The Role of the Peripheral Arterial Chemoreceptors in the Cardiovascular Responses of the Cat to Acute Systemic Hypoxia

Author(s):  
Gholam A. Dehghani ◽  
Robert S. Fitzgerald ◽  
Wayne Mitzner
Bioimpacts ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 55-61
Author(s):  
Nafiseh Mirzaei-Damabi ◽  
Bahar Rostami ◽  
Masoumeh Hatam

<span style="color: #1f497d;">Introduction: Parabrachial Kölliker-Fuse (KF) complex, located in dorsolateral part of the pons, is involved in the respiratory control, however, its role in the baroreflex and chemoreflex responses has not been established yet. This study was performed to test the contribution of the KF to chemoreflex and baroreflex and the effect of microinjection of a reversible synaptic blocker (Cocl2) into the KF in urethane anesthetized rats. <br /> <span style="color: #1f497d;">Methods: Activation of chemoreflex was induced by systemic hypoxia caused by N2 breathing for 30 seconds "hypoxic- hypoxia methods" and baroreflex was evoked by intravenous injection (i.v.) of phenylephrine (Phe, 20 µg /kg/0.05–0.1 mL). N2 induced generalized vasodilatation followed by tachycardia reflex and Phe evoked vasoconstriction followed by bradycardia.<br /> <span style="color: #1f497d;">Results: Microinjection of Cocl2 (5 mM/100 nL/side) produced no significant changes in the Phe-induced hypertension and bradycardia, whereas the cardiovascular effect of N2 was significantly attenuated by the injection of CoCl2 to the KF. <br /> <span style="color: #1f497d;">Conclusion: The KF played no significant role in the baroreflex, but could account for cardiovascular chemoreflex in urethane anesthetized rats.


2014 ◽  
Author(s):  
Molly Ann Metz ◽  
Heidi Kane ◽  
Thery Prok ◽  
Christena Cleveland ◽  
Nancy Collins

2021 ◽  
Vol 10 (7) ◽  
pp. 1413
Author(s):  
Judith Catella ◽  
Anne Long ◽  
Lucia Mazzolai

Some patients still require major amputation for lower extremity peripheral arterial disease treatment. The purpose of pre-operative amputation level selection is to determine the most distal amputation site with the highest healing probability without re-amputation. Transcutaneous oximetry (TcPO2) can detect viable tissue with the highest probability of healing. Several factors affect the accuracy of TcPO2; nevertheless, surgeons rely on TcPO2 values to determine the optimal amputation level. Background about the development of TcPO2, methods of measurement, consequences of lower limb amputation level, and the place of TcPO2 in the choice of the amputation level are reviewed herein. Most of the retrospective studies indicated that calf TcPO2 values greater than 40 mmHg were associated with a high percentage of successful wound healing after below-knee-amputation, whereas values lower than 20 mmHg indicated an increased risk of unsuccessful healing. However, a consensus on the precise cut-off value of TcPO2 necessary to assure healing is missing. Ways of improvement for TcPO2 performance applied to the optimization of the amputation-level are reported herein. Further prospective data are needed to better approach a TcPO2 value that will promise an acceptable risk of re-amputation. Standardized TcPO2 measurement is crucial to ensure quality of data.


2021 ◽  
Vol 22 (7) ◽  
pp. 3601
Author(s):  
Goren Saenz-Pipaon ◽  
Esther Martinez-Aguilar ◽  
Josune Orbe ◽  
Arantxa González Miqueo ◽  
Leopoldo Fernandez-Alonso ◽  
...  

Peripheral arterial disease (PAD) of the lower extremities is a chronic illness predominantly of atherosclerotic aetiology, associated to traditional cardiovascular (CV) risk factors. It is one of the most prevalent CV conditions worldwide in subjects >65 years, estimated to increase greatly with the aging of the population, becoming a severe socioeconomic problem in the future. The narrowing and thrombotic occlusion of the lower limb arteries impairs the walking function as the disease progresses, increasing the risk of CV events (myocardial infarction and stroke), amputation and death. Despite its poor prognosis, PAD patients are scarcely identified until the disease is advanced, highlighting the need for reliable biomarkers for PAD patient stratification, that might also contribute to define more personalized medical treatments. In this review, we will discuss the usefulness of inflammatory molecules, matrix metalloproteinases (MMPs), and cardiac damage markers, as well as novel components of the liquid biopsy, extracellular vesicles (EVs), and non-coding RNAs for lower limb PAD identification, stratification, and outcome assessment. We will also explore the potential of machine learning methods to build prediction models to refine PAD assessment. In this line, the usefulness of multimarker approaches to evaluate this complex multifactorial disease will be also discussed.


