] and Control (C) [Morning and Afternoon]. The morning sessions were conducted at 09:00 a.m. and the afternoon sessions were conducted at 3:00 p.m. The resistance exercise consisted of three sets at 90% of a 12RM for six resistance exercises. The aerobic exercise consisted of 15min at 90% of the AT. Blood pressure (BP) was measured before, during and 1h (Microlife(r) BP3A1C) after the performance of exercises in laboratory, and then during daily activities for the succeeding 23h by ambulatory BP monitoring (Dyna-MAPA(r)). Analysis of the area under the curve (AUC) indicated significant reductions in blood pressure parameters at various time points during the 24h monitoring period. For systolic BP (SBP), significantly lower values were shown following the morning session versus the control (MornS: 1756.2±100.8 vs. C: 1818.2±84.3 mmHg*15h; p < .05) and total-24h (MornS: 2695.8±143.3 vs. C: 2784.1±143.2 mmHg*24h; p < .05). The total-24h mean BP (MAP) was also significantly lower following the morning session versus the control (MornS: 2015.7±121.2 vs. C: 2087.3±153.8 mmHg*24h; p < .05). There were significant differences in the sleeping AUC of SBP (AfternS: 883.6±27.0 vs. C: 965.2±67.9 mmHg*9h; p< .05), diastolic BP (DBP) (AfternS: 481.4±30.9 vs. MornS: 552.9±34.2 and C: 562.1±52.3 mmHg*9h; p < .01) and MBP (AfternS: 651.9±22.4 vs. MornS: 708.7±43.1 and C: 726.9±64.7 mmHg*9h; p < .01). The combined exercise performed at different periods of the day contributed distinctly to the reduction of BP. The morning session was important in reducing SBP and MBP in the total-24h monitoring, while the afternoon session reduced SBP, DBP and MBP during sleeping in jiu-Jitsu athletes.

Effects of diaphragm respiration exercise on pulmonary function of male smokers in their twenties

[Purpose] We investigated how diaphragm respiration exercises can affect pulmonary function in long-term male smokers in their twenties. [Subjects and Methods] Twenty-eight healthy males between 20 and 29 years of age were randomly divided into an experimental and a control group (14 members each). The experiment was conducted during 30 min sessions, 3 times a week for 4 weeks. The experimental group performed diaphragm respiration exercises and the control group performed exercises using MOTOmed. Pulmonary function (tidal volume, breathing capacity, inspiratory reserve volume, inspiratory capacity, and expiratory reserve volume) was evaluated and analyzed before and after the experiment. [Results] Our results revealed significant increases in tidal volume, inspiratory reserve volume, inspiratory capacity, and breathing capacity in the experimental group. These increases were greater in the experimental group than in the control group. [Conclusion] In our study, the experimental group which performed diaphragm respiration exercises showed a greater improvement in pulmonary function compared with the control group. It is hypothesized that greater improvement in pulmonary function is expected if diaphragm respiration exercises are implemented taking into account the age of the smokers.

Post-exercise hypotension of normotensive young men through track running sessions

INTRODUCTION: After a single session of physical exercise the blood pressure is reduced (post-exercise hypotension, PHE) and it has been considered as a non-pharmacological mechanism to control the blood pressure. When the exercise is performed since youth it can prevent or avoid hypertension. However, it is important to consider studies with clear practical applications to optimize its reproducibility on a daily basis. OBJECTIVE: Analyze the PEH of normotensive and physically active young men after two track running sessions (maximum and submaximal). METHODS: Participated in this study 62 physically active young men (23.3 ± 4.2 years old; 75.5 ± 9.8 kg; 177.7 ± 5.5 cm; 12.0 ± 4.6% body fatF; 52.4 ± 4.0 mL.kg-1.min-1oxygen uptake), which performed a maximum laboratory exercise test for determination of maximal oxygen uptake (VO2max - aerobic power) and subsequently three randomly running sessions (maximum - T1600; submaximal - T20; control - CON), with 48h interval between themselves. Blood pressure (BP) was measured each 15min during a 60 min period after sessions. RESULTS: Both the maximum and the submaximal exercise lead to PEH. The post-exercise values of systolic blood pressure and diastolic blood pressure differed from resting value in session T20 (p<0.05). The same pattern occurred after T1600 (p<0.05), evidenced from 30th minute post-exercise. The CON did not result in PEH. The magnitude of decay for the mean BP at the 45th after maximum exercise was higher than the other sessions (p<0.05). CONCLUSION: We concluded that both maximum and submaximal exercises, performed on a track running condition, caused PEH in young normotensive and physically active men.

