RESUMEN
Hypotension is one of the main characteristics of the systemic inflammation, basically caused by endothelial dysfunction. Studies have shown that the amino acid L-kynurenine (KYN) causes vasodilation in mammals, leading to hypotensive shock. In hypotensive shock, when activated by the KYN, the voltage-gated potassium channel encoded by the family KCNQ (Kv7) gene can cause vasodilation. Fructose-1,6-bisphosphate (FBP) it is being considered in studies an anti-inflammatory, antioxidant, immunomodulator, and a modulator of some ion channels (Ca2+, Na+, and K+). We analyzed the effects of KYN and FBP on mean blood pressure (MBP), systolic and diastolic (DBP) blood pressure, and heart rate variability (HRV) in Wistar rats. Results demonstrated that the administration of KYN significant decreased MBP, DBP, and increased HRV. Importantly, the FBP treatment reversed the KYN effects on MBP, DBP, and HRV. Molecular Docking Simulations suggested that KYN and FBP present a very close estimated free energy of binding and the same position into structure of KCNQ4. Our results did demonstrate that FBP blunted the decrease in BP, provoked by KYN. Results raise new hypotheses for future and studies in the treatment of hypotension resulting from inflammation.
Asunto(s)
Presión Sanguínea , Fructosadifosfatos , Frecuencia Cardíaca , Hipotensión , Quinurenina , Ratas Wistar , Animales , Masculino , Ratas , Presión Sanguínea/efectos de los fármacos , Hipotensión/tratamiento farmacológico , Hipotensión/metabolismo , Hipotensión/fisiopatología , Frecuencia Cardíaca/efectos de los fármacos , Fructosadifosfatos/farmacología , Fructosadifosfatos/metabolismo , Quinurenina/metabolismo , Quinurenina/farmacología , Simulación del Acoplamiento MolecularRESUMEN
Blood pressure (BP) reduction occurs after a single bout of exercise, referred to as postexercise hypotension (PEH). The clinical importance of PEH has been advocated owing to its potential contribution to chronic BP lowering, and as a predictor of responders to exercise training as an antihypertensive therapy. However, the mechanisms underlying PEH have not been well defined. This study undertook a scoping review of research on PEH mechanisms, as disclosed in literature reviews. We searched the PubMed, Web of Science, Scopus, Cumulated Index to Nursing and Allied Health Literature (CINAHL), Cochrane Library, and Sport Discus databases until January 2023 to locate 21 reviews - 13 narrative, four systematic with 102 primary trials, and four meta-analyses with 75 primary trials involving 1566 participants. We classified PEH mechanisms according to major physiological systems, as central (autonomic nervous system, baroreflex, cardiac) or peripheral (vascular, hemodynamic, humoral, and renal). In general, PEH has been related to changes in autonomic control leading to reduced cardiac output and/or sustained vasodilation. However, the role of autonomic control in eliciting PEH has been challenged in favor of local vasodilator factors. The contribution of secondary physiological outcomes to changes in cardiac output and/or vascular resistance during PEH remains unclear, especially by exercise modality and population (normal vs. elevated BP, young vs. older adults). Further research adopting integrated approaches to investigate the potential mechanisms of PEH is warranted, particularly when the magnitude and duration of BP reductions are clinically relevant. (PROSPERO CRD42021256569).
Asunto(s)
Ejercicio Físico , Hipotensión Posejercicio , Humanos , Hipotensión Posejercicio/fisiopatología , Ejercicio Físico/fisiología , Presión Sanguínea/fisiología , Sistema Nervioso Autónomo/fisiopatología , Barorreflejo/fisiología , Hemodinámica , Hipotensión/fisiopatologíaRESUMEN
OBJECTIVE: To investigate the circulatory physiology of hypotension during the first day after birth among stable extremely preterm neonates. STUDY DESIGN: Case-control study of neonates born at ≤276/7 weeks gestational age with hypotension, defined as mean blood pressure in mmHg less than gestational age in weeks for at least 1 hour during the first 24 hours after birth, who underwent comprehensive echocardiography assessment before commencement of cardiovascular drugs. Neonates with hypotension (n = 14) were matched by gestational age and intensity of respiratory support with normotensive neonates (n = 27) who underwent serial echocardiography during the first day after birth, and relatively contemporaneous echocardiography assessments were used for comparison. RESULTS: Neonates with hypotension had a higher frequency of patent ductus arteriosus ≥1.5 mm (71% vs 15%; P < .001) and ductal size (median diameter, 1.6 mm [IQR, 1.4-2.1] vs 1.0 mm [IQR, 0-1.3]; P = .002), higher echocardiography indices of left ventricular systolic function (mean shortening fraction, 34 ± 7% vs 26 ± 4%; P < .001; mean longitudinal strain, -16 ± 5% vs -14 ± 3%; P = .04; and mean velocity of circumferential fiber shortening, 1.24 ± 0.35 circ/s vs 1.01 ± 0.28 circ/s; P = .03), lower estimates of left ventricular afterload (mean end-systolic wall stress, 20 ± 7 g/cm2 vs 30 ± 9 g/cm2; P < .001 and mean arterial elastance, 43 ± 19 mmHg/mL vs 60 ± 22 mmHg/mL; P = .01), without significant difference in stress-velocity index z-score (-0.42 ± 1.60 vs -0.88 ± 1.30; P = .33). Neonates with hypotension had higher rates of any degree of intraventricular hemorrhage (71% vs 22%; P = .006). CONCLUSIONS: Low blood pressure in otherwise well extremely low gestational age neonates was associated with low systemic afterload and larger patent ductus arteriosus, but not left ventricular dysfunction.
