Adenosine Mediates Hypercapnic Response in the Rat Carotid Body via A2A and A2B Receptors

2018 ◽  
pp. 89-93 ◽  
Author(s):  
Joana F. Sacramento ◽  
Bernardete F. Melo ◽  
Sílvia V. Conde
Keyword(s):  
Carotid Body ◽  
Hypercapnic Response

scholarly journals Volatile Anaesthetic Depression of the Carotid Body Chemoreflex-Mediated Ventilatory Response to Hypoxia: Directions for Future Research

Scientifica ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
J. J. Pandit
Keyword(s):  
Quantitative Analysis ◽  
Carotid Body ◽  
Meta Analysis ◽  
Future Research ◽  
Inclusion Criteria ◽  
Molecular Processes ◽  
Similar Dose ◽  
Hypercapnic Response ◽  
Ventilatory Response To Hypoxia ◽  
Body Response

In assessing whether volatile anaesthetics directly depress the carotid body response to hypoxia it is necessary to combine in meta-analysis studies of when it is “functionally isolated” (e.g., recordings are made from its afferent nerve). Key articles were retrieved (full papers in English) and subjected to quantitative analysis to yield an aggregate estimate of effect. Results from articles that did not use such methodology were assessed separately from this quantitative approach, to see what could be learned also from a nonquantitative overview. Just 7 articles met the inclusion criteria for hypoxia and just 6 articles for hypercapnia. Within these articles, the anaesthetic (mean dose 0.75, standard deviation (SD) 0.40 minimum alveolar concentration, MAC) statistically significantly depressed carotid body hypoxic response by 24% (P=0.041), but a similar dose (mean 0.81 (0.42) MAC) did not affect the hypercapnic response. The articles not included in the quantitative analysis (31 articles), assessed qualitatively, also indicated that anaesthetics depress carotid body function. This conclusion helps direct future research on the anaesthetic effects on putative cellular/molecular processes that underlie the transduction of hypoxia in the carotid body.

Carotid body chemosensory function in prolonged normobaric hyperoxia in the cat

1987 ◽  
Vol 62 (5) ◽  
pp. 1924-1931 ◽  
Author(s):  
S. Lahiri ◽  
E. Mulligan ◽  
S. Andronikou ◽  
M. Shirahata ◽  
A. Mokashi
Keyword(s):  
Sea Level ◽  
Carotid Body ◽  
Chronic Exposure ◽  
Carotid Sinus ◽  
Sensory Nerves ◽  
Carotid Sinus Nerve ◽  
Normobaric Hyperoxia ◽  
Responses To Dopamine ◽  
Chemosensory Function ◽  
Hypercapnic Response

The effects of normobaric hyperoxia on carotid body chemosensory function in the cat were studied. The hypothesis was that carotid body chemosensory function would be affected by chronic exposure to 100% O2 at sea level. It was based on the assumptions that carotid body tissue is exposed to high PO2 because of its high blood flow and that its O2 chemosensing mechanism is sensitive to O2 radical-induced reactions. Twelve cats were exposed to 100% O2 for 60–67 h, and 10 control cats were maintained in room air at sea level. They were anesthetized with pentobarbital sodium (Nembutal), and chemosensory afferents from a cut carotid sinus nerve were isolated and identified. The responses of single or a few clearly identifiable chemoreceptor afferents to isocapnic hypoxia and hypercapnia during hyperoxia and to the bolus injections of cyanide, nicotine, and dopamine were studied. We found that chronic hyperoxia severely blunted or eliminated the O2-sensitive response of the carotid chemoreceptors while augmenting the hypercapnic response. The response to cyanide but not to nicotine and dopamine were attenuated. Thus the hypoxic and hypercapnic responses that normally interact were separable. The lack of the cyanide response was consistent with the lack of the hypoxic response, suggesting a possible shared mechanism of carotid chemoreceptor response. Qualitatively normal responses to dopamine and nicotine indicated that the respective receptors were relatively intact after chronic exposure to hyperoxia and that the sensory nerves themselves were not affected by the prolonged O2 exposure.

Effects of somatostatin, naloxone and prochlorperazine on the control of ventilation in man

1986 ◽  
Vol 70 (6) ◽  
pp. 547-554 ◽  
Author(s):  
D. L. Maxwell ◽  
K. B. Nolop ◽  
J. M. B. Hughes
Keyword(s):  
Carotid Body ◽  
Mode Of Action ◽  
Normal Subjects ◽  
Dopamine Antagonist ◽  
Opiate Antagonist ◽  
Hypoxic Response ◽  
Selective Effect ◽  
Ventilatory Responses ◽  
The Mean ◽  
Hypercapnic Response