Effects of aerobic exercise intensity on 24-h ambulatory blood pressure in individuals with type 2 diabetes and prehypertension

[Purpose] To verify the effects of different intensities of aerobic exercise on 24-hour ambulatory blood pressure (BP) responses in individuals with type 2 diabetes mellitus (T2D) and prehypertension. [Subjects and Methods] Ten individuals with T2D and prehypertension (55.8 ± 7.7 years old; blood glucose 133.0 ± 36.7 mg·dL⁻¹ and awake BP 130.6 ± 1.6/ 80.5 ± 1.8 mmHg) completed three randomly assigned experiments: non-exercise control (CON) and exercise at moderate (MOD) and maximal (MAX) intensities. Heart rate (HR), BP, blood lactate concentrations ([Lac]), oxygen uptake (VO₂), and rate of perceived exertion (RPE) were measured at rest, during the experimental sessions, and during the 60 min recovery period. After this period, ambulatory blood pressure was monitored for 24 h. [Results] The results indicate that [Lac] (MAX: 6.7±2.0 vs. MOD: 3.8±1.2 mM), RPE (MAX: 19±1.3 vs. MOD: 11±2.3) and VO₂peak (MAX: 20.2±4.1 vs. MOD: 14.0±3.0 mL·kg⁻¹·min⁻¹) were highest following the MAX session. Compared with CON, only MAX elicited post-exercise BP reduction that lasted for 8 h after exercise and during sleep. [Conclusion] A single session of aerobic exercise resulted in 24 h BP reductions in individuals with T2D, especially while sleeping, and this reduction seems to be dependent on the intensity of the exercise performed.

Type 2 diabetes elicits lower nitric oxide, bradykinin concentration and kallikrein activity together with higher DesArg(9)-BK and reduced post-exercise hypotension compared to non-diabetic condition

This study compared the plasma kallikrein activity (PKA), bradykinin concentration (BK), DesArg(9)-BK production, nitric oxide release (NO) and blood pressure (BP) response after moderate-intensity aerobic exercise performed by individuals with and without type 2 diabetes. Ten subjects with type 2 diabetes (T2D) and 10 without type 2 diabetes (ND) underwent three sessions: 1) maximal incremental test on cycle ergometer to determine lactate threshold (LT); 2) 20-min of constant-load exercise on cycle ergometer, at 90% LT and; 3) control session. BP and oxygen uptake were measured at rest and at 15, 30 and 45 min post-exercise. Venous blood samples were collected at 15 and 45 minutes of the recovery period for further analysis of PKA, BK and DesArg(9)-BK. Nitrite plus nitrate (NOx) was analyzed at 15 minutes post exercise. The ND group presented post-exercise hypotension (PEH) of systolic blood pressure and mean arterial pressure on the 90% LT session but T2D group did not. Plasma NOx increased ~24.4% for ND and ~13.8% for T2D group 15 min after the exercise session. Additionally, only ND individuals showed increases in PKA and BK in response to exercise and only T2D group showed increased DesArg(9)-BK production. It was concluded that T2D individuals presented lower PKA, BK and NOx release as well as higher DesArg(9)-BK production and reduced PEH in relation to ND participants after a single exercise session.