Asunto(s)
Conducto Arterioso Permeable/epidemiología , Hipotensión/complicaciones , Hipotensión/fisiopatología , Enfermedades del Prematuro/epidemiología , Disfunción Ventricular Izquierda/epidemiología , Factores de Edad , Estudios de Casos y Controles , Femenino , Edad Gestacional , Humanos , Recien Nacido Extremadamente Prematuro , Recién Nacido , MasculinoRESUMEN
Sepsis activates the renin-angiotensin system and the production of angiotensin II, which has a key role in the regulation of blood pressure through AT1 receptors. However, excessive activation of AT1 receptor is associated with deleterious effects. We investigated the consequences of a differential blockade of AT1 receptor caused by two doses of losartan (0.25 mg/kg or 15 mg/kg, s.c), a selective AT1 receptor antagonist on sepsis outcome. These doses reduced the effect of angiotensin II in normal rats by 30% and >90% 8 h after administration, respectively, but only the higher dose maintained its inhibitory effect (~70%) 24 h after injection. Sepsis was induced by cecal ligation and puncture (CLP). Losartan was injected 2 h after CLP and parameters were evaluated 6 and 24 h after CLP. Septic rats developed hypotension and hyporesponsiveness to vasoconstrictors, an intense inflammatory process and increase in plasma markers of organ dysfunction. The lower dose of losartan improved the vasoconstrictive response to phenylephrine and angiotensin II, reduced lung myeloperoxidase and prevented leukopenia 24 h after CLP, but it did not reduce NOS-2 expression, plasma IL-6 levels or organ injury parameters of septic rats. On the other hand, the higher dose of losartan worsened the response to vasoconstrictors, potentiated the hypotension and increased further levels of creatine, urea and lactate in septic rats. Therefore, an early and partial blockade of AT1 receptor with a low dose of losartan may counteract sepsis-induced refractoriness to vasoconstrictors thus providing an opportunity to improve the outcome of this condition.
Asunto(s)
Bloqueadores del Receptor Tipo 1 de Angiotensina II/farmacología , Presión Arterial/efectos de los fármacos , Hipotensión/tratamiento farmacológico , Losartán/farmacología , Sistema Renina-Angiotensina/efectos de los fármacos , Choque Séptico/tratamiento farmacológico , Vasoconstricción/efectos de los fármacos , Vasoconstrictores/farmacología , Angiotensina II/metabolismo , Animales , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Femenino , Hipotensión/metabolismo , Hipotensión/microbiología , Hipotensión/fisiopatología , Mediadores de Inflamación/sangre , Ratas Wistar , Receptor de Angiotensina Tipo 2/efectos de los fármacos , Receptor de Angiotensina Tipo 2/metabolismo , Choque Séptico/metabolismo , Choque Séptico/microbiología , Choque Séptico/fisiopatologíaRESUMEN
PURPOSE: To establish a hypotensive brain death pig model and observe the effects of hypotension on small bowel donors. METHODS: The hypotensive brain death model was produced using the modified intracranial water sac inflation method in ten domestic crossbred pigs. Effects of hypotensive brain death on small bowel tissue morphology were evaluated through changes in intestinal tissue pathology, tight junction protein of the intestinal mucosa and plasma intestinal fatty acid-binding protein (i-FABP) levels. The pathophysiological mechanism was examined based on changes in superior mesenteric artery (SMA) blood flow and systemic hemodynamics. RESULTS: After model establishment, SMA blood flow, and the mean arterial pressure (MAP) significantly decreased, while heart rate increased rapidly and fluctuated significantly. Small bowel tissue morphology and levels of tight junction protein of the intestinal mucosa showed that after model establishment, small bowel tissue injury was gradually aggravated over time (P<0.05). Plasma i-FABP levels significantly increased after brain death (P<0.05). CONCLUSIONS: A hypotensive brain death pig model was successfully established using an improved intracranial water sac inflation method. This method offers a possibility of describing the injury mechanisms more clearly during and after brain death.