1. In seven normal subjects the ventilatory responses to progressive isocapnic hypoxia and hyperoxic hypercapnia were measured during rebreathing. 2. During an infusion of somatostatin (10 nmol/mm) the mean hypoxic response decreased by 66% (control: − 1.6 sd 1.2 litres min−1 %−1Sao2: somatostatin: − 0.6 sd 0.7) but the mean hypercapnic response was unchanged (control: 2.0 sd 0.8 litre min−1 mmHg−1; somatostatin: 2.3 sd 1.2). There was no change in resting V˙O2 or V˙CO2 during somatostatin infusion. 3. The opiate antagonist, naloxone (0.1 mg/kg, intravenously), caused little change in either response (mean hypoxic response: − 1.7 sd 1.0 litre min−1 %−1Sao2; mean hypercapnic response: 2.4 sd 0.9 litre min−1 mmHg−1). 4. In five of the subjects the dopamine antagonist, prochlorperazine (10 mg, intravenously), increased the mean hypoxic response by 134% (control: − 1.9 sd 1.4 litres min−1 %−1Sao2; after prochlorperazine: − 3.8 sd 1.6; P < 0.05). The mean hypercapnic response after this drug was also increased (control: 2.1 sd 1.0 litre min−1 mmHg−1; after prochlorperazine: 3.1 sd 1.0) but this change did not achieve significance. 5. The selective effect of somatostatin on the hypoxic response, suggestive of an action on the carotid body, was not inhibited by prior injection of either naloxone or prochlorperazine, and its mode of action remains to be found.

Fine Structure of Carotid Body: Normal and Anoxic Cats

1967 ◽  
Vol 25 ◽  
pp. 150-151
Author(s):  
Fadhil Al-Lami ◽  
R.G. Murray
Keyword(s):  
Fine Structure ◽  
Adrenal Medulla ◽  
Carotid Body ◽  
Uranyl Acetate ◽  
Lead Citrate ◽  
Glomus Cells ◽  
Sustentacular Cells ◽  
Carotid Bodies

Although the fine structure of the carotid body has been described in several recent reports, uncertainties remain, and the morphological effects of anoxia on the carotid body cells of the cat have never been reported. We have, therefore, studied the fine structure of the carotid body both in normal and severely anoxic cats, and to test the specificity of the effects, have compared them with the effects on adrenal medulla, kidney, and liver of the same animals. Carotid bodies of 50 normal and 15 severely anoxic cats (9% oxygen in nitrogen) were studied. Glutaraldehyde followed by OsO4 fixations, Epon 812 embedding, and uranyl acetate and lead citrate staining, were the technics employed.We have called the two types of glomus cells enclosed and enclosing cells. They correspond to those previously designated as chemoreceptor and sustentacular cells respectively (1). The enclosed cells forming the vast majority, are irregular in shape with many processes and occasional peripheral densities (Fig. 1).

Onyx Embolization of Carotid Body Paragangliomas: An Adjunct to Safe and Effective Surgical Resection

2013 ◽  
Vol 74 (S 01) ◽  
Author(s):  
Felipe Albuquerque ◽  
Cameron McDougall ◽  
Robert Spetzler ◽  
Andrew Ducruet ◽  
Webster Crowley ◽  
...  
Keyword(s):  
Surgical Resection ◽  
Carotid Body

Presentation with Personality changes and Tinnitus to a Vascular Intervention: Rare case of Carotid Body Paraganglioma

2018 ◽  
pp. e000109
Author(s):  
Ahsan Zil-E-Ali ◽  
Zubair Ahmed ◽  
Amber Ehsan Faquih ◽  
Muhammad Ishaq ◽  
Muhammad Aadil
Keyword(s):  
Case Report ◽  
Carotid Body ◽  
Neuroendocrine Neoplasms ◽  
Vascular Surgeon ◽  
Vascular Intervention ◽  
Presenting Symptoms ◽  
Personality Changes ◽  
Tender Mass ◽  
Carotid Body Tumors ◽  
General Physical

Background: Carotid body paragangliomas are rare neuroendocrine neoplasms of chromaffin negative glomus cells. This case report explains an atypical case with unusual presentation and treatment. Case Report: A healthy smoker technician by profession was brought to the emergency room (ER) with coprolalia. The general physical exam did not reveal any information. His history revealed unilateral tinnitus and odynophagia leading to a consultation by the neurologist with head imaging. Acoustic neuroma was ruled out and the caregiver was asked to elaborate the events mentioned in the history and a psychiatric examination was done. The personality changes were evaluated by the psychiatrist that showed overlapping of delirium and depression. The patient was further examined by a vascular surgeon. After careful revisiting of the history, examination and indication of tender mass in the neck by the patient's vascular surgeon, the diagnosis of carotid body paraganglioma was made which was followed by surgical resection for treatment. Conclusion: Carotid Body Paragangliomas are very vascular structures and their manipulation in a surgery setting requires expertise. This case presented with personality changes and tinnitus, a very less likely event to occur in a carotid body tumor. The present care report, thus adds on to the literature of carotid body tumors and its presenting symptoms.

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