Acute and chronic effects of resistance exercise on blood pressure in elderly women and the possible influence of ACE I/D polymorphism

This study investigated the chronic effect of blood pressure (BP) and post-exercise hypotension (PEH) during resistance training (RT) and its relation with the angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism in hypertensive elderly women. Participants were divided into two groups: an experimental group (EG) with exercise and a control group (CG) without exercise. The EG performed one adaptation month and one repetition maximum load (1RM) test at the end of this period. After the first month, the EG conducted a three-month program of RT at 60%, 70%, and 80% of 1RM, respectively, for each month. The CG was evaluated at the end of each month. Systolic (SBP) and diastolic (DBP) blood pressure (Microlife BP 3AC1-1) were measured, with the subject in a seated position, during an acute session for both GE and CG as follows: every 5 minutes for 20 minutes at pre-exercise rest, immediately after the resistance exercise and control, and every 15 minutes during 1 hour of recovery after exercise and CG. Analysis of covariance showed reduction in SBP and DBP (P ≤ 0.05) rest values after the RT program. PEH was observed only for the EG in acute sessions, for SBP after the second and third months (P ≤ 0.05), and for DBP after the second and fourth months (P ≤ 0.05). No significant differences in main effects and interaction effects between blood pressure and ACE I/D were observed. The occurrence of chronic reduction of blood pressure and PEH through EG may have a protective effect on the cardiovascular system with no ACE I/D polymorphism influence for this population.

Isometric handgrip does not elicit cardiovascular overload or post-exercise hypotension in hypertensive older women

BACKGROUND

Arterial hypertension is a serious health problem affecting mainly the elderly population. Recent studies have considered both aerobic and resistance exercises as a non-pharmacological aid for arterial hypertension treatment. However, the cardiovascular responses of the elderly to isometric resistance exercise (eg, isometric handgrip [IHG]) have not yet been documented.

OBJECTIVE

The purpose of this study was to investigate cardiovascular responses to different intensities of isometric exercise, as well as the occurrence of post-isometric exercise hypotension in hypertensive elderly people under antihypertensive medication treatment.

PATIENTS AND METHODS

Twelve women volunteered to participate in the study after a maximal voluntary contraction test (MVC) and standardization of the intervention workload consisting of two sessions of IHG exercise performed in four sets of five contractions of a 10-second duration. Sessions were performed both at 30% of the MVC and 50% of the MVC, using a unilateral IHG protocol. Both intensities were compared with a control session without exercise. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) at rest (R), during peak exercise (PE), and after 5, 10, 15, 30, 45, and 60 minutes of post-exercise recovery were evaluated.

RESULTS

No significant changes were observed after isometric exercise corresponding to 30% MVC for either SBP (R: 121 ± 10; PE: 127 ± 14; 5 min: 125 ± 13; 10 min: 123 ± 12; 15 min: 122 ± 11; 30 min: 124 ± 11; 45 min: 124 ± 10; 60 min: 121 ± 10 mmHg) or DBP (R: 74 ± 9; PE: 76 ± 6; 5 min: 74 ± 5; 10 min: 72 ± 8; 15 min: 72 ± 5; 30 min: 72 ± 8; 45 min: 73 ± 6; 60 min: 75 ± 7 mmHg). Similarly, the 50% MVC did not promote post-isometric exercise hypotension for either SBP (R: 120 ± 7; PE: 125 ± 11; 5 min: 120 ± 9; 10 min: 122 ± 9; 15 min: 121 ± 11; 30 min: 121 ± 9; 45 min: 121 ± 9; 60 min: 120 ± 7 mmHg) or DBP (R: 72 ± 8; PE: 78 ± 7; 5 min: 72 ± 7; 10 min: 72 ± 8; 15 min: 71 ± 7; 30 min: 72 ± 8; 45 min: 75 ± 10; 60 min: 75 ± 7 mmHg).

CONCLUSION

Our data reveal that cardiovascular overload or post-exercise hypotension did not occur in elderly women with controlled hypertension when they undertook an IHG session. Thus this type of resistance exercise, with mild to moderate intensity, with short time of contraction appears to be safe for this population.

