Cerebral vasoconstriction reactions and plasma levels of ETBR, ET-1, and eNOS in patients with chronic high altitude disease

Abstract

The aim of the present study was to examine cerebral vasoconstriction in patients with chronic high altitude disease [cerebrovascular reactivity (CVR)], and to evaluate differences in alterations of brain vascular contractile reactivity of chronic mountain sickness (CMS) patients and healthy controls. Alterations of endothelin (ET) and its receptor, as well as endothelial nitric oxide synthase (eNOS) levels in the plasma were examined to determine the cerebral reservation capacities in CMS patients. Transcranial Doppler ultrasound and carbon dioxide analysis methods were used to detect the CVR variances. At the same time, enzyme-linked immunosorbent assay approaches were utilized to detect the ET and ET B receptor and the eNOS levels in serum of the CMS patients and healthy controls. CVR and CVRI levels in CMS patients were lower than those of the healthy control subjects and the difference was statistically significant (P<0.05). By contrast, eNOS and ET-1 levels were not statistically significant for CMS and healthy controls (P>0.05). However, the ET receptor concentration level was higher in CMS than the healthy controls. Thus, ET-1 may not be a direct etiological variation but may play compensatory roles in CMS patients. The results of the study may provide scientific clues for the prevention and treatment of CMS with higher blood coagulation states of cerebral infarction in patients with chronic high altitude disease.

Cardiac-specific knockout and pharmacological inhibition of Endothelin receptor type B lead to cardiac resistance to extreme hypoxia

“…Given that EDNRB was first identified in human HA dwellers from Ethiopia known to be best adapted to HA [32], it is interesting to note a recent study showing that the level of EDNRB in serum was significantly higher in chronic mountain sickness (CMS) patients [33]. Furthermore, the cerebrovascular reactivity (CRV), i.e., the change in cerebral blood flow in response to a stimulus, was reportedly lower in these patients pretty much similar to patients with cardiac failure [34].…”

Association of Circulating Endothelial Nitric Oxide Synthase Levels with Phosphataemia in Patients on Haemodialysis

“…It is worth noting that our examined groups with type 2 DM and without DM as well as those with D and without D did not demonstrate differences in the examined clinical and demographic parameters, which could also have affected the lack of difference in the circulating eNOS levels. Many studies have revealed that patients on HD have many specific factors that impede eNOS activity, such as eNOS gene polymorphism [ 29 ], hyperparathyroidism [ 30 ], and oxidative stress [ 31 ]. The aforementioned uraemic eNOS inhibitors can dim and obliterate the effects of diabetes mellitus and dyslipidaemia on eNOS activity in HD patients.…”

Brain-aging related protein expression and imaging characteristics of mice exposed to chronic hypoxia at high altitude

“…In the case of acute hypobaric hypoxia, the body can ensure a supply of oxygen and energy to the brain by strengthening ventilation, accelerating the heart rate, increasing blood pressure, and changing the arterial blood gas balance. Acute hypoxia and hypoxia can stimulate the nervous and endocrine systems and may lead to the release of cytokines, such as endothelium-derived nitric oxide (NO), that cause systemic vasoconstriction, thereby increasing the CBF rate ( Wu et al, 2016 ). With gradual adaptation of the body to a high altitude environment, cerebrovascular reactivity, and vasomotor function are gradually restored and CBF slowly decreases to a level close to the normal range ( Lucas et al, 2011 ; Ainslie and Subudhi, 2014 ).…”