The aim of the present study was to assess systemic circulatory and tissue activities of both the classical arm and of the alternative arm of the renin-angiotensin system (RAS) in a new transgenic rat line (TG7371) that expresses angiotensin-(1-7) (ANG 1-7)-producing fusion protein; the results were compared with the activities measured in control transgene-negative Hannover Sprague-Dawley (HanSD) rats. Plasma and tissue concentrations of angiotensin II (ANG II) and ANG 1-7, and kidney mRNA expressions of receptors responsible for biological actions of ANG II and ANG 1-7 [i.e. ANG II type 1 and type 2 (AT1 and AT2) and Mas receptors] were assessed in TG7371 transgene-positive and in HanSD rats. We found that male TG7371 transgene-positive rats exhibited significantly elevated plasma, kidney, heart and lung ANG 1-7 concentrations as compared with control male HanSD rats; by contrast, there was no significant difference in ANG II concentrations and no significant differences in mRNA expression of AT1, AT2 and Mas receptors. In addition, we found that in male TG7371 transgene-positive rats blood pressure was lower than in male HanSD rats. These data indicate that the balance between the classical arm and the alternative arm of the RAS was in male TGR7371 transgene-positive rats markedly shifted in favor of the latter. In conclusion, TG7371 transgene-positive rats represent a new powerful tool to study the long-term role of the alternative arm of the RAS in the pathophysiology and potentially in the treatment of cardio-renal diseases.
- Keywords
- Angiotensin II, Angiotensin-(1-7), Renin-angiotensin system, TG7371 transgenic rat,
- MeSH
- Angiotensin I * metabolism MeSH
- Angiotensin II * MeSH
- Cardiovascular Diseases metabolism genetics MeSH
- Blood Pressure physiology MeSH
- Rats MeSH
- Kidney metabolism MeSH
- Kidney Diseases metabolism genetics MeSH
- Peptide Fragments * metabolism MeSH
- Rats, Sprague-Dawley * MeSH
- Rats, Transgenic * MeSH
- Proto-Oncogene Mas MeSH
- Receptor, Angiotensin, Type 1 genetics metabolism MeSH
- Receptors, G-Protein-Coupled genetics metabolism MeSH
- Recombinant Fusion Proteins metabolism MeSH
- Renin-Angiotensin System * physiology MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- angiotensin I (1-7) MeSH Browser
- Angiotensin I * MeSH
- Angiotensin II * MeSH
- Peptide Fragments * MeSH
- Proto-Oncogene Mas MeSH
- Receptor, Angiotensin, Type 1 MeSH
- Receptors, G-Protein-Coupled MeSH
- Recombinant Fusion Proteins MeSH
Arterial compliance (AC) is an important cardiovascular parameter characterizing mechanical properties of arteries. AC is significantly influenced by arterial wall structure and vasomotion, and it markedly influences cardiac load. A new method, based on a two-element Windkessel model, has been recently proposed for estimating AC as the ratio of the time constant T of the diastolic blood pressure decay and peripheral vascular resistance derived from clinically available stroke volume measurements and selected peripheral blood pressure parameters which are less prone to peripheral distortions. The aim of this study was to validate AC estimation using a virtual population generated by in silico model of the systemic arterial tree. In the second part of study, we analysed causal coupling between AC oscillations and variability of its potential determinants - systolic blood pressure and heart rate in healthy young human subjects. The pool of virtual subjects (n=3818) represented an extensive AC distribution. AC was estimated from the peripheral blood pressure curve and by the standard method from the aortic blood pressure curve. The proposed method slightly overestimated AC set in the model but both ACs were strongly correlated (r=0.94, p<0.001). In real data, we observed that AC dynamics was coupled with basic cardiovascular parameters variability independently of the autonomic nervous system state. In silico analysis suggests that AC can be reliably estimated by noninvasive method. The analysis of short-term AC variability together with its determinants could improve our understanding of factors involved in AC dynamics potentially improving assessment of AC changes associated with atherosclerosis process. Key words Arterial compliance, Cardiovascular model, Arterial blood pressure, Causal analysis, Volume-clamp photoplethysmography.