Exercise attenuates renal dysfunction with preservation of myocardial function in chronic kidney disease

Previous studies have suggested that exercise improves renal and cardiac functions in patients with chronic kidney disease. The aim of this study was to evaluate the effects of long-term aerobic swimming exercise with overload on renal and cardiac function in rats with 5/6 nefrectomy (5/6Nx). Eight Wistar rats were placed into 4 groups: Control (C), Control+Exercise (E), Sedentary 5/6Nx (NxS) and 5/6Nx+Exercise (NxE). The rats were subjected to swimming exercise sessions with overload for 30 min five days per week for five weeks. Exercise reduced the effect of 5/6Nx on creatinine clearance compared to the NxS group. In addition, exercise minimized the increase in mean proteinuria compared to the NxS group (96.9±10.0 vs. 51.4±9.9 mg/24 h; p<0.05). Blood pressure was higher in the NxS and NxE groups compared to the C and E groups (216±4 and 178±3 vs. 123±2 and 124±2 mm Hg, p<0.05). In the 200 glomeruli that were evaluated, the NxS group had a higher sclerosis index than did the NxE group (16% vs. 2%, p<0.05). Echocardiography demonstrated a higher anterior wall of the left ventricle (LV) in diastole in the NxS group compared with the C, E and NxE groups. The NxS group also had a higher LV posterior wall in diastole and systole compared with the E group. The developed isometric tension in Lmax of the heart papillary muscle was lower in the NxS group compared with the C, E and NxE groups. These results suggested that exercise in 5/6Nx animals might reduce the progression of renal disease and lessen the cardiovascular impact of a reduction in renal mass.

Chronic conventional resistance exercise reduces blood pressure in stage 1 hypertensive men

To investigate the antihypertensive effects of conventional resistance exercise (RE) on the blood pressure (BP) of hypertensive subjects, 15 middle-aged (46 ± 3 years) hypertensive volunteers, deprived of antihypertensive medication (reaching 153 ± 6/93 ± 2 mm Hg systolic/diastolic BP after a 6-week medication washout period) were submitted to a 12-week conventional RE training program (3 sets of 12 repetitions at 60% 1 repetition maximum, 3 times a week on nonconsecutive days). Blood pressure was measured in all phases of the study (washout, training, detraining). Additionally, the plasma levels of several vasodilators or vasoconstrictors that potentially could be involved with the effects of RE on BP were evaluated pre- and posttraining. Conventional RE significantly reduced systolic, diastolic, and mean BP, respectively, by an average of 16 (p < 0.001), 12 (p < 0.01), and 13 mm Hg (p < 0.01) to prehypertensive values. There were no significant changes of vasoactive factors from the kallikrein-kinin or renin-angiotensin systems. After the RE training program, the BP values remained stable during a 4-week detraining period. Taken together, this study shows for the first time that conventional moderate-intensity RE alone is able to reduce the BP of stage 1 hypertensive subjects free of antihypertensive medication. Moreover, the benefits of BP reduction achieved with RE training remained unchanged for up to 4 weeks without exercise.

The higher exercise intensity and the presence of allele I of ACE gene elicit a higher post-exercise blood pressure reduction and nitric oxide release in elderly women: an experimental study

BACKGROUND

The absence of the I allele of the angiotensin converting enzyme (ACE) gene has been associated with higher levels of circulating ACE, lower nitric oxide (NO) release and hypertension. The purposes of this study were to analyze the post-exercise salivary nitrite (NO2-) and blood pressure (BP) responses to different exercise intensities in elderly women divided according to their ACE genotype.

METHODS

Participants (n = 30; II/ID = 20 and DD = 10) underwent three experimental sessions: incremental test - IT (15 watts workload increase/3 min) until exhaustion; 20 min exercise 90% anaerobic threshold (90% AT); and 20 min control session without exercise. Volunteers had their BP and NO2- measured before and after experimental sessions.

RESULTS

Despite both intensities showed protective effect on preventing the increase of BP during post-exercise recovery compared to control, post-exercise hypotension and increased NO2- release was observed only for carriers of the I allele (p < 0.05).

CONCLUSION

Genotypes of the ACE gene may exert a role in post-exercise NO release and BP response.

Exercise lowers blood pressure in university professors during subsequent teaching and sleeping hours

BACKGROUND

University professors are subjected to psychological stress that contributes to blood pressure (BP) reactivity and development of hypertension. The purpose of this study was to investigate the effects of exercise on BP in university professors during teaching and sleeping hours.

METHODS

Twelve normotensive professors (42.2 ± 10.8 years, 74.2 ± 11.2 kg, 172.8 ± 10.4 cm, 20.1% ± 6.7% body fat) randomly underwent control (CONT) and exercise (EX30) sessions before initiating their daily activities. EX30 consisted of 30 minutes of cycling at 80%-85% of heart rate reserve. Ambulatory BP was monitored for 24 hours following both sessions.

