The aim of the present study was to explore the role of group II and III metabotropic glutamate receptors (mGluRs) in carotid body plasticity induced by chronic intermittent hypoxia (CIH) in rats. Sprague Dawley (SD) rats were treated with CIH in Oxycycler A84 hypoxic chamber for 4 weeks, and the tail artery blood pressure was measured at the end of model preparation. RT-qPCR was performed to examine the mRNA expression levels of mGluR2/3/8 in rat carotid body. Carotid sinus nerve activity was detected by ex vivo carotid sinus nerve discharge recording technique, and acute intermittent hypoxia (AIH) was administered to induce carotid body sensory long-term facilitation (sLTF), in order to observe the role of group II and group III mGluRs in carotid body plasticity induced by CIH. The results showed that: 1) After 4 weeks of CIH exposure, the blood pressure of rats increased significantly; 2) CIH down-regulated the mRNA levels of mGluR2/3, and up-regulated the mRNA level of mGluR8 in the carotid body; 3) AIH induced sLTF in carotid body of CIH group. In the CIH group, activation of group II mGluRs had no effect on sLTF of carotid body, while activation of group III mGluRs completely inhibited sLTF. These results suggest that CIH increases blood pressure in rats, and group III mGluRs play an inhibitory role in CIH-induced carotid body plasticity in rats.
Rats ; Animals ; Carotid Body/metabolism* ; Rats, Sprague-Dawley ; Hypoxia ; Receptors, Metabotropic Glutamate/metabolism* ; RNA, Messenger/metabolism*

The purpose of this study was to investigate the effect of glutamate and its ionotropic receptor agonists on the response to acute hypoxia in rat carotid body in vitro. Briefly, after SD rats were anesthetized and decapitated, the bilateral carotid bifurcations were rapidly isolated. Then bifurcation was placed into a recording chamber perfused with 95% O₂-5% CO₂ saturated Kreb's solution. The carotid body-sinus nerve complex was dissected, and the carotid sinus nerve discharge was recorded using a suction electrode. To detect the response of carotid body to acute hypoxia, the chamber was perfused with 5% O₂-5% CO₂-90% N₂ saturated Kreb's solution for a period of 100 s at an interval of 15 min. To observe the effect of glutamate, ionotropic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor agonist AMPA or N-methyl-D-aspartate (NMDA) receptor agonist NMDA on the response to acute hypoxia in rat carotid body, the chamber was perfused with 5% O₂-5% CO₂-90% N₂ saturated Kreb's solution containing the corresponding reagent. The results showed that glutamate (20 μmol/L), AMPA (5 μmol/L) or NMDA (10 μmol/L) inhibited the acute hypoxia-induced enhancement of carotid sinus nerve activity, and these inhibitory effects were dose-dependent. In summary, the activation of glutamate ionotropic receptors appears to exert an inhibitory effect on the response to acute hypoxia in carotid body of rats.
Rats ; Animals ; Glutamic Acid/pharmacology* ; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid/pharmacology* ; N-Methylaspartate/pharmacology* ; Carotid Body ; Rats, Sprague-Dawley ; Carbon Dioxide ; Receptors, N-Methyl-D-Aspartate ; Receptors, AMPA ; Hypoxia

The purpose of the present study was to explore the role of carotid body metabotropic glutamate receptor 1 (mGluR1) in chronic intermittent hypoxia (CIH)-induced carotid body plasticity. Sprague Dawley (SD) rats were exposed to CIH (6%-21% O₂, 4 min/cycle, 8 h/day) for 4 weeks. The blood pressure of rats was monitored non-invasively by tail-cuff method under consciousness. RT-qPCR was used to examine the mRNA expression level of mGluR1 in rat carotid body. Western blot was used to detect the protein expression level of mGluR1 in rat carotid body. The role of mGluR1 in CIH-induced carotid body sensory long-term facilitation (sLTF) was investigated by ex vivo carotid sinus nerve discharge recording, and the carotid body sLTF was evoked by a 10-episode of repetitive acute intermittent hypoxia (AIH: 1 min of 5% O₂ interspersed with 5 min of 95% O₂). The results showed that: 1) CIH increased the systolic blood pressure (P < 0.001), diastolic blood pressure (P < 0.005) and mean arterial blood pressure (P < 0.001) of rats; 2) CIH decreased the mRNA and protein levels of mGluR1 in the rat carotid body (P < 0.01); 3) 4 weeks of CIH induced carotid body sLTF significantly, exhibiting as an increasing baseline sensory activity during post-AIH, which was inhibited by application of an agonist of group I metabotropic glutamate receptors, (S)-3,5-dihydroxyphenylglycine (DHPG), during sLTF induction (P < 0.005). In summary, these results suggest that activation of mGluR1 inhibits CIH-induced carotid body plasticity in rats.
Rats ; Animals ; Carotid Body/metabolism* ; Rats, Sprague-Dawley ; Hypoxia ; Receptors, Metabotropic Glutamate/metabolism* ; RNA, Messenger/metabolism*