Asunto(s)
Muerte Encefálica/fisiopatología , Modelos Animales de Enfermedad , Hipotensión/fisiopatología , Intestino Delgado/patología , Intestino Delgado/trasplante , Animales , Biopsia , Western Blotting , Ensayo de Inmunoadsorción Enzimática , Proteínas de Unión a Ácidos Grasos/sangre , Femenino , Hemodinámica , Intestino Delgado/irrigación sanguínea , Masculino , Microscopía Electrónica de Transmisión , Reproducibilidad de los Resultados , Porcinos , Factores de Tiempo , Proteína de la Zonula Occludens-1/análisisRESUMEN
The main purpose of this work was to construct an energy-dependent response curve of photobiomodulation on arterial pressure in hypertension animal model. To reach this objective, we have used a two-kidney one clip (2K-1C) rat model. Animals received acute laser light irradiation (660 nm) on abdominal region using different energy (0.6, 1.8, 3.6, 7.2, 13.8, 28.2, 55.8, and 111.6 J), the direct arterial pressure was measured by femoral cannulation, and systolic arterial pressure (SAP), diastolic arterial pressure (DAP), heart rate (HR), and time of effect were obtained. Our results indicated that 660 nm laser light presents an energy-dependent hypotensive effect, and 28.2 J energy irradiation reached the maximum hypotensive effect, inducing a decreased SAP, DAP, and HR (decrease in SAP: - 19.23 ± 1.82 mmHg, n = 11; DAP: - 9.57 ± 2.23 mmHg, n = 11; HR: - 39.15 ± 5.10 bpm, n = 11; and time of hypotensive effect: 3068.00 ± 719.00 s, n = 11). The higher energy irradiation evaluated (111.6 J) did not induce a hypotensive effect and induced an increase in HR (21.69 ± 7.89 bpm, n = 7). Taken together, our results indicate that red laser energy irradiation from 7.2 to 55.8 J is the effective therapeutic window to reduce SAP, DAP, MAP, and HR and induce a long-lasting hypotensive effect in rats, with effect loss at higher energy irradiation (111.6 J).
Asunto(s)
Presión Sanguínea , Hipertensión/fisiopatología , Hipertensión/radioterapia , Terapia por Luz de Baja Intensidad , Animales , Presión Sanguínea/efectos de los fármacos , Presión Sanguínea/fisiología , Diástole/fisiología , Frecuencia Cardíaca , Hipotensión/fisiopatología , Masculino , Ratas Wistar , Sístole/fisiologíaRESUMEN
Abstract Introduction: Intradialytic hypotension (IDH) is a major complication of hemodialysis, with a prevalence of about 25% during hemodialysis sessions, causing increased morbidity and mortality. Objective: To study the effects of sertraline to prevent IDH in hemodialysis patients. Methods: This was a double-blind, crossover clinical trial comparing the use of sertraline versus placebo to reduce intradialytic hypotension. Results: Sixteen patients completed the two phases of the study during a 12-week period. The IDH prevalence was 32%. A comparison between intradialytic interventions, intradialytic symptoms, and IDH episodes revealed no statistical difference in the reduction of IDH episodes (p = 0.207) between the two intervention groups. However, the risk of IDH interventions was 60% higher in the placebo group compared to the sertraline group, and the risk of IDH symptoms was 40% higher in the placebo group compared to the sertraline group. Survival analysis using Kaplan-Meier estimator supported the results of this study. Sertraline presented a number needed to treat (NNT) of 16.3 patients to prevent an episode from IDH intervention and 14.2 patients to prevent an episode from intradialytic symptoms. Conclusion: This study suggests that the use of sertraline may be beneficial to reduce the number of symptoms and ID interventions, although there was no statistically significant difference in the blood pressure levels.
Resumo Introdução: A hipotensão intradialítica (HID) é uma das principais complicações da hemodiálise, com uma prevalência de cerca de 25% durante as sessões de hemodiálise, causando aumento da morbimortalidade. Objetivo: Estudar os efeitos da sertralina na prevenção da HID em pacientes em hemodiálise. Métodos: Este foi um ensaio clínico duplo-cego, cruzado, comparando o uso de sertralina versus placebo para reduzir a hipotensão intradialítica. Resultados: Dezesseis pacientes completaram as duas fases do estudo durante um período de 12 semanas. A prevalência de HID foi de 32%. Uma comparação entre intervenções intradialíticas, sintomas intradialíticos (ID) e episódios de HID não revelou diferença estatística na redução dos episódios de HID (p = 0,207) entre os dois grupos de intervenção. No entanto, o risco de intervenções para HID foi 60% maior no grupo placebo em comparação com o grupo Sertralina, e o risco de sintomas ID foi 40% maior no grupo placebo em comparação com o grupo Sertralina. A análise de sobrevida utilizando o estimador de Kaplan-Meier corroborou os resultados deste estudo. A sertralina apresentou um número necessário para tratar (NNT) de 16,3 pacientes para prevenir um episódio de intervenção de HID e 14,2 pacientes para prevenir um episódio de sintomas intradialíticos. Conclusão: Este estudo sugere que o uso de sertralina pode ser benéfico para reduzir o número de sintomas e intervenções de HID, embora não tenha havido diferença estatisticamente significante nos níveis pressóricos.
