Abstract P129: Role of the Autonomic Nervous System in Remote Postconditioning in Humans

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Rupert P Williams ◽  
Michael I Okorie ◽  
Harminder Gill ◽  
John E Deanfield ◽  
Raymond J MacAllister ◽  
...  

Brief periods of ischaemia activate systemic mechanisms that induce whole-body tolerance to subsequent prolonged and injurious ischaemia. This phenomenon, remote ischaemic preconditioning (RIPC), is sufficiently acute to reduce ischaemia-reperfusion (IR) injury even when applied simultaneously with injurious ischaemia. This aspect of RIPC is termed remote postconditioning (RPostC). We have previously demonstrated a role for the autonomic nervous system in RIPC. Using an in vivo model of endothelial IR injury, we determined if RPostC is dependent on adrenergic autonomic mechanisms. Vascular ultrasound was used to assess endothelial function in healthy volunteers by measuring dilatation of the brachial artery in response to increased blood flow during reactive hyperaemia (flow-mediated dilatation; FMD). Endothelial IR injury was induced by 20 min of upper limb ischaemia (inflation of a blood pressure cuff to 200 mm Hg) followed by reperfusion. RPostC was induced by applying 2 cycles of 5 minutes ischaemia and 5 minutes reperfusion on the leg during arm ischaemia (via a second blood pressure cuff). In order to determine the dependence of RPostC on autonomic activation, we administered the alpha adrenoceptor blocker phentolamine (0.2– 0.7mg/min, intravenously) during the application of the RPostC stimulus. FMD was determined before ischaemia and at 20 minutes of reperfusion. FMD (percentage change from baseline diameter) was compared statistically by ANOVA. IR alone caused a significant reduction in FMD (5.9±0.7% pre- versus 2.2±0.4% post-IR, n=9, P<0.001). This reduction was prevented by RPostC (5.8±0.4% pre- versus 5.4±0.3% post-IR, n=8, P>0.05). Systemic phentolamine blocked the protective effects of RPostC (FMD 6.1±0.5% pre- versus 2.0±0.3% post-IR, n=7, P<0.001). These data indicate, for the first time in humans, that protection from RPostC depends on preservation of adrenergic signalling. Alpha blockade neutralises one of the endogenous mechanisms of ischemic protection in humans; the clinical consequences of this remain to be determined.

Author(s):  
Vladimir A. Fokin ◽  
Dmitrii M. Shlyapnikov ◽  
Svetlana V. Red’ko

In accordance with the requirements of paragraph 3.2.6 of sanitary rules and norms «Sanitary and epidemiological requirements for physical factors at workplace», in the event of exceeding noise level at workplace above 80 dBA, an employer is obliged to assess the health risk of workers and confirm an acceptable risk to their health. The connection between the incidence of occupational and occupationally conditioned diseases with noise exposure exceeding the maximum permissible levels (80 dBA) was estimated. The assessment was carried out at a food industry enterprise of Perm Region. Assessing the relationship between morbidity and noise exposure is the first step in evaluation of occupational health risks for workers exposed to noise exceeding MAL. If a reliable relationship between morbidity and noise exposure is established, an assessment of occupational risk is conducted. The odds ratio (OR) for diseases characterized by high blood pressure and disorders of autonomic nervous system was <1 (confidence interval CI=0.11–1.61 and CI=0.08–2.78, respectively). The relative risk (RR) for diseases characterized by high blood pressure and disorders of autonomic nervous system was <1. The received data testify absence of connection of morbidity with exposure to industrial noise, calculation of etiological share of responses and levels of risk is not required.


2018 ◽  
Vol 89 (11) ◽  
pp. 2187-2198 ◽  
Author(s):  
Tamaki Mitsuno ◽  
Ayaka Kai

A system for measuring clothing pressure employing a renewed hydrostatic pressure-balancing method was examined using three calibration methods. All methods revealed an almost perfectly linear Y = X relation for the pressure load (X) and the reading of the system (Y). In the application, the distributions of elastic band pressure were examined on 21 planes from head to foot. The preferred elastic band pressures of the leg and arm were significantly higher than those of the neck and abdomen. These results are due to the large presence of the autonomic nervous system at the surfaces of the neck and abdomen. In the area of the abdomen, the preferred elastic band pressure was higher from the mammilla to the shoulder than for the anteroposterior midlines. The development of compression ware must consider appropriate tightening for each body part.


2018 ◽  
Vol 1 (21;1) ◽  
pp. E409-E418
Author(s):  
Leandro Nogueira

Background: Patients with chronic musculoskeletal pain have a higher chance of presenting impairment in cardiovascular autonomic modulation, which may have implications for cardiovascular events. The autonomic nervous system plays an important role in pain modulation. However, it is unclear whether patients with inefficient descending nociceptive inhibition have poorer cardiovascular autonomic modulation. Objective: To compare the cardiovascular autonomic modulation of patients with musculoskeletal pain who had normal versus impaired functioning of descending nociceptive inhibitory system (DNIS). Study Design: A cross-sectional study. Setting: Physiotherapy outpatient service. Methods: Fifty-six patients with musculoskeletal pain were included. Conditioned pain modulation was assessed by the difference of algometric values held in the dorsal forearm and tibialis anterior muscle, before and after a thermal pain stimulus was employed via the cold pressure test (CPT). Patients with inefficient DNIS in both sites were classified as impaired responders (n = 14). The others were classified as normal responders (n = 42). Cardiac autonomic modulation was monitored at rest by heart rate variability (HRV). The blood pressure response to the CPT was used as a proxy of sympathetic responsiveness. Results: Most of the patients were women (60%) and had chronic pain (75%). The groups had similar demographic characteristics. Patients with impaired DNIS showed lower HRV [RMSSD (P = 0.020), SDRR (P = 0.009), HF (ms2 ) (P = 0.027), LF (ms2 ) (P = 0.004), and total power (P = 0.002)]. The blood pressure response to CPT was similar between groups (systolic pressure, P = 0.813; diastolic pressure, P = 0.709). Limitation: Physical activity level, emotional changes, and visceral pathologies can alter the autonomic nervous system and may represent potential confounders. The low number of patients may have biased the results. Conclusion: Patients with impaired DNIS presented lower resting HRV, indicating an altered vagal control of the heart. In contrast, the blood pressure response to a sympathoexcitatory stimulus was preserved. The study was approved by the Research Ethics Committee of Augusto Motta University Centre (CAAE number: 46245215.9.0000.5235), and all patients signed the Informed Consent Form. Key words: Musculoskeletal pain, autonomic nervous system, heart rate, chronic pain, diffuse noxious inhibitory control, blood pressure, sympathetic nervous system, parasympathetic nervous system