RESULTS

BP increased in comparison with pre-session resting values during teaching after CONT (P < 0.05) but not after EX30. Systolic, diastolic, and mean arterial BP showed a more pronounced nocturnal dip following EX30 (approximately -14.7, -12.7, and -9.6 mmHg, respectively) when compared with CONT (approximately -6, -5 and -3 mmHg).

CONCLUSION

Exercise induced a BP reduction in university professors, with the main effects being observed during subsequent teaching and sleeping hours.

Hypotensive response after water-walking and land-walking exercise sessions in healthy trained and untrained women

Background:

The aim of this study was to compare post-exercise hypotension after acute sessions of water-walking and land-walking in healthy trained and untrained women.

Methods:

Twenty-three untrained (n = 12) and trained (n = 11) normotensive women performed two walking sessions in water and on land at 40% of peak VO₂ for 45 minutes. Systolic and diastolic blood pressure and mean arterial pressure were measured 15, 30, 45, and 60 minutes after the exercise sessions.

Results:

No differences were found between the groups for age and anthropometric parameters, but peak VO₂ for the trained women (45 ± 8 mL/kg/minute) was higher than for the untrained women (31 ± 3 mL/kg/minute). No differences were found between the groups with regard to systolic and diastolic blood pressure and mean arterial pressure after water immersion. The heart rate in the trained group (62 ± 3 beats per minute [bpm]) was significantly lower (P < 0.05) than in the untrained group (72 ± 4 bpm) on land, and after water immersion, this difference disappeared (58 ± 5 bpm in the trained women and 66 ± 5 bpm in the untrained women). Sixty minutes after water-walking, systolic blood pressure (108 ± 8 mmHg vs 97 ± 3 mmHg), diastolic blood pressure (69 ± 5 mmHg vs 62 ± 5 mmHg), and mean arterial pressure (82 ± 6 mmHg vs 74 ± 4 mmHg) decreased significantly with rest in the untrained group, and no differences were found after land-walking. In the trained group, significant (P < 0.05) differences were found only for systolic blood pressure (110 ± 9 mmHg vs 100 ± 9 mmHg) after 60 minutes of water-walking; decreases in systolic blood pressure were found after 45 minutes (99 ± 7 mmHg) and 60 minutes (99 ± 6 mmHg) compared with rest (107 ± 5 mmHg) after land-walking.

Conclusion:

Single water-walking and land-walking sessions induced important hypotension following exercise. Additionally, walking performed in chest-deep water has a better effect on exercise-induced hypotension in untrained healthy women than walking at a similar intensity on land.

Cardiovascular and autonomic responses after exercise sessions with different intensities and durations

BACKGROUND

Several studies have reported the phenomenon of post-exercise hypotension. However, the factors that cause this drop in blood pressure after a single exercise session are still unknown.

OBJECTIVE

To investigate the effects of aerobic exercise on the acute blood pressure response and to investigate the indicators of autonomic activity after exercise.

METHODS

Ten male subjects (aged 25 ± 1 years) underwent four experimental exercise sessions and a control session on a cycle ergometer. The blood pressure and heart rate variability of each subject were measured at rest and at 60 min after the end of the sessions.

RESULTS

Post-exercise hypotension was not observed in any experimental sessions (P > 0.05). The index of parasympathetic neural activity, the RMSSD, only remained lower than that during the pre-exercise session after the high-intensity session (Δ = -19 ± 3.7 for 15-20 min post-exercise). In addition, this value varied significantly (P < 0.05) between the high- and low-intensity sessions (Δ = -30.7 ± 4.0 for the high intensity session, and Δ = -9.9 ± 2.5 for the low intensity session).

CONCLUSION

The present study did not find a reduction in blood pressure after exercise in normotensive, physically active young adults. However, the measurements of the indicators of autonomic neural activity revealed that in exercise of greater intensity the parasympathetic recovery tends to be slower and that sympathetic withdrawal can apparently compensate for this delay in recovery.