Asunto(s)
Humanos , Masculino , Femenino , Persona de Mediana Edad , Anciano , Diálisis Renal/efectos adversos , Inhibidores Selectivos de la Recaptación de Serotonina/uso terapéutico , Sertralina/uso terapéutico , Insuficiencia Renal/terapia , Hipotensión/fisiopatología , Placebos/administración & dosificación , Presión Sanguínea/efectos de los fármacos , Presión Sanguínea/fisiología , Método Doble Ciego , Prevalencia , Diálisis Renal/mortalidad , Estudios Cruzados , Insuficiencia Renal/complicaciones , Hipotensión/prevención & control , Hipotensión/epidemiologíaRESUMEN
Abstract Purpose: To establish a hypotensive brain death pig model and observe the effects of hypotension on small bowel donors. Methods: The hypotensive brain death model was produced using the modified intracranial water sac inflation method in ten domestic crossbred pigs. Effects of hypotensive brain death on small bowel tissue morphology were evaluated through changes in intestinal tissue pathology, tight junction protein of the intestinal mucosa and plasma intestinal fatty acid-binding protein (i-FABP) levels. The pathophysiological mechanism was examined based on changes in superior mesenteric artery (SMA) blood flow and systemic hemodynamics. Results: After model establishment, SMA blood flow, and the mean arterial pressure (MAP) significantly decreased, while heart rate increased rapidly and fluctuated significantly. Small bowel tissue morphology and levels of tight junction protein of the intestinal mucosa showed that after model establishment, small bowel tissue injury was gradually aggravated over time (P<0.05). Plasma i-FABP levels significantly increased after brain death (P<0.05). Conclusions: A hypotensive brain death pig model was successfully established using an improved intracranial water sac inflation method. This method offers a possibility of describing the injury mechanisms more clearly during and after brain death.
Asunto(s)
Animales , Masculino , Femenino , Muerte Encefálica/fisiopatología , Modelos Animales de Enfermedad , Hipotensión/fisiopatología , Intestino Delgado/patología , Intestino Delgado/trasplante , Porcinos , Factores de Tiempo , Biopsia , Ensayo de Inmunoadsorción Enzimática , Western Blotting , Reproducibilidad de los Resultados , Microscopía Electrónica de Transmisión , Proteínas de Unión a Ácidos Grasos/sangre , Proteína de la Zonula Occludens-1/análisis , Hemodinámica , Intestino Delgado/irrigación sanguíneaRESUMEN
INTRODUCTION: Intradialytic hypotension (IDH) is a major complication of hemodialysis, with a prevalence of about 25% during hemodialysis sessions, causing increased morbidity and mortality. OBJECTIVE: To study the effects of sertraline to prevent IDH in hemodialysis patients. METHODS: This was a double-blind, crossover clinical trial comparing the use of sertraline versus placebo to reduce intradialytic hypotension. RESULTS: Sixteen patients completed the two phases of the study during a 12-week period. The IDH prevalence was 32%. A comparison between intradialytic interventions, intradialytic symptoms, and IDH episodes revealed no statistical difference in the reduction of IDH episodes (p = 0.207) between the two intervention groups. However, the risk of IDH interventions was 60% higher in the placebo group compared to the sertraline group, and the risk of IDH symptoms was 40% higher in the placebo group compared to the sertraline group. Survival analysis using Kaplan-Meier estimator supported the results of this study. Sertraline presented a number needed to treat (NNT) of 16.3 patients to prevent an episode from IDH intervention and 14.2 patients to prevent an episode from intradialytic symptoms. CONCLUSION: This study suggests that the use of sertraline may be beneficial to reduce the number of symptoms and ID interventions, although there was no statistically significant difference in the blood pressure levels.
Asunto(s)
Hipotensión/fisiopatología , Diálisis Renal/efectos adversos , Insuficiencia Renal/terapia , Inhibidores Selectivos de la Recaptación de Serotonina/uso terapéutico , Sertralina/uso terapéutico , Anciano , Presión Sanguínea/efectos de los fármacos , Presión Sanguínea/fisiología , Estudios Cruzados , Método Doble Ciego , Femenino , Humanos , Hipotensión/epidemiología , Hipotensión/prevención & control , Masculino , Persona de Mediana Edad , Placebos/administración & dosificación , Prevalencia , Diálisis Renal/mortalidad , Insuficiencia Renal/complicaciones , Riesgo , Análisis de SupervivenciaRESUMEN
The search for new drugs remains an important focus for the safe and effective treatment of cardiovascular diseases. Previous evidence has shown that choline analogs can offer therapeutic benefit for cardiovascular complications. The current study investigates the effects of 2-(4-((1-phenyl-1H-pyrazol-4-yl)methyl)piperazin-1-yl)ethan-1-ol (LQFM032) on cardiovascular function and cholinergic-nitric oxide signaling. Synthesized LQFM032 (0.3, 0.6, or 1.2 mg/kg) was administered by intravenous and intracerebroventricular routes to evaluate the potential alteration of mean arterial pressure, heart rate, and renal sympathetic nerve activity of normotensive and hypertensive rats. Vascular function was further evaluated in isolated vessels, while pharmacological antagonists and computational studies of nitric oxide synthase and muscarinic receptors were performed to assess possible mechanisms of LQFM032 activity. The intravenous and intracerebroventricular administration of LQFM032 elicited a temporal reduction in mean arterial pressure, heart rate, and renal sympathetic nerve activity of rats. The cumulative addition of LQFM032 to isolated endothelium-intact aortic rings reduced vascular tension and elicited a concentration-dependent relaxation. Intravenous pretreatment with L-NAME (nitric oxide synthase inhibitor), atropine (nonselective muscarinic receptor antagonist), pirenzepine, and 4-DAMP (muscarinic M1 and M3 subtype receptor antagonist, respectively) attenuated the cardiovascular effects of LQFM032. These changes may be due to a direct regulation of muscarinic signaling as docking data shows an interaction of choline analog with M1 and M3 but not nitric oxide synthase. Together, these findings demonstrate sympathoinhibitory, hypotensive, and antihypertensive effects of LQFM032 and suggest the involvement of muscarinic receptors.
