- Severe bradycardia caused by the deviation of the laryngeal mask airway Supreme: A case report. [Journal Article]
- MMedicine (Baltimore) 2019; 98(24):e15904
- CONCLUSIONS: The position of LMA Supreme should be confirmed throughout the surgery especially for the ones who has changed the position and the head was covered by surgical drapes.
- Selective denervation of the aortic and carotid baroreceptors in rats. [Journal Article]
- EPExp Physiol 2019 Jun 04
- What is the central question of this study? The traditional surgical approach for sinoaortic denervation in rats leads to simultaneous carotid baroreceptor and chemoreceptor deactivation, not allowin…
What is the central question of this study? The traditional surgical approach for sinoaortic denervation in rats leads to simultaneous carotid baroreceptor and chemoreceptor deactivation, not allowing their individual study in different situations. What is the main finding and its importance? We have described a new surgical approach capable to selectively denervate the arterial (aortic and carotid) baroreceptors, keeping the carotid bodies - chemoreceptors - intact. It is understood that this technique may be a useful tool for investigating the relative role of the baro- and chemoreceptors, under several physiological and pathophysiological conditions.
- Serotonin-Mediated Cardiac Analgesia via Ah-Type Baroreceptor Activation Contributes to Silent Angina and Asymptomatic Infarction. [Journal Article]
- NNeuroscience 2019 May 31; 411:150-163
- Silent angina is a critical phenomenon in the clinic and is more commonly associated with women patients suffering from myocardial ischemia. Its underlying cause remains mysterious in medicine. With …
Silent angina is a critical phenomenon in the clinic and is more commonly associated with women patients suffering from myocardial ischemia. Its underlying cause remains mysterious in medicine. With our recent discovery of female-specific Ah-type baroreceptor neurons (BRNs), we hypothesize that cardiac analgesia is due to the direct activation of Ah-type BRNs by elevated levels of circulating serotonin (5-HT) myocardial infarction (MI) patients. Electromyography and the tail-flick reflex were assessed in control and MI-model rats to evaluate 5-HT-mediated BP regulation as well as peripheral and cardiac nociception. 5-HT or a 5-HT receptor agonist was microinjected into the nodose ganglion to confirm the involvement of the afferent pathway of the baroreflex arc. An inward current was observed in identified BRNs by applying a whole-cell patch-clamp technique in conjunction with qRT-PCR to verify the afferent-specific action of 5-HT and the expression of 5-HT receptors. Although the tail-flick reflex and mean arterial pressure were dramatically reduced in female MI rats with elevated serum 5-HT, intrapericardial capsaicin-evoked muscular discharges were significantly inhibited in comparing with those of males, which were mimicked by microinjection of 5-HT or SR57227A into the nodose. Ah-type BRNs displayed robust inward currents at lower concentrations of 5-HT than the C-type or the A-type, with significantly increased expression and cellular distribution of 5-HT3AR but not 5-HT3BR compared to the A- and C-types. Activation of 5-HT3AR in Ah-type BRNs by 5-HT contributes significantly to cardiac analgesia, which may suggest the pathogenic condition that silent angina occurs mainly in female patients.
- The Effect of Stroke Subtypes on Baroreceptor Sensitivity, a Predict for Acute Stroke Outcome. [Journal Article]
- BRBiomed Res Int 2019; 2019:7614828
- CONCLUSIONS: Beside NIHSS score on admission, BRS is a potential prognostic factor of 1-month outcomes in patients with AIS. Patients with large hemisphere infarction or brainstem infarction have more blunting BRS than do those with lacunar infarction, which provides some insight into which patients may be expected to have a poor outcome.
- AT1 Receptor Mediated Hypertensive Response to Ang II in the Nucleus Tractus Solitarii of Normotensive Rats Involves NO Dependent Local GABA Release. [Journal Article]
- FPFront Pharmacol 2019; 10:460
- CONCLUSIONS: Our results suggest that the AT1R mediated hypertensive response to angiotensin II within the NTS in normotensive rats is GABA and NO dependent. Nitric oxide produced within the NTS tonically potentiates local GABA and glutamate release.