- MeSH
- Arteries * physiology MeSH
- Vascular Resistance physiology MeSH
- Adult MeSH
- Blood Pressure * physiology MeSH
- Humans MeSH
- Young Adult MeSH
- Models, Cardiovascular * MeSH
- Computer Simulation * MeSH
- Compliance MeSH
- Heart Rate physiology MeSH
- Vascular Stiffness physiology MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Validation Study MeSH
Sympathetic hyperactivity and relative NO deficiency are characteristic alterations in both genetic and salt hypertension. The contribution of these abnormalities to blood pressure (BP) maintenance can be determined in conscious rats using a consecutive blockade of particular vasoactive systems. Thus, the contribution of pressor effects of angiotensin II to the maintenance of high BP is usually small, but the role of renin-angiotensin system in the development of hypertension mediated by central and peripheral effects of angiotensin II on sympathetic activity is highly important. This is even true in angiotensin-dependent hypertension of heterozygous Ren-2 transgenic rats in which sympathetic hyperactivity is increasing with age. Central sympathoexcitation in this hypertensive model can be inhibited by lower losartan doses than peripheral angiotensin II-dependent vasoconstriction. This experimental model also yielded important knowledge on nephroprotective effects of new therapeutic drugs - endothelin receptor type A blockers. A considerable part of sympathetic vasoconstriction is dependent on the interaction of Ca2+ sensitization (RhoA/Rho kinase pathway) and Ca2+ influx (through L-VDCC). The blockade of these pathways prevents a major part of sympathetic vasoconstriction. Ca2+ sensitization seems to be attenuated in genetic hypertension in order to compensate increased Ca2+ influx. In contrast, enhanced Ca2+ sensitization is a hallmark of salt sensitivity in Dahl rats in which salt hypertension is dependent on increased Ca2+ influx. The attention should also be paid to the impairment of arterial baroreflex sensitivity which permits enhanced BP responses to pressor or depressor stimuli. Some abnormalities can be studied in blood vessels isolated from hypertensive rats but neither conduit arteries nor mesenteric resistance arteries represent the vascular beds decisive for the increased peripheral resistance and high BP. Keywords: Sympathetic vasoconstriction, NO-dependent vasodilatation, Calcium sensitization, Calcium influx, Arterial baroreflex, Spontaneously hypertensive rats, Salt hypertensive Dahl rats, Ren-2 transgenic rats, RAS blockade, SNS blockade, NOS inhibition, Endothelin, Vascular contraction and relaxation, Isolated conduit and resistance arteries, EDCF, PGI2, BKCa channels.
- MeSH
- Hypertension * physiopathology metabolism MeSH
- Blood Pressure drug effects physiology MeSH
- Rats MeSH
- Humans MeSH
- Disease Models, Animal MeSH
- Renin-Angiotensin System drug effects physiology MeSH
- Sympathetic Nervous System physiopathology drug effects MeSH
- Vasodilation drug effects physiology MeSH
- Vasoconstriction * drug effects MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
Pulse Wave Velocity (PWV) is widely used to assess arterial elasticity and is an independent risk factor for cardiovascular disease, but it is influenced by multiple factors. Objective is to assess the impact of blood pressure and heart rate on PWV. Twenty healthy young individuals were enlisted as subjects. Real-time blood pressure monitoring was performed by non-invasive continuous blood pressure measuring instrument during the detection of subjects' carotid PWV. During real-time blood pressure monitoring, exercise load caused fluctuations in blood pressure and heart rate, and PWV changes of each subject under different blood pressure and heart rate conditions were recorded simultaneously. Among the 20 subjects, PWV was associated with blood pressure in four subjects and heart rate in one subject. PWV increased with rising blood pressure when the systolic pressure fluctuation range was >=30mmHg, diastolic pressure fluctuation range was >=18mmHg, and mean arterial pressure fluctuation range was >=20mmHg. PWV increased with rising heart rate, when the heart rate fluctuation range was >30 beats/min. Blood pressure and heart rate have some influence on PWV. However, the fluctuation range of blood pressure and heart rate should reach a certain value, the impact is significant. Keywords: Pulse wave velocity, Blood pressure, Heart rate.