2019 ◽  
Author(s):  
Ana M. Cruz ◽  
Yasaman Malekizadeh ◽  
Julia M. Vlachaki Walker ◽  
Paul G. Weightman Potter ◽  
Katherine Pye ◽  
...  

ABSTRACTAMP-activated protein kinase (AMPK) is a critical cellular and whole body energy sensor activated by energy stress, including hypoglycemia, which is frequently experienced by people with diabetes. Previous studies using direct delivery of an AMPK activator to the ventromedial hypothalamus (VMH) in rodents increased hepatic glucose production. Moreover, recurrent glucoprivation in the hypothalamus leads to blunted AMPK activation and defective hormonal responses to subsequent hypoglycemia. These data suggest that amplifying AMPK activation may prevent or reduce frequency hypoglycemia in diabetes. We used a novel brain-permeable AMPK activator, R481, which potently increased AMPK phosphorylation in vitro. R481 significantly increased peak glucose levels during glucose tolerance tests in rats, which were attenuated by treatment with AMPK inhibitor SBI-0206965 and completely abolished by blockade of the autonomic nervous system. This occurred without altering insulin sensitivity measured by hyperinsulinemic-euglycemic clamps. Endogenous insulin secretion was not altered by R481 treatment. During hyperinsulinemic-hypoglycemic clamp studies, R481 treatment reduced exogenous glucose requirements and amplified peak glucagon levels during hypoglycemia. These data demonstrate that peripheral administration of the brain permeable AMPK activator R481 amplifies the counterregulatory response to hypoglycemia in rats, which could have clinical relevance for prevention of hypoglycemia.


2010 ◽  
Vol 72 (5) ◽  
pp. 442-449 ◽  
Author(s):  
Jose M. Martinez ◽  
Amir Garakani ◽  
Horacio Kaufmann ◽  
Cindy J. Aaronson ◽  
Jack M. Gorman

1940 ◽  
Vol 43 (2) ◽  
pp. 236-240 ◽  
Author(s):  
E. Gellhorx ◽  
C. W. Darrow ◽  
L. Yesinick

PEDIATRICS ◽  
1951 ◽  
Vol 8 (5) ◽  
pp. 664-671
Author(s):  
NATALIE ARONSON ◽  
GERTRUDE S. STERN ◽  
SIDNEY Q. COHLAN

An eight year old child with intermittent attacks of hypertension and vomiting has been described, The blood pressure fell dramatically in response to Benzodioxane®, suggesting the presence of a pheochromocytoma, but this tumor was not found after an extensive exploratory laparotomy. The episodes of hypertension and vomiting together with the associated findings in this child of crying without tears, frequent blotching of the skin and excessive sweating and salivating are considered to be indications of an unusually labile autonomic nervous system. These latter characteristics were present in a younger sibling who also had an extremely labile blood pressure but who did not exhibit periodic attacks of hypertension and vomiting. A variety of agents were studied for their effects on the patient's signs and symptoms but none of these were demonstrated to have any therapeutic value.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Adam H de Havenon ◽  
Melissa Cortez ◽  
Cecilia Peterson ◽  
Fa Tuuhetaufa ◽  
Nils Petersen ◽  
...  

Background: Elevated blood pressure variability (BPV) in the days after acute stroke onset is associated with worse outcome. However, the mechanism of increased BPV remains unknown, but may be due to dysfunction of the autonomic nervous system, which can be measured by pupil response to a light stimulus. Methods: This is a retrospective study of 109 patients in a neurocritical care unit: 45 with acute ischemic stroke (AIS), 44 with intracerebral hemorrhage (ICH), and 20 with subarachnoid hemorrhage (SAH). The primary outcome is BPV, measured as standard deviation of SBP (SD), using all blood pressures from admission to 72 hours later. The primary predictors are pupillary light reflexes (PLR) from the same period, measured with a bedside pupilometer, the NPi-200. We used linear regression to evaluate the association between PLRs and BPV, and adjusted for patient age and gender. Results: The mean (SD) age was 60.7 (16.4) and 58.7% were male. The mean (SD) number of blood pressure and PLR measurements were 30.0 (9.0) and 10.4 (7.3). We found that parasympathetically mediated PLR measures were associated with BPV in AIS patients (Table 1), but no consistent pattern emerged in ICH or SAH patients (all p>0.05). The relationships between BPV and PLR for AIS patients were linear in nature (Figure 1), and were consistent with parasympathetic hypofunction in patients with the greatest BPV. Conclusions: Elevated BPV is associated with parasympathetic hypofunction, as measured by pupillary response to light, after acute ischemic, but not hemorrhagic, stroke. Further research is needed to better understand this relationship as it may represent a therapeutic target for BPV reduction.


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