Post-resistance exercise hypotension in patients with intermittent claudication

OBJECTIVE

To verify the acute effects of resistance exercise on post-exercise blood pressure in patients with intermittent claudication.

METHODS

Eight patients randomly underwent two experimental sessions: a session of resistance exercise (R: 6 exercises, 3 sets of 12, 10 and 8 reps with a perceived exertion of 11 to 13 on the 15-grade Borg scale) and a control session (C: resting on exercise machines).

RESULTS

Before and for 60 min following an intervention, auscultatory blood pressure was measured while subjects rested in a sitting position. After the C session, systolic, diastolic and mean blood pressures did not change from the pre-intervention values, while these values decreased significantly after the R session throughout the entire recovery period (greatest decreases = -14 ± 5, -6 ± 5, and -9 ± 4 mmHg, respectively, P < 0.05).

CONCLUSION

After a single bout of resistance exercise patients with intermittent claudication exhibited reduced systolic, diastolic and mean blood pressures, suggesting that acute resistance exercise may decrease cardiovascular load in these patients.

Acute resistance exercise is more effective than aerobic exercise for 24h blood pressure control in type 2 diabetics

AIM

The study aimed to analyze blood pressure (BP) responses in individuals with type 2 diabetes (T2D) over a 24h period following resistance (RES) and aerobic (AER) exercise.

METHODS

Ten adults with T2D (age: 55.8 ± 7.7 years; weight: 79.4 ± 14.0 kg; fasting glucose: 133.0 ± 36.7 mg.dL⁻¹) underwent: (1) AER: 20 min of cycling at 90% lactate threshold (90% LT); (2) RES: three laps of a circuit of six exercises with eight repetitions at 70% 1-RM and 40s of recovery; and (3) a control session of no exercise. Heart rate (HR), and systolic (SBP), diastolic (DBP), mean arterial (MAP) and pulse (PP) BP, as well as lactataemia (Lac), VO(2), respiratory exchange ratio (RER) and rate of perceived exertion (RPE) were measured at rest, during exercise and control (CON) periods, and 60min after interventions. After each session, BP was also monitored over a 24h period.

RESULTS

Peak Lac (RES: 6.4 ± 1.4mM; AER: 3.8 ± 1.2mM), RER (RES: 1.1 ± 0.1; AER: 0.9 ± 0.1) and RPE (RES: 14.0 ± 1.3; AER: 11.0 ± 2.3) were higher following the RES session (P < 0.05). Similar VO₂ (~70% VO(₂peak)) was reached during AER and RES sessions (14.0 ± 3.0 vs 14.3 ± 1.6 mL.kg.min⁻¹; P > 0.05). Compared with CON, only RES elicited post-exercise BP reduction that lasted 8h after exercise. Also, in comparison to pre-exercise rest, the BP dip during sleep was greater following RES (P < 0.05).

CONCLUSION

A single exercise bout decreases BP in T2D patients over a 24h period, with RES being more effective than AER exercise for BP control.

Respostas cardiovasculares pós-exercício de natação

INTRODUÇÃO: A crescente procura da natação como um tratamento não-farmacológico da hipertensão arterial tem aumentado. Objetivo: Analisar as respostas da pressão arterial (PA) após o exercício de natação e durante a rotina diária de trabalho de indivíduos pré-hipertensos. MÉTODOS: Oito indivíduos pré-hipertensos (128,2 ± 7,8 / 77,8 ± 6,0mmHg; 41,8 ± 3,2 anos; 84,7 ± 17,9kg; 180,4 ± 4,8cm; 27,3 ± 5,8kg.m2(-1)) foram submetidos a duas sessões, sendo uma de natação (SN) e a outra de controle (SC). A PA foi medida no repouso pré-exercício e durante 12 horas de recuperação pós-exercício. Na SN, os pacientes nadaram por 45min em uma intensidade moderada a alta (PSE 14,5 ± 1,6), e, durante a SC, os sujeitos permaneceram em repouso na posição sentada pelo mesmo período de tempo. RESULTADOS: ANOVA para medidas repetidas evidenciou diminuição significativa (p < 0,05) na PAS por duas horas após a SN em relação ao repouso, e uma diferença significativa entre os deltas do PAS (Δ - PAS variação na recuperação pós-exercício em relação ao repouso pré-exercício) foi observada entre as sessões na primeira e segunda horas após a recuperação, respectivamente (ΔSS = -10,4 e -9,3 vs. ΔCS = 0,8 e 4,4mmHg, p < 0,05). Nγo houve diferenças significativas da PAD, intra e entre as sessões. CONCLUSÃO: O exercício de natação em intensidade moderada a alta foi eficaz para promover redução da PA pós-exercício em indivíduos hipertensos durante a sua rotina de trabalho.