- MeSH
- Pulse Wave Analysis * methods MeSH
- Adult MeSH
- Blood Pressure * physiology MeSH
- Humans MeSH
- Blood Pressure Determination methods MeSH
- Young Adult MeSH
- Heart Rate * physiology MeSH
- Vascular Stiffness physiology MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
OBJECTIVE: To explore whether maternal baseline systolic blood pressure (SBP) and diastolic blood pressure (DBP) affect pregnancy outcomes particularly in normotensive women (SBP, 90-139 mm Hg; DBP, 60-89 mm Hg) and hypertensive women undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). DESIGN: Retrospective cohort study. SETTING: Maximum care hospital for reproductive medicine. PATIENT(S): This study included 73,462 patients who underwent IVF/ICSI at the Reproductive and Genetic Hospital of CITIC-Xiangya between January 1, 2016, and November 30, 2020, selected on the basis of pre-established criteria. Analysis was limited to the first transfer cycle of the first stimulation cycle. INTERVENTION: Baseline SBP and DBP. MAIN OUTCOME MEASURE(S): The primary outcome focused on the live birth rate (LBR), with the secondary outcomes including clinical pregnancy rate, ectopic pregnancy rate, first-trimester miscarriage rate, second- or third-trimester fetal loss, and delivery/neonatal/maternal outcomes. Analytic methods included Poisson regression, linear regression, linear mixed-effect model, and restricted cubic spline analysis as appropriate. RESULT(S): For normotensive women, a 10-mm Hg increase in SBP was associated with an adjusted relative risk of 0.988 (95% confidence interval, 0.981-0.995) for live birth likelihood. However, DBP was not significantly associated with LBR after adjustments. The secondary outcomes indicated that increases in SBP and DBP were associated with higher risks of first-trimester miscarriage, gestational diabetes mellitus, and gestational hypertension in the normotensive subset. Sensitivity analyses confirmed these associations between SBP/DBP and LBR, consistent with the main findings even under stricter guidelines and after adjusting for multiple confounders. Subgroup analyses showed variation in the impact of blood pressure on LBR across different demographics and conditions. Consistent with earlier studies on blood pressure and birth outcomes, we found a 10-mm Hg increase in SBP was associated with a 5.4% (adjusted relative risk per 10 mm Hg, 0.946; 95% confidence interval, 0.907-0.986) reduction in LBR in the hypertensive subgroup. CONCLUSION(S): Systolic blood pressure impacted LBR outcomes in normotensive women who underwent IVF/ICSI, which suggests the need for reconsidering blood pressure management guidelines for reproductive-age women, focusing on reproductive health in addition to cardiovascular risk.
- Keywords
- IVF/ICSI, Maternal blood pressure, first-trimester miscarriage rate, live birth rate,
- MeSH
- Adult MeSH
- Fertilization in Vitro * MeSH
- Sperm Injections, Intracytoplasmic * adverse effects MeSH
- Cohort Studies MeSH
- Blood Pressure * physiology MeSH
- Humans MeSH
- Live Birth * MeSH
- Retrospective Studies MeSH
- Pregnancy MeSH
- Pregnancy Rate MeSH
- Pregnancy Outcome epidemiology MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Pregnancy MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
We hypothesized that sympathetic hyperactivity and parasympathetic insuficiency in spontaneously hypertensive rats (SHR) underlie their exaggerated cardiovascular response to acute stress and impaired adaptation to repeated restraint stress exposure compared to Wistar-Kyoto rats (WKY). Cardiovascular responses to single (120 min) or repeated (daily 120 min for 1 week) restraint were measured by radiotelemetry and autonomic balance was evaluated by power spectral analysis of systolic blood pressure variability (SBPV) and heart rate variability (HRV). Baroreflex sensitivity (BRS) was measured by the pharmacological Oxford technique. Stress-induced pressor response and vascular sympathetic activity (low-frequency component of SBPV) were enhanced in SHR subjected to single restraint compared to WKY, whereas stress-induced tachycardia was similar in both strains. SHR exhibited attenuated cardiac parasympathetic activity (high-frequency component of HRV) and blunted BRS compared to WKY. Repeated restraint did not affect the stress-induced increase in blood pressure. However, cardiovascular response during the post-stress recovery period of the 7th restraint was reduced in both strains. The repeatedly restrained SHR showed lower basal heart rate during the dark (active) phase and slightly decreased basal blood pressure during the light phase compared to stress-naive SHR. SHR subjected to repeated restraint also exhibited attenuated stress-induced tachycardia, augmented cardiac parasympathetic activity, attenuated vascular sympathetic activity and improved BRS during the last seventh restraint compared to single-stressed SHR. Thus, SHR exhibited enhanced cardiovascular and sympathetic responsiveness to novel stressor exposure (single restraint) compared to WKY. Unexpectedly, the adaptation of cardiovascular and autonomic responses to repeated restraint was more effective in SHR.