Objective To investigate the risk factors for patients using intraoperative vasopressor infusions during carotid body tumor(CBT)excision.Patients' mean arterial pressure(MAP)and heart rate(HR)fluctuations as well as their requirements for vasoactive agents during surgery were assessed. Methods The patients receiving CBT excision in Peking Union Medical College Hospital from May 1,2013 to July 31,2017 were included for a retrospective cohort study.The potential factors of intraoperative requirement for vasopressor infusions were investigated using univariate analysis and Logistic multivariate analysis.Furthermore,the relationships of Shamblin types of CBT with intraoperative MAP/HR fluctuations and requirements for vasoactive agents were analyzed. Results A total of 108 patients with 116 CBTs were included.Univariate analysis revealed that maximum tumor diameter >4 cm,intraoperative internal carotid artery injury,internal carotid artery reconstruction,malignant pathology,advanced Shamblin types(type Ⅱ and Ⅲ),estimated blood loss ≥400 ml,and operation duration >4 hours were associated with intraoperative requirements for vasopressor infusions.Logistic analysis showed that Shamblin type Ⅲ(OR=2.286,95% CI=1.324-14.926,P=0.016)and operation duration >4 hours(OR=3.874,95% CI=1.020-14.623,P=0.046)were risk factors for intraoperative requirements for vasopressor infusions during CBT surgery.In addition,Shamblin type Ⅲ was associated with intraoperative abnormal HR elevation and requirements for vasopressors.Conclusions Shamblin type Ⅲ and operation duration>4 hours are risk factors for intraoperative requirements of patients for using vasopressor infusions during CBT surgery.Shamblin type Ⅲ is associated with intraoperative abnormal HR elevation and requirements for vasopressors.
Carotid Body Tumor ; Humans ; Retrospective Studies ; Risk Factors ; Treatment Outcome ; Vascular Surgical Procedures

To investigate the value of head and neck CT angiography(CTA)in the evaluation of intraoperative hemorrhage of carotid body tumours. Head and neck CTA images of 36 patients with carotid body tumours confirmed by pathology were retrospectively analyzed.Patients were divided into two groups based on the intraoperative bleeding volume:<500 ml and≥500 ml groups.The patient's age,sex,Shamblin classification,size of the lesion,number of blood supply arteries,course of the disease,plain scan,and enhanced CT value between two groups were compared and analyzed.Logistics regression equation was established based on the CTA parameters with significant differences between the two intraoperative bleeding volume groups,and combined parameter was acquired.The receiver operating characteristic curve was established based on CTA single and combined parameters. The bleeding volume during the operation of carotid body tumors was significantly correlated with the age of patients(=0.019),the maximum diameter of tumours on axial images(=0.003),the maximum upper and lower diameters(=0.004),Shamblin classification(=0.012),and number of blood supply arteries(<0.001).The area under the receiver operating characteristic curve of the number of feeding arteries,the maximum diameter of axial images,maximum upper and lower diameters,Shamblin classification,and combined parameters were 0.865,0.781,0.806,0.766,and 0.927,respectively.When the optimal critical value was 0.408,the Youden index was 0.794,and the corresponding accuracy,sensitivity,and specificity were 0.919,0.909,and 0.923,respectively. Preoperative head and neck CTA can be used to evaluate the intraoperative blood loss.Combined parameters has the best diagnostic performance compared with single parameters.
Carotid Body Tumor ; diagnostic imaging ; Computed Tomography Angiography ; Head ; Humans ; Neck ; Retrospective Studies