Change in central kinin B2 receptor density after exercise training in rats

Cardiovascular responses elicited by the stimulation of kinin B2 receptors in the IV cerebral ventricle, paratrigeminal nucleus or in the thoracic spinal cord are similar to those observed during an exercise bout. Considering that the kalikrein-kinin system (KKS) could act on the cardiovascular modulation during behavioral responses as physical exercise or stress, this study evaluated the central B2 receptor densities of Wistar (W) and spontaneously hypertensive rats (SHR) after chronic moderate exercise. Animals were exercise-trained for ten weeks on a treadmill. Afterwards, systolic blood pressure decreased in both trained strains. Animals were killed and the medulla and spinal cord extracted for B2 receptor autoradiography. Trained animals were compared to their sedentary controls. Sedentary groups showed specific binding sites for Hoe-140 (fmol/mg of tissue) in laminas 1 and 2 of the spinal cord, nucleus of the solitary tract (NTS), area postrema (AP), spinal trigeminal tract (sp5) and paratrigeminal nucleus (Pa5). In trained W a significant increase (p<0.05) in specific binding was observed in the Pa5 (31.3%) and NTS (28.2%). Trained SHR showed a significant decrease in receptor density in lamina 2 (21.9%) of the thoracic spinal cord and an increase in specific binding in Pa5 (36.1%). We suggest that in the medulla, chronic exercise could hyper stimulate the KKS enhancing their efficiency through the increase of B2 receptor density, involving this receptor in central cardiovascular control during exercise or stress. In the lamina 2, B2 receptor might be involved in the exercise-induced hypotension.

Effect of type 2 diabetes on plasma kallikrein activity after physical exercise and its relationship to post-exercise hypotension

AIM

The present study was undertaken to determine the effects of type 2 diabetes (T2D) on plasma kallikrein activity (PKA) and postexercise hypotension (PEH).

METHODS

Ten T2D patients (age: 53.6±1.3 years; body mass index: 30.6±1.0kg/m(2); resting blood glucose: 157.8±40.2mgdL(-1)) and 10 non-diabetic (ND) volunteers (age: 47.5±1.0 years; body mass index: 28.3±0.9kg/m(2); resting blood glucose: 91.2±10.5mgdL(-1)) underwent two experimental sessions, consisting of 20min of rest plus 20min of exercise (EXE) at an intensity corresponding to 90% of their lactate threshold (90LT) and a non-exercise control (CON) session. Blood pressure (BP; Microlife BP 3AC1-1 monitor) and PKA were measured during rest and every 15min for 135min of the postexercise recovery period (RP).

RESULTS

During the RP, the ND individuals presented with PEH at 30, 45 and 120min (P<0.05) while, in the T2D patients, PEH was not observed at any time. PKA increased at 15min postexercise in the ND (P<0.05), but not in the T2D patients.

CONCLUSION

T2D individuals have a lower PKA response to exercise, which probably suppresses its hypotensive effect, thus reinforcing the possible role of PKA on PEH.

Plasma Kallikrein and Angiotensin I-converting enzyme N- and C-terminal domain activities are modulated by the insertion/deletion polymorphism