- Keywords
- Adaptation, Adrenal glands, Habituation, Hypertension, Restraint stress,
- MeSH
- Autonomic Nervous System * physiopathology MeSH
- Baroreflex * physiology MeSH
- Restraint, Physical * MeSH
- Adaptation, Physiological * physiology MeSH
- Hypertension * physiopathology MeSH
- Blood Pressure * physiology MeSH
- Rats MeSH
- Rats, Inbred SHR * MeSH
- Rats, Inbred WKY * MeSH
- Stress, Psychological physiopathology MeSH
- Heart Rate * physiology MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Pulse pressure amplification (PPA) is the brachial-to-aortic pulse pressure ratio and decreases with age and cardiovascular risk factors. This individual-participant meta-analysis of population studies aimed to define an outcome-driven threshold for PPA. Incidence rates and standardized multivariable-adjusted hazard ratios (HRs) of cardiovascular and coronary endpoints associated with PPA, as assessed by the SphygmoCor software, were evaluated in the International Database of Central Arterial Properties for Risk Stratification (n = 5608). Model refinement was assessed by the integrated discrimination (IDI) and net reclassification (NRI) improvement. Age ranged from 30 to 96 years (median 53.6). Over 4.1 years (median), 255 and 109 participants experienced a cardiovascular or coronary endpoint. In a randomly defined discovery subset of 3945 individuals, the rounded risk-carrying PPA thresholds converged at 1.3. The HRs for cardiovascular and coronary endpoints contrasting PPA < 1.3 vs ≥1.3 were 1.54 (95% confidence interval [CI]: 1.00-2.36) and 2.45 (CI: 1.20-5.01), respectively. Models were well calibrated, findings were replicated in the remaining 1663 individuals analyzed as test dataset, and NRI was significant for both endpoints. The HRs associating cardiovascular and coronary endpoints per PPA threshold in individuals <60 vs ≥60 years were 3.86 vs 1.19 and 6.21 vs 1.77, respectively. The proportion of high-risk women (PPA < 1.3) was higher at younger age (<60 vs ≥60 years: 67.7% vs 61.5%; P < 0.001). In conclusion, over and beyond common risk factors, a brachial-to-central PP ratio of <1.3 is a forerunner of cardiovascular coronary complications and is an underestimated risk factor in women aged 30-60 years. Our study supports pulse wave analysis for risk stratification.
- Keywords
- Pulse pressure amplification, Waveform analysis, Cardiovascular risk, Population science,
- MeSH
- Pulse Wave Analysis MeSH
- Brachial Artery physiology MeSH
- Adult MeSH
- Cardiovascular Diseases * physiopathology MeSH
- Blood Pressure * physiology MeSH
- Middle Aged MeSH
- Humans MeSH
- Heart Disease Risk Factors MeSH
- Risk Factors MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Meta-Analysis MeSH
BACKGROUND: Current guidelines and consensus documents recommend withdrawal of mineralocorticoid receptor antagonists (MRAs) before primary aldosteronism (PA) subtyping by adrenal vein sampling (AVS), but this practice can cause severe hypokalemia and uncontrolled high blood pressure. Our aim was to investigate if unilateral PA can be identified by AVS during MRA treatment. METHODS: We compared the rate of unilateral PA identification between patients with and without MRA treatment in large data sets of patients submitted to AVS while off renin-angiotensin system blockers and β-blockers. In sensitivity analyses, the between-group differences of lateralization index values after propensity score matching and the rate of unilateral PA identification in subgroups with undetectable (≤2 mUI/L), suppressed (<8.2 mUI/L), and unsuppressed (≥8.2 mUI/L) direct renin concentration levels were also evaluated. RESULTS: Plasma aldosterone concentration, direct renin concentration, and blood pressure values were similar in non-MRA-treated (n=779) and MRA-treated (n=61) patients with PA, but the latter required more antihypertensive agents (P=0.001) and showed a higher rate of adrenal nodules (82% versus 67%; P=0.022) and adrenalectomy (72% versus 54%; P=0.01). However, they exhibited no significant differences in commonly used AVS indices and the area under the receiving operating characteristic curve of lateralization index, both under unstimulated conditions and postcosyntropin. Several sensitivity analyses confirmed these results in propensity score matching adjusted models and in patients with undetectable, or suppressed or unsuppressed renin levels. CONCLUSIONS: At doses that controlled blood pressure and potassium levels, MRAs did not preclude the identification of unilateral PA at AVS. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01234220.