Asunto(s)
Antihipertensivos/farmacología , Hipotensión/fisiopatología , Piperazinas/farmacología , Pirazoles/farmacología , Receptor Muscarínico M1/fisiología , Receptor Muscarínico M3/fisiología , Animales , Aorta Torácica/efectos de los fármacos , Aorta Torácica/fisiología , Atropina/farmacología , Presión Sanguínea/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Hipertensión/inducido químicamente , Masculino , Antagonistas Muscarínicos/farmacología , NG-Nitroarginina Metil Éster/farmacología , Óxido Nítrico Sintasa/antagonistas & inhibidores , Piperidinas/farmacología , Pirenzepina/farmacología , Ratas Endogámicas SHR , Ratas WistarRESUMEN
Electrical stimulation of the carotid baroreflex has been thoroughly investigated for treating drug-resistant hypertension in humans. However, a previous study from our laboratory, performed in conscious rats, has demonstrated that electrical stimulation of the carotid sinus/nerve (CS) activated both the carotid baroreflex as well as the carotid chemoreflex, resulting in hypotension. Additionally, we also demonstrated that the carotid chemoreceptor deactivation potentiated this hypotensive response. Therefore, to further investigate this carotid baroreflex/chemoreflex interaction, besides the hemodynamic responses, we evaluated the respiratory responses to the electrical stimulation of the CS in both intact (CONT) and carotid chemoreceptors deactivated (CHEMO-X) conscious rats. CONT rats showed increased ventilation in response to electrical stimulation of the CS as measured by the respiratory frequency (fR), tidal volume (VT) and minute ventilation (VE), suggesting a carotid chemoreflex activation. The carotid chemoreceptor deactivation abolished all respiratory responses to the electrical stimulation of the CS. Regarding the hemodynamic responses, the electrical stimulation of the CS caused hypotensive responses in CONT rats, which were potentiated by the carotid chemoreceptors deactivation. Heart rate (HR) responses did not differ between groups. In conclusion, the present study showed that the electrical stimulation of the CS, in conscious rats, activates both the carotid baroreflex and the carotid chemoreflex driving an increase in ventilation and a decrease in AP. These findings further contribute to our understanding of the electrical stimulation of CS.
Asunto(s)
Barorreflejo/fisiología , Seno Carotídeo/fisiología , Células Quimiorreceptoras/fisiología , Hemodinámica/fisiología , Respiración , Animales , Barorreflejo/efectos de los fármacos , Células Quimiorreceptoras/efectos de los fármacos , Estado de Conciencia , Estimulación Eléctrica , Hipotensión/fisiopatología , Masculino , Cianuro de Potasio/farmacología , RatasRESUMEN
This work aimed to explore the cardiovascular effects induced by freeze-dried juice from Syzygium jambolanum (Lam.) DC fruits (JSJ). JSJ presented high polyphenol content and steroids. HPLC analysis revealed that 2,5-dihydroxybenzoic and caffeic acid were present in higher amounts in the JSJ extract. In rat, JSJ induces hypotension and vasodilatation in mesenteric arteries, with or without vascular endothelium. JSJ-mediated vasodilation response against contractions induced with KCl (60 mM) depolarizing solution was significantly lower than the responses induced by JSJ when evaluated against phenylephrine-induced contractions. To investigate the involvement of potassium channels we used Tyrode's solution with KCl (20 mM) or tetraethylammonium (1.0, 3.0, or 5.0 mM). In these conditions JSJ-induced effects were significantly attenuated. To investigate the potassium channel subtypes involved in the response, we used 4-aminopyridine, glibenclamide, BaCl2, and iberiotoxin. In the presence (simultaneous) of different potassium channel blockers we observed a significant attenuation of JSJ-induced effect. Inhibition was also observed when using BaCl2, glibenclamide, or 4-aminopyridine, separately. However, incubation with iberiotoxin did not promote changes in either maximum effect, or potency. We also evidenced a discrete participation of CaV channels in the JSJ-induced vasorelaxant effect. In addition, patch-clamp studies demonstrated that JSJ could activate potassium channels. In conclusion, JSJ promotes hypotension and vasorelaxation in rats, involving, at least, the activation of potassium channels.