- Corticospinal excitability for flexor carpi radialis decreases with baroreceptor unloading during intentional co-contraction with opposing forearm muscles. [Journal Article]
- EBExp Brain Res 2019 May 25
- Concurrent activation of antagonistic muscles (co-contraction) is used for stiffening a joint, whereas its neural control under hemodynamic stress (e.g., posture change, high gravity, and hemorrhage)…
Concurrent activation of antagonistic muscles (co-contraction) is used for stiffening a joint, whereas its neural control under hemodynamic stress (e.g., posture change, high gravity, and hemorrhage) is unknown. Corticospinal excitability during co-contraction may be altered with baroreceptor unloading due to potential modulations in spinal and/or inhibitory pathways (e.g., disynaptic group I inhibition and GABA-mediated intracortical inhibition). The purpose of this study was to understand the effect of baroreceptor unloading on corticospinal excitability during co-contraction in humans. Motor evoked potential and cortical silent period in a wrist flexor muscle were examined using transcranial magnetic stimulation in two groups of healthy young adults. All subjects performed isometric contraction of the wrist flexors (flexion) and co-contraction of the wrist flexors and extensors (co-contraction). Spinal disynaptic inhibition was also assessed with the ratio of H-reflex responses to unconditioned and conditioned electrical stimulations of the peripheral nerves for the muscles. In one of the groups, baroreflex unloading was induced by applying lower body negative pressure. There was no significant effect of baroreflex unloading on cortical silent period or H-reflex measure of disynaptic inhibition. With baroreflex unloading, motor evoked potential area in the flexor carpi radialis was decreased during co-contraction but not during flexion. The results indicated that baroreceptor unloading decreases corticospinal excitability during co-contraction of antagonistic muscles, apparently by influencing neural pathways that were not probed with cortical silent period or spinal disynaptic inhibition.
- Carotid baroreceptor stimulation in obese rats affects white and brown adipose tissues differently in metabolic protection. [Journal Article]
- JLJ Lipid Res 2019 May 24
- Sympathetic nervous system (SNS) regulates the functions of white adipose tissue (WAT) and brown adipose tissue (BAT) tightly. Carotid baroreceptor stimulation (CBS) efficiently inhibits SNS activati…
Sympathetic nervous system (SNS) regulates the functions of white adipose tissue (WAT) and brown adipose tissue (BAT) tightly. Carotid baroreceptor stimulation (CBS) efficiently inhibits SNS activation. We hypothesized that CBS would protect against obesity. We administered CBS to obese rats and measured sympathetic and AMP-activated protein kinase (AMPK)/peroxisome proliferator activated receptor (PPAR) pathway responses as well as changes in perirenal white adipose tissue (PWAT), epididymal white adipose tissue (EWAT), and interscapular brown adipose tissue (IBAT). CBS alleviated obesity related metabolic changes, improving insulin resistance; reducing adipocyte hypertrophy, body weight, and adipose tissue weights; and decreasing norepinephrine (NE) but increasing acetylcholine (ACH) in plasma, PWAT, EWAT, and IBAT. CBS also downregulated fatty acid translocase (CD36), fat acid transport protein (FATP), phosphorylated and total hormone sensitive lipase, phosphorylated and total protein kinase A, and PPARɣ in obese rats. Simultaneously, CBS upregulated phosphorylated adipose triglyceride lipase, phosphorylated and total AMPK, and PPARα in PWAT, EWAT, and IBAT. However, BAT and WAT responses differed; although many responses were more sensitive in IBAT, responses of CD36, FATP, and PPARɣ were more sensitive in PWAT and EWAT. Overall, CBS decreased chronically activated SNS and ameliorated obesity related metabolic disorders by regulating the AMPK/PPARα/ɣ pathway.
- Anaphylaxis stimulates afferent vagal nerve activity and efferent sympathetic nerve activity in the stomach of anesthetized rats. [Journal Article]
- AJAm J Physiol Regul Integr Comp Physiol 2019 May 22
- Systemic anaphylaxis is a life-threatening and allergic reaction that affects various organs. We previously reported that in the stomach, gastric vasoconstriction occurring at the late phase (15-55 m…
Systemic anaphylaxis is a life-threatening and allergic reaction that affects various organs. We previously reported that in the stomach, gastric vasoconstriction occurring at the late phase (15-55 min after injection of ovalbumin antigen) was observed in anesthetized rats sensitized with ovalbumin. In addition, anaphylaxis enhances gastric motility and delays emptying. However, the role of extrinsic autonomic nervous system on antigen-induced gastric alterations was not known. Thus, using the same rat anaphylaxis model, we aimed to determine the changes in the efferent and afferent autonomic nerve activities in the stomach during anaphylactic hypotension. The findings showed that injection of ovalbumin antigen cause a substantial systemic hypotension in all sensitized rats. The efferent gastric sympathetic nerve activity (ef-GSNA), but not the efferent vagal nerve activity, increased only at the early phase (1-10 min after injection of ovalbumin antigen) and showed baroreceptor reflex, as evidenced by a stimulatory response to sodium nitroprusside-induced hypotension. In general, excitation of ef-GSNA could induce pylorus sphincter contraction and gastric vasoconstriction. In the present study, we found that sympathectomy attenuated anaphylaxis-induced decease in gastric flux, but not increase in gastric vascular resistance. Thus, the increase in ef-GSNA may cause anaphylactic pylorus sphincter contraction, but not anaphylactic gastric vasoconstriction. On the other hand, the afferent gastric vagal nerve activity, but not the afferent sympathetic nerve activity, increased during the early phase of anaphylactic hypotension. However, vagotomy produced no effects on the anaphylactic gastric dysfunction. In conclusion, the gastric sympathetic nerves partly modulate stomach function during systemic anaphylaxis.