- Keywords
- aldosterone, blood pressure, hyperaldosteronism, hypertension, mineralocorticoid receptor antagonists, renin,
- MeSH
- Adrenalectomy methods MeSH
- Aldosterone blood MeSH
- Mineralocorticoid Receptor Antagonists * therapeutic use MeSH
- Adult MeSH
- Hyperaldosteronism * blood diagnosis drug therapy surgery MeSH
- Blood Pressure physiology drug effects MeSH
- Middle Aged MeSH
- Humans MeSH
- Adrenal Glands * MeSH
- Renin blood MeSH
- Retrospective Studies MeSH
- Case-Control Studies MeSH
- Propensity Score MeSH
- Treatment Outcome MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
Few studies have investigated the hemodynamic mechanism whereby primary hyperaldosteronism causes hypertension. The traditional view holds that hyperaldosteronism initiates hypertension by amplifying salt-dependent increases in cardiac output (CO) by promoting increases in sodium retention and blood volume. Systemic vascular resistance (SVR) is said to increase only as a secondary consequence of the increased CO and blood pressure. Recently, we investigated the primary hemodynamic mechanism whereby hyperaldosteronism promotes salt sensitivity and initiation of salt-dependent hypertension. In unilaterally nephrectomized male Sprague-Dawley rats given infusions of aldosterone or vehicle, we found that aldosterone promoted salt sensitivity and initiation of salt-dependent hypertension by amplifying salt-induced increases in SVR while decreasing CO. In addition, we validated mathematical models of human integrative physiology, derived from Guyton's classic 1972 model - Quantitative Cardiovascular Physiology-2005 and HumMod-3.0.4. Neither model accurately predicted the usual changes in sodium balance, CO, and SVR that normally occur in response to clinically realistic increases in salt intake. These results demonstrate significant limitations with the hypotheses inherent in the Guyton models. Together these findings challenge the traditional view of the hemodynamic mechanisms that cause salt-sensitive hypertension in primary aldosteronism. Key words: Aldosterone, Blood pressure, Salt, Sodium, Rat.
- MeSH
- Aldosterone blood metabolism MeSH
- Hemodynamics * drug effects MeSH
- Hyperaldosteronism * physiopathology metabolism MeSH
- Hypertension * physiopathology etiology MeSH
- Blood Pressure drug effects physiology MeSH
- Rats MeSH
- Sodium Chloride, Dietary * adverse effects MeSH
- Models, Cardiovascular MeSH
- Disease Models, Animal * MeSH
- Rats, Sprague-Dawley * MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Aldosterone MeSH
- Sodium Chloride, Dietary * MeSH
This study aimed to investigate the effects of shift work on sleep quality, cardiovascular function, and physical activity (PA) levels in Taiwanese police officers. Twenty-one male police officers aged 26.9 ± 4.1 years old located in Taipei voluntarily participated in this study. The participants completed the resting heart rate (HR) and hemodynamic variables (e.g. blood pressure, BP) before and after day-time (DTW) and night-time (NTW) shift work phases (5 working days and 2 resting days for each phase). Additionally, an actigraphy was administered to measure PA and sleep patterns in the last 3 working days. The average total sleep time and sleep efficiency were 278.5 ± 79. 6 min and 72.9 ± 10%, respectively, in the NTW phases, which were significantly lower than that in the DTW phases. A comparison of the PA characteristics between the two phases revealed that a lower proportion of moderate-vigorous PA (1.2 ± 0.8%) and a greater proportion of sedentary behaviour PA (74.8 ± 6.4%) was found in the NTW phases. The results of hemodynamic measures demonstrated that the police officers have significantly elevated systolic BP by 3.3% and diastolic BP by 3.9% after the NTW phases. Furthermore, the NTW phases exhibited a significantly higher percentage change ratio of systolic BP and diastolic BP compared to the DTW phases. Compared with the DTW phases, the NTW phase was significantly more likely to report higher decreasing parasympathetic-related HR variability with a range of -5.9% to -7.8%. In conclusion, night-time shift work resulted in negative physiological changes leading to adverse effects on the health and well-being of Taiwanese police officers.
- Keywords
- Circadian, heart rate variability, occupational health, physical activity, sleep,
- MeSH
- Actigraphy MeSH
- Circadian Rhythm * physiology MeSH
- Exercise physiology MeSH
- Adult MeSH
- Blood Pressure * physiology MeSH
- Sleep Quality MeSH
- Humans MeSH
- Young Adult MeSH
- Police * MeSH
- Shift Work Schedule MeSH
- Sleep physiology MeSH
- Heart Rate * physiology MeSH
- Work Schedule Tolerance * physiology MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Taiwan MeSH