Asunto(s)
Jugos de Frutas y Vegetales , Hipotensión , Arterias Mesentéricas , Bloqueadores de los Canales de Potasio/farmacología , Canales de Potasio/metabolismo , Syzygium/química , Vasodilatación/efectos de los fármacos , Animales , Liofilización , Hipotensión/inducido químicamente , Hipotensión/metabolismo , Hipotensión/fisiopatología , Arterias Mesentéricas/metabolismo , Arterias Mesentéricas/fisiopatología , Bloqueadores de los Canales de Potasio/química , Ratas , Ratas WistarRESUMEN
PURPOSE: To determine which nocturnal blood pressure (BP) parameters (low levels or extreme dipper status) are associated with an increased risk of glaucomatous damage in Hispanics. DESIGN: Observational cross-sectional study. PARTICIPANTS: A subset (n = 93) of the participants from the Maracaibo Aging Study (MAS) who met the study eligibility criteria were included. These participants, who were at least 40 years of age, had measurements for optical tomography coherence, visual field (VF) tests, 24-hour BP, office BP, and intraocular pressure <22 mmHg. METHODS: Univariate and multivariate logistic regression analyses under the generalized estimating equations (GEE) framework were used to examine the relationships between glaucomatous damage and BP parameters, with particular attention to decreases in nocturnal BP. MAIN OUTCOME MEASURES: Glaucomatous optic neuropathy (GON) based on the presence of optic nerve damage and VF defects. RESULTS: The mean age was 61.9 years, and 87.1% were women. Of 185 eyes evaluated, 19 (26.5%) had signs of GON. Individuals with GON had significantly lower 24-hour and nighttime diastolic BP levels than those without. However, results of the multivariate GEE models indicated that the glaucomatous damage was not related to the average systolic or diastolic BP levels measured over 24 hours, daytime, or nighttime. In contrast, extreme decreases in nighttime systolic and diastolic BP (>20% compared with daytime BP) were significant risk factors for glaucomatous damage (odds ratio, 19.78 and 5.55, respectively). CONCLUSIONS: In this population, the link between nocturnal BP and GON is determined by extreme dipping effects rather than low nocturnal BP levels alone. Further studies considering extreme decreases in nocturnal BP in individuals at high risk of glaucoma are warranted.
Asunto(s)
Envejecimiento/fisiología , Presión Sanguínea/fisiología , Ritmo Circadiano/fisiología , Glaucoma de Ángulo Abierto/fisiopatología , Hipotensión/fisiopatología , Enfermedades del Nervio Óptico/fisiopatología , Anciano , Monitoreo Ambulatorio de la Presión Arterial , Estudios Transversales , Femenino , Glaucoma de Ángulo Abierto/diagnóstico , Gonioscopía , Humanos , Presión Intraocular/fisiología , Masculino , Persona de Mediana Edad , Fibras Nerviosas/patología , Enfermedades del Nervio Óptico/diagnóstico , Células Ganglionares de la Retina/patología , Tomografía de Coherencia Óptica , Tonometría Ocular , Venezuela , Campos Visuales/fisiologíaRESUMEN
Abstract Purpose: To use blood lactate (BL) as an end-point metabolic marker for the begin resuscitation of volume replacement in experimental hemorrhagic shock. Methods: Group I (n=7) was not bled (Control). Animals in Group II (n=7) were bled to a MAP of 30mmHg in thirty minutes. Hemodynamic and metabolic data were recorded at Baseline, at 30, 60 and 120 minutes after Baseline. The animals were intubated in spontaneous breathing (FIO2=0.21) with halothane. Results: Group I all survived. In Group II all died; no mortality occurred before a BL<10mM/L. Beyond the end-point all animals exhibited severe acidemia, hyperventilation and clinical signs of shock. Without treatment all animals died within 70.43±24.51 min of hypotension shortly after reaching an average level of BL 17.01±3.20mM/L. Conclusions: Swine's breathing room air spontaneously in hemorrhagic shock not treated a blood lactate over 10mM/L results fatal. The predictable outcome of this shock model is expected to produce consistent information based on possible different metabolic and hemodynamic patterns as far as the type of fluid and the timing of resuscitation in near fatal hemorrhagic shock.
Asunto(s)
Animales , Resucitación/métodos , Choque Hemorrágico/metabolismo , Choque Hemorrágico/terapia , Ácido Láctico/sangre , Hipotensión/metabolismo , Choque Hemorrágico/fisiopatología , Choque Hemorrágico/mortalidad , Porcinos , Factores de Tiempo , Biomarcadores , Grupos Control , Determinación de Punto Final , Modelos Animales de Enfermedad , Hemodinámica , Hipotensión/fisiopatologíaRESUMEN
BACKGROUND: systemic arterial hypertension is the most prevalent cardiovascular disease; physical activity for hypertensive patients is related to several beneficial cardiovascular adaptations. This paper evaluated the effect of water- and land-ergometry exercise sessions on post-exercise hypotension (PEH) of healthy normotensive subjects versus treated or untreated hypertensive patients. METHODS: Forty-five older women composed three experimental groups: normotensive (N, n = 10), treated hypertensive (TH, n = 15) and untreated hypertensive (UH, n = 20). The physical exercise acute session protocol was performed at 75% of maximum oxygen consumption (VO2max) for 45 minutes; systolic (SBP), diastolic (DBP) and mean (MBP) blood pressure were evaluated at rest, peak and at 15, 30, 45, 60, 75 and 90 minutes after exercise cessation. Additionally, the heart rate variability (HRV) was analyzed by R-R intervals in the frequency domain for the assessment of cardiac autonomic function. RESULTS: In both exercise modalities, equivalent increases in SBP were observed from rest to peak exercise for all groups, and during recovery, significant PEH was noted. At 90 minutes after the exercise session, the prevalence of hypotension was significantly higher in water- than in the land-based protocol. Moreover, more pronounced reductions in SBP and DBP were observed in the UH patients compared to TH and N subjects. Finally, exercise in the water was more effective in restoring HRV during recovery, with greater effects in the untreated hypertensive group. CONCLUSION: Our data demonstrated that water-ergometry exercise was able to induce expressive PEH and improve cardiac autonomic modulation in older normotensive, hypertensive treated or hypertensive untreated subjects when compared to conventional land-ergometry.