BACKGROUND AND PURPOSE: We investigated whether the intracranial arterial calcification status reflects the overall cerebral atherosclerosis burden. METHODS: Patients with acute cerebral infarction who were admitted to a single university hospital stroke center and underwent brain computed tomography angiography (CTA) between May 2011 and December 2015 were included. We reviewed their demographic, clinical, and imaging data. Cerebral artery calcification was assessed from the cavernous portion of both internal carotid arteries, and patients were categorized into three groups according to the calcification status. The cerebral atherosclerosis score was calculated as the sum of the degree of stenosis of the major intracranial and extracranial arteries on brain CTA. RESULTS: In total, 1,161 patients were included (age=67±13 years, mean±standard deviation), of which 517 were female. Intracranial arterial calcification and atherosclerosis were detected in 921 patients. The cerebral atherosclerosis score tended to increase with the calcification status (no calcification=2.0±3.0, mild=3.8±3.8, severe=6.5±4.8; p < 0.001 in analysis of variance followed by the Bonferroni test). Multivariable logistic regression analysis including age, sex, vascular risk factors, body mass index, estimated glomerular filtration rate, high-sensitivity C-reactive protein, and calcification status showed that intracranial calcification was independently associated with an advanced cerebral atherosclerosis burden in a dose-dependent manner (compared to no calcification: odds ratio=2.0 and 95% confidence interval=1.1–3.4 for mild calcification, and odds ratio=4.7 and 95% confidence interval=2.7–8.3 for severe calcification). CONCLUSIONS: This study found that the calcification status of the cavernous portion of an internal carotid artery can reflect the overall cerebral atherosclerosis burden.
Angiography ; Arteries ; Atherosclerosis ; Body Mass Index ; Brain ; C-Reactive Protein ; Carotid Artery, Internal ; Cerebral Arteries ; Cerebral Infarction ; Constriction, Pathologic ; Female ; Glomerular Filtration Rate ; Humans ; Intracranial Arteriosclerosis* ; Logistic Models ; Risk Factors ; Stroke ; Vascular Calcification

Recent data suggest that subclinical atherosclerosis is more related to visceral adipose tissue distribution than to overall fat mass. Both perirenal fat and epicardial fat are visceral fat depots surrounding the kidneys and the myocardium, respectively, which can be easily assessed by ultrasound. Their clinical relevance in children is largely unknown. This review describes studies relating perirenal and epicardial fat to cardiovascular disease or carotid intima-media thickness (cIMT), a well-established surrogate for subclinical atherosclerosis, and discusses this in context with our own data from children. In adults, both perirenal and epicardial fat are useful biological markers of visceral obesity. The former has been related to hypertension in overweight subjects and with atherosclerosis in patients with human immunodeficiency virus. The latter was associated with several metabolic syndrome components and with calcification of the carotid artery. In healthy prepubertal children, both epicardial and perirenal fat thickness, rather than total body fat mass, were related to cIMT. Ultrasonography measures of perirenal and epicardial fat are related to atherosclerosis in adults and may be convenient tools for the assessment of cardiometabolic risk in children.
Adipose Tissue ; Adult ; Atherosclerosis ; Biomarkers ; Body Fat Distribution ; Cardiovascular Diseases ; Carotid Arteries ; Carotid Intima-Media Thickness ; Child ; HIV ; Humans ; Hypertension ; Intra-Abdominal Fat ; Kidney ; Myocardium ; Obesity, Abdominal ; Overweight ; Ultrasonography

PURPOSE: The purpose of this study was to investigate the effects of 12 weeks of combined exercise on vascular function-related inflammation, carotid intima-media thickness and fitness factors in obese middle-aged women with metabolic syndrome.METHODS: The subjects of this study were 40 middle-aged women in their 40s with metabolic syndrome but no specific disease. The exercise group performed aerobic exercise and resistance exercise five times a week for 12 weeks, and then measured body composition, blood pressure, vascular function-related inflammation factors, metabolic syndrome factors, carotid intima-media thickness, and physical factors.RESULTS: The exercise group showed a significant (p<0.05) reduction after exercise in all items related to body composition, systolic and diastolic blood pressure, and intima-media thickness of the right carotid and left carotid arteries. Exercise group showed a significant decrease (p<0.05) after exercise in interleukin-6, tumor necrosis factor-α, leptin, and all items of glucose metabolism-related variables. The exercise group showed a significant (p<0.05) increase after exercise physical efficiency index, grip strength, sit-ups, and sit & reach. After 12 weeks of exercise training, the reduction of intima-media thickness of the carotid artery was significantly (p<0.05) correlated with the improvement of body weight, systolic and diastolic blood pressure, grip and sit & reach, blood HbA1c, and triglyceride concentration.CONCLUSION: In conclusion, metabolic syndrome improved the body composition, blood glucose metabolism and lipid variables after 12 weeks of combined exercise program for obese middle-aged women. Significant improvement in blood pressure and carotid endometrial thickness, which is a function-related indicator, was confirmed.
Blood Glucose ; Blood Pressure ; Body Composition ; Body Weight ; Carotid Arteries ; Carotid Intima-Media Thickness ; Exercise ; Female ; Glucose ; Hand Strength ; Humans ; Inflammation ; Interleukin-6 ; Leptin ; Metabolism ; Necrosis ; Physical Fitness ; Triglycerides