Angiotensin I-converting enzyme (ACE) is recognized as one of the main effector molecules involved in blood pressure regulation. In the last few years some polymorphisms of ACE such as the insertion/deletion (I/D) polymorphism have been described, but their physiologic relevance is poorly understood. In addition, few studies investigated if the specific activity of ACE domain is related to the I/D polymorphism and if it can affect other systems. The aim of this study was to establish a biochemical and functional characterization of the I/D polymorphism and correlate this with the corresponding ACE activity. For this purpose, 119 male brazilian army recruits were genotyped and their ACE plasma activities evaluated from the C- and N-terminal catalytic domains using fluorescence resonance energy transfer (FRET) peptides, specific for the C-domain (Abz-LFK(Dnp)OH), N-domain (Abz-SDK(Dnp)P-OH) and both C- and N-domains (Abz-FRK(Dnp)P-OH). Plasma kallikrein activity was measured using Z-Phe-Arg-AMC as substrate and inhibited by selective plasma kallikrein inhibitor (PKSI). Some physiological parameters previously described related to the I/D polymorphism such as handgrip strength, blood pressure, heart rate and BMI were also evaluated. The genotype distribution was II n=27, ID n=64 and DD n=28. Total plasma ACE activity of both domains in II individuals was significantly lower in comparison to ID and DD. This pattern was also observed for C- and N-domain activities. Difference between ID and DD subjects was observed only with the N-domain specific substrate. Blood pressure, heart rate, handgrip strength and BMI were similar among the genotypes. This polymorphism also affected the plasma kallikrein activity and DD group presents high activity level. Thus, our data demonstrate that the I/D ACE polymorphism affects differently both ACE domains without effects on handgrip strength. Moreover, this polymorphism influences the kallikrein-kinin system of normotensive individuals.

Are decreases in insular regional cerebral blood flow sustained during postexercise hypotension?

Regional cerebral blood flow (rCBF) in the insular cortex (IC), a well-recognized site for central blood pressure (BP) modulation, is decreased at minute 10 during postexercise hypotension (PEH).

PURPOSE

To determine whether exercise-induced decreases in IC rCBF are associated with BP changes throughout PEH.

METHODS

Ten subjects were studied on three different days using a counterbalanced design with a randomized order for conditions; all were tested during a resting baseline and then at two of three time points postexercise: 10, 30, and 60 min. Data were collected for HR, mean BP, and rCBF using single-photon emission computed tomography as an index of brain activation.

RESULTS

Using ANOVA across conditions, there were differences (P < 0.05; mean +/- SD) for HR from baseline at minute 10 (+15 +/- 4 bpm) and minute 30 (+6 +/- 3 bpm) and for mean BP at minute 10 (-11 +/- 4 mm Hg) and minute 30 (-5 +/- 3 mm Hg). There were significant decreases (P < 0.05) in rCBF at both minutes 10 and 30 after exercise in the inferior thalamus and the right inferior IC regions. Although there were no decreases in BP or IC activity at minute 60, changes in right inferior posterior IC activity and BP were strongly correlated (r2 = 0.74; P < 0.05) postexercise.

CONCLUSIONS

Findings show that exercise-induced decreases in IC and thalamic activity may be a significant neural factor contributing to at least the first 30 min of PEH.

Hipotensão pós-exercício aeróbio: uma revisão sistemática

Diversos estudos investigaram os efeitos hipotensores após uma sessão de exercício aeróbio em humanos. No entanto, vários aspectos permanecem obscuros em relação à hipotensão pós-exercício (HPE), uma vez que diversas variáveis podem influenciar a resposta hipotensora, como intensidade, duração, tipo de exercício, estado clínico, faixa etária, etnia, sexo e estado de treinamento. Nesse sentido, o objetivo do presente estudo foi revisar sistematicamente a literatura, relacionando as principais variáveis da prescrição de uma sessão de exercício aeróbio e a HPE, assim como apresentar os possíveis mecanismos envolvidos. Foram encontrados 55 estudos que abrangeram a temática HPE e exercício aeróbio em humanos. A ocorrência da HPE está bem estabelecida na literatura, já que vários estudos identificaram reduções da pressão arterial em normotensos e hipertensos. Porém, os possíveis moduladores das respostas hipotensoras, como intensidade e duração da sessão de exercício, ainda são contraditórios. Em relação ao tipo de exercício, porém, existem indicativos de que os realizados de forma intermitente e que utilizam maior massa muscular podem acarretar maior HPE. Além disso, hipertensos devem apresentar maior magnitude e duração da HPE. Contudo, existem lacunas em relação aos diversos mecanismos fisiológicos envolvidos, que parecem ser diferentes entre normotensos e hipertensos.