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Ejercicio Físico/fisiología , Frecuencia Cardíaca/fisiología , Hipertensión/fisiopatología , Hipotensión/etiología , Presión Sanguínea/fisiología , Estudios de Casos y Controles , Ergometría , Femenino , Humanos , Hipotensión/fisiopatología , Persona de Mediana Edad , Consumo de Oxígeno/fisiologíaRESUMEN
OBJECTIVE/BACKGROUND: The objective was to analyze the acute effects of a single bout of arm cranking exercise on affective and cardiovascular parameters in patients with symptomatic peripheral artery disease (PAD). METHODS: This was a prospective, controlled, crossover study. Eleven men with symptomatic PAD underwent two experimental sessions in a random order: control or arm crank exercise (15 × 2 minutes bouts of arm crank exercise interrupted by 2 minutes rest intervals). During exercise, ratings of perceived exertion (Borg scale) and affective responses (pleasure/displeasure) were obtained at the first, fifth, tenth, and fifteenth bouts. Before and after the experimental sessions, cardiovascular parameters (blood pressure and heart rate) were obtained. Data were analysed by a two-way repeated measure analysis of variance with significance achieved at p < .05. RESULTS: During the arm crank exercise, patients reported positive feelings of pleasure. During exercise, heart rate (HR) remained within 80-90% of peak HR. Additionally, patients performed arm crank exercise with moderate levels of perceived exertion (Borg rating of 11-13) and with pleasant affective scores (Feeling Scale of +1 to +5). Blood pressure (systolic, diastolic, and mean) increase was lower after arm crank exercise than for control (greatest net effect: -15 ± 11 mmHg [p < .001]; -9 ± 5 mmHg [p < .001]; -9 ± 6 mmHg [p < .001], respectively), while HR increased (greatest net effect: +9 ± 6 beats per minute; p < .001). CONCLUSION: A single bout of arm crank exercise promotes pleasurable feelings while reducing blood pressure in patients with symptomatic PAD.
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Presión Sanguínea , Terapia por Ejercicio/métodos , Hipotensión/etiología , Contracción Muscular , Músculo Esquelético/fisiopatología , Enfermedad Arterial Periférica/terapia , Placer , Anciano , Anciano de 80 o más Años , Brasil , Estudios Cruzados , Frecuencia Cardíaca , Humanos , Hipotensión/diagnóstico , Hipotensión/fisiopatología , Masculino , Persona de Mediana Edad , Enfermedad Arterial Periférica/diagnóstico , Enfermedad Arterial Periférica/fisiopatología , Enfermedad Arterial Periférica/psicología , Estudios Prospectivos , Factores de Tiempo , Resultado del Tratamiento , Extremidad SuperiorRESUMEN
PURPOSE: To use blood lactate (BL) as an end-point metabolic marker for the begin resuscitation of volume replacement in experimental hemorrhagic shock. METHODS: Group I (n=7) was not bled (Control). Animals in Group II (n=7) were bled to a MAP of 30mmHg in thirty minutes. Hemodynamic and metabolic data were recorded at Baseline, at 30, 60 and 120 minutes after Baseline. The animals were intubated in spontaneous breathing (FIO2=0.21) with halothane. RESULTS: Group I all survived. In Group II all died; no mortality occurred before a BL<10mM/L. Beyond the end-point all animals exhibited severe acidemia, hyperventilation and clinical signs of shock. Without treatment all animals died within 70.43±24.51 min of hypotension shortly after reaching an average level of BL 17.01±3.20mM/L. CONCLUSIONS: Swine's breathing room air spontaneously in hemorrhagic shock not treated a blood lactate over 10mM/L results fatal. The predictable outcome of this shock model is expected to produce consistent information based on possible different metabolic and hemodynamic patterns as far as the type of fluid and the timing of resuscitation in near fatal hemorrhagic shock.