BACKGROUND: Serum uric acid (UA) has been found to be associated with hypertension, obesity, dyslipidemia, and metabolic syndrome; however, its role as an independent risk factor of cardiovascular disease (CVD) is still controversial. There have been very few studies reporting an association between UA levels and carotid intima-media thickness (CIMT), especially in women.METHODS: The study included 245 subjects whose CIMT was evaluated between February 2016 and December 2017 at a health promotion center. We divided the population into two groups on the basis of menopausal status: premenopausal women (n=78) and postmenopausal women (n=167). We measured blood pressure, serum lipid profile, fasting blood glucose (FBG), and creatinine and UA levels. CIMT was measured using high-resolution B-mode ultrasonography.RESULTS: UA levels and CIMT were higher in postmenopausal women (P=0.029, P < 0.001). In premenopausal women, age (r=0.438), body mass index (r=0.373), UA (r=0.205), and FBG (r=0.336) were associated with CIMT, whereas in postmenopausal women, age (r=0.326), body mass index (r=0.167), UA (r=0.166), systolic blood pressure (r=0.200), and HDL-cholesterol (r=−0.140) were associated with CIMT. The UA level was independently associated with CIMT in premenopausal women (β=0.208, P=0.031), whereas age was the only factor independently associated with CIMT in postmenopausal women (β=0.253, P=0.002). Women in the highest tertile of uric acid level exhibited a higher CIMT than did those in the lowest tertile after age adjustment (P for trend < 0.001).CONCLUSION: UA may be an independent risk factor for CIMT, suggesting that UA is a risk factor for the early detection of CVD, especially in premenopausal women.
Blood Glucose ; Blood Pressure ; Body Mass Index ; Cardiovascular Diseases ; Carotid Intima-Media Thickness ; Creatinine ; Dyslipidemias ; Fasting ; Female ; Health Promotion ; Humans ; Hypertension ; Menopause ; Obesity ; Risk Factors ; Ultrasonography ; Uric Acid

Mortalities from cardiovascular disease in Korea have decreased markedly over the past three decades. The major cardiovascular and metabolic risk factors, however, remain prevalent, and their burden on health is large. The Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) planned a cohort study in order to identify novel risk factors and to develop evidence-based prevention strategies of cardiovascular and metabolic diseases. The CMERC deliberately designed two prospective cohorts, a community-based general population cohort (the CMERC cohort) and its sister cohort (a hospital-based high-risk patient cohort), covering a broad spectrum of cardiovascular and metabolic diseases. This paper describes the CMERC cohort study of community-dwelling adults aged 30 to 64 years. A total of 8097 adults completed baseline measurement between 2013 and 2018. Baseline measurements assessed socio-demographic factors, medical history, health-related behaviors, psychological health, social network and support, anthropometry, body composition, and resting blood pressure and comprised electrocardiography, carotid artery ultrasonography, fasting blood analysis, and urinalysis. Both active follow-up through an annual telephone survey and a 5-year on-site health examination survey and passive follow-up through secondary data linkage with national databases, such as national death records, have been applied. Researchers interested in collaborative research may contact the corresponding author.
Adult ; Anthropometry ; Blood Pressure ; Body Composition ; Cardiovascular Diseases ; Carotid Arteries ; Cohort Studies ; Death Certificates ; Electrocardiography ; Fasting ; Follow-Up Studies ; Humans ; Information Storage and Retrieval ; Korea ; Metabolic Diseases ; Mortality ; Prospective Studies ; Republic of Korea ; Risk Factors ; Siblings ; Telephone ; Ultrasonography ; Urinalysis