- Association Between Systemic Inflammation, Carotid Arteriosclerosis, and Autonomic Dysfunction. [Journal Article]
- TSTransl Stroke Res 2019 May 16
- Systemic inflammation is associated with arteriosclerotic disease progression and worse stroke outcome in patients with carotid arteriosclerotic disease. We hypothesize that systemic inflammation is …
Systemic inflammation is associated with arteriosclerotic disease progression and worse stroke outcome in patients with carotid arteriosclerotic disease. We hypothesize that systemic inflammation is mediated by impaired carotid baroreceptor and chemoreceptor function induced by carotid arteriosclerosis rather than by the generalized inflammatory arteriosclerotic process.Heart rate variability (HRV), serum levels of inflammatory markers, demographic and life style factors, and concomitant diseases with potential impact on systemic inflammation were determined in 105 patients with asymptomatic carotid stenosis of varying degree. Multivariate linear regression analyses were performed to ascertain independent determinants of carotid stenosis severity, autonomic function, and inflammation.Systemic inflammation (C-reactive protein, beta = .255; P = .014), age (beta = .232; P < .008), and arterial hypertension (beta = .206; P = .032) were associated with carotid stenosis severity. Only carotid stenosis severity and not generalized arteriosclerotic disease, concomitant diseases (arterial hypertension, diabetes mellitus, dyslipidemia, hypothyroidism), life style factors (smoking, obesity), or age was associated with a reduction in vagal tone (HRV HF band power beta = - .193; P < 0.049). Systemic inflammation was related to a reduction in vagal tone (HRV HF band power, beta = - .214; P = .031), and not to generalized arteriosclerotic disease, concomitant diseases (arterial hypertension, diabetes mellitus, dyslipidemia), life style factors (smoking, obesity), and age.In conclusion, systemic inflammation is associated with carotid rather than with generalized arteriosclerotic disease. The association between systemic inflammation and carotid arteriosclerosis is mediated by a reduction in vagal tone which indicates a major role of carotid arteriosclerosis-mediated autonomic dysfunction in the pathogenesis of systemic inflammation in arteriosclerotic disease.
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- Habitual Cigarette Smoking Raises Pressor Responses to Spontaneous Bursts of Muscle Sympathetic Nerve Activity. [Journal Article]
- AJAm J Physiol Regul Integr Comp Physiol 2019 May 15
- Smoking is a risk factor for cardiovascular diseases. Prior reports showed a transient increase in blood pressure following a spontaneous burst of muscle sympathetic nerve activity (MSNA). We hypothe…
Smoking is a risk factor for cardiovascular diseases. Prior reports showed a transient increase in blood pressure following a spontaneous burst of muscle sympathetic nerve activity (MSNA). We hypothesized that this pressor response would be accentuated in smokers. Using signal averaging techniques, we examined the blood pressure (Finometer) response to MSNA in 18 otherwise healthy smokers and 42 healthy non-smokers during resting conditions. The sensitivities of baroreflex control of MSNA and heart rate were also assessed. The mean resting MSNA, heart rate and mean arterial pressure in smokers were higher than values seen in non-smokers. The mean arterial pressure increase following a burst of MSNA was significantly greater in smokers than that in non-smokers (Δ3.4 ± 0.3 vs. Δ1.6 ± 0.1 mmHg, P < 0.001). The baroreflex sensitivity of burst incidence, burst area or total activity were not different between two groups. However, cardiac baroreflex sensitivity was lower in smokers than in non-smokers (14.6 ± 1.7 vs. 24.6 ± 1.5 ms/mmHg, P < 0.001). Moreover, the mean arterial pressure increase following a burst was negatively correlated with the cardiac baroreflex sensitivity. These observations suggest that habitual smoking in otherwise healthy individuals raises the blood pressure increase following spontaneous MSNA, and the attenuated cardiac baroreflex sensitivity in the smokers contributed to this observation. We speculate that the accentuated pressor increase to the spontaneous MSNA may contribute to the elevated resting blood pressure in the smokers.