Author(s):  
Aditya K. Gupta ◽  
Madhulika A. Gupta ◽  
Richard C. Summerbell ◽  
Elizabeth A. Cooper ◽  
Nellie Konnikov ◽  
...  

2005 ◽  
Vol 96 (7) ◽  
pp. 996-1001 ◽  
Author(s):  
Annelies E. Aquarius ◽  
Johan Denollet ◽  
Jaap F. Hamming ◽  
Jolanda De Vries

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Rita Compagna ◽  
Bruno Amato ◽  
Salvatore Massa ◽  
Maurizio Amato ◽  
Raffaele Grande ◽  
...  

Critical limb ischemia (CLI) represents the most advanced stage of peripheral arterial obstructive disease (PAOD) with a severe obstruction of the arteries which markedly reduces blood flow to the extremities and has progressed to the point of severe rest pain and/or even tissue loss. Recent therapeutic strategies have focused on restoring this balance in favor of tissue survival using exogenous molecular and cellular agents to promote regeneration of the vasculature. These are based on stimulation of angiogenesis by extracellular and cellular components. This review article carries out a systematic analysis of the most recent scientific literature on the application of stem cells in patients with CLI. The results obtained from the detailed analysis of the recent literature data have confirmed the beneficial role of cell therapy in reducing the rate of major amputations in patients with CLI and improving their quality of life.


1980 ◽  
Vol 239 (1) ◽  
pp. R137-R142 ◽  
Author(s):  
J. Ciriello ◽  
F. R. Calaresu

To investigate the role of the paraventricular (PAH) and supraoptic (SON) nuclei in regulation of the cardiovascular system experiments were done in 26 cats anesthetized with alpha-chloralose, paralyzed, and artificially ventilated. Electrical stimulation of histologically verified sites in the region of the PAH and SON elicited increases in arterial pressure in bilaterally vagotomized animals and increases in heart rate both in spinal (C2) animals and in animals bilaterally vagotomized, In addition, stimulation of either the PAH or SON inhibited the reflex vagal bradycardia elicited by stimulation of the carotid sinus nerve (CSN) and bilateral lesions of these areas increased the magnitude of the response. On the other hand, stimulation and lesions of these hypothalamic regions did not alter the magnitude of the cardiovascular responses to stimulation of the aortic depressor nerve. These results demonstrate that stimulation of the PAH and SON elicit cardiovascular responses due to reciprocal changes in activity of the parasympathetic and sympathetic nervous systems and that these structures maintain a tonic inhibitory influence on the heart rate component of the CSN reflex.


1999 ◽  
Vol 276 (1) ◽  
pp. H63-H70 ◽  
Author(s):  
Shereeni J. Veerasingham ◽  
Frans H. H. Leenen

To examine the role of the ventral anteroventral third ventricle (vAV3V) in the hypertension induced by chronic subcutaneous ouabain and intracerebroventricular hypertonic saline, neurons in this area were destroyed by microinjection of an excitotoxin, ibotenic acid. Sham-operated or lesioned Wistar rats were administered ouabain (50 μg/day) or placebo for 3 wk from subcutaneously implanted controlled release pellets or artificial cerebrospinal fluid (CSF) or CSF containing 0.8 mol/l NaCl (5 μl/h) infused intracerebroventricularly for 2 wk. At the end of the experiment, mean arterial pressure (MAP) and heart rate at rest and in response to ganglionic blockade by intravenous hexamethonium (30 mg/kg) were assessed. In rats infused with hypertonic saline, responses to air jet stress were also assessed. Baseline MAP in sham-operated rats receiving intracerebroventricular hypertonic saline or subcutaneous ouabain was significantly higher than in control rats (115 ± 1 vs. 97 ± 3 and 121 ± 3 vs. 103 ± 3 mmHg, respectively). vAV3V lesions abolished the increase in MAP elicited by chronic infusion of hypertonic saline or administration of ouabain. Sham-operated rats treated with hypertonic saline or ouabain exhibited significantly enhanced decreases in MAP to hexamethonium, but lesioned rats did not. Rats infused with hypertonic saline demonstrated enhanced responses to air jet stress that were similar in sham-operated and lesioned rats. These results demonstrate that neurons in the vAV3V are essential for the hypertension induced by intracerebroventricular hypertonic saline and subcutaneous ouabain, possibly by increasing sympathetic tone. Cardiovascular responses to air jet stress appear not to be mediated by the vAV3V.


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