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Hipotensión/metabolismo , Ácido Láctico/sangre , Resucitación/métodos , Choque Hemorrágico/metabolismo , Choque Hemorrágico/terapia , Animales , Biomarcadores , Grupos Control , Modelos Animales de Enfermedad , Determinación de Punto Final , Hemodinámica , Hipotensión/fisiopatología , Choque Hemorrágico/mortalidad , Choque Hemorrágico/fisiopatología , Porcinos , Factores de TiempoRESUMEN
The effects of exercise training (ExT) on the pressor response elicited by potassium cyanide (KCN) in the rat model of ischemia-induced heart failure (HF) are unknown. We evaluated the effects of ExT on chemoreflex sensitivity and its interaction with baroreflex in rats with HF. Wistar rats were divided into four groups: trained HF (Tr-HF), sedentary HF (Sed-HF), trained sham (Tr-Sham), and sedentary sham (Sed-Sham). Trained animals underwent to a treadmill running protocol for 8 weeks (60 m/day, 5 days/week, 16 m/min). After ExT, arterial pressure (AP), baroreflex sensitivity (BRS), peripheral chemoreflex (KCN: 100 µg/kg body mass), and cardiac function were evaluated. The results demonstrate that ExT induces an improvement in BRS and attenuates the pressor response to KCN relative to the Sed-HF group (P < 0.05). The improvement in BRS was associated with a reduction in the pressor response following ExT in HF rats (P < 0.05). Moreover, ExT induced a reduction in left ventricular end-diastolic pressure and pulmonary congestion compared with the Sed-HF group (P < 0.05). The pressor response to KCN in the hypotensive state is decreased in sedentary HF rats. These results suggest that ExT improves cardiac function and BRS and attenuates the pressor response evoked by KCN in HF rats.
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Presión Sanguínea/efectos de los fármacos , Terapia por Ejercicio , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/terapia , Cianuro de Potasio/farmacología , Animales , Barorreflejo/fisiología , Presión Sanguínea/fisiología , Hiperemia/fisiopatología , Hiperemia/terapia , Hipotensión/inducido químicamente , Hipotensión/fisiopatología , Hígado/irrigación sanguínea , Pulmón/irrigación sanguínea , Masculino , Nitroprusiato/farmacología , Ratas , Disfunción Ventricular Izquierda/terapiaRESUMEN
ß-Citronellol is a monoterpene found in the essential oil of various plants with antihypertensive properties. In fact, ß-citronellol possesses hypotensive actions due to its vasodilator abilities. Here we aimed to show that ß-citronellol recruits airway sensory neural circuitry to evoke cardiorespiratory effects. In anesthetized rats, intravenous injection of ß-citronellol caused biphasic hypotension, bradycardia and apnea. Bilateral vagotomy, perivagal capsaicin treatment or injection into the left ventricle abolished first rapid phase (named P1) but not delayed phase P2 of the ß-citronellol effects. P1 persisted after pretreatment with capsazepine, ondansetron, HC-030031 or suramin. Suramin abolished P2 of apnea. In awake rats, ß-citronellol induced biphasic hypotension and bradycardia being P1 abolished by methylatropine. In vitro, ß-citronellol inhibited spontaneous or electrically-evoked contractions of rat isolated right or left atrium, respectively, and fully relaxed sustained contractions of phenylephrine in mesenteric artery rings. In conclusion, chemosensitive pulmonary vagal afferent fibers appear to mediate the cardiovascular and respiratory effects of ß-citronellol. The transduction mechanism in P1 seems not to involve the activation of transient receptor potential vanilloid subtype 1 (TRPV1), transient receptor potential ankyrin subtype 1 (TRPA1), purinergic (P2X) or 5-HT3 receptors located on airways sensory nerves. P2 of hypotension and bradycardia seems resulting from a cardioinhibitory and vasodilatory effect of ß-citronellol and the apnea from a purinergic signaling.
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Apnea/inducido químicamente , Bradicardia/inducido químicamente , Hipotensión/inducido químicamente , Monoterpenos/farmacología , Monoterpenos Acíclicos , Animales , Apnea/fisiopatología , Presión Arterial/efectos de los fármacos , Función Atrial/efectos de los fármacos , Bradicardia/fisiopatología , Frecuencia Cardíaca/efectos de los fármacos , Hipotensión/fisiopatología , Masculino , Arterias Mesentéricas/efectos de los fármacos , Arterias Mesentéricas/fisiología , Ratas Wistar , Frecuencia Respiratoria/efectos de los fármacos , Vagotomía , Nervio Vago/efectos de los fármacos , Nervio Vago/fisiologíaRESUMEN
Background: Identifying patients at risk of developing severe dengue is challenging. The objective of the present study was to determine the incidence of hypotension and its predictive factors during the Dengue 2 epidemic in 2013. Methods: In 2013, a longitudinal study was performed using data from all confirmed cases of dengue seen in Cayenne General Hospital. The analysis used Cox proportional modeling to obtain adjusted hazards ratios for hypotension. Results: A total of 806 confirmed patients were included 78 (9.6%) of whom developed hypotension. Extensive purpura, cutaneomucous hemorrhage, serous effusion and age 1-15 years were associated with subsequent hypotension whereas 'aches' and a rash were associated with a lower incidence of hypotension. The biological variables independently associated with hypotension were: increase of hematocrit, low protein concentrations, low sodium concentration and lymphocytes over 1400/ml. A risk score was computed from the scaled Cox model coefficient. Conclusions: From a clinician's perspective, extensive purpura, cutaneomucous hemorrhage, serous effusion, age 1-15 years, hematocrit increase, low protein, low sodium, lymphocytosis and the absence of aches or of a rash, may be important warning signs to predict subsequent hypotension and shock. Over half of the patients with the highest risk score subsequently developed hypotension. The prognostic score had a 48.2% sensitivity with less than 10% of false positives. This score requires external validation before its impact on clinical practice is evaluated.