Post-prandial hyperlipidaemia results in systemic nitrosative stress and impaired cerebrovascular function in the aged

Post-prandial hyperlipidaemia (PPH) acutely impairs systemic vascular endothelial function, potentially attributable to a free radical-mediated reduction in vascular nitric oxide (NO) bioavailability (oxidative-nitrosative stress). However, it remains to be determined whether this extends to the cerebrovasculature. To examine this, 38 (19 young (≤35 years) and 19 aged (≥60 years)) healthy males were recruited. Cerebrovascular function (middle cerebral artery velocity, MCAv) and cerebrovascular reactivity to hypercapnea (CVRCO2Hyper) and hypocapnea (CVRCO2Hypo) were determined via trans-cranial Doppler ultrasound and capnography. Venous blood samples were obtained for the assessment of triglycerides (photometry), glucose (photometry), insulin (radioimmunoassay), ascorbate free radical (A•-, electron paramagnetic resonance spectroscopy) and nitrite (NO2 -, ozone-based chemiluminescence) in the fasted state prior to and 4 h following consumption of a standardized high-fat meal (1362 kcal; 130 g of fat). Circulating triglycerides, glucose and insulin increased in both groups following the high-fat meal (P < 0.05), with triglycerides increasing by 1.37 ± 1.09 mmol/l in the young and 1.54 ± 1.00 mmol/l in the aged (P < 0.05). This resulted in an increased systemic formation of free radicals in the young (P < 0.05) but not the aged (P > 0.05) and corresponding reduction in NO2 - in both groups (P < 0.05). While the meal had no effect on MCAv in either age group, CVRCO2Hyper was selectively impaired in the aged (P < 0.05). These findings indicate that PPH causes acute cerebrovascular dysfunction in the aged subsequent to systemic nitrosative stress

Methods and applications in vascular physiology : 2021

This Research Topic is a part of the Methods and Applications in Physiology series and aims at highlighting the latest experimental and computational methods in vascular physiology and their pharmacological, clinical and healthcare applications. The Research Topic includes methodological articles, describing either novel technical approaches or new applications of the conventional methods for measurement of vascular functions and parameters in health and pathological conditions

Erythropoietin : friend and foe!

Our knowledge of the erythropoietin (Epo) molecule has come a long way since Carnot and Deflandre's landmark observations, over a century agom, attributing the increase in red blood cells to a factor called 'hemopoietin'

Hemoglobin and hematocrit are not such good candidates to detect autologous blood doping

Letter to the editor: In a recent manuscript published in the International Journal of Hematology, Sallet et al. [1] reported absolute norms of variation established for a maximal 15 days period to distinguish autologous blood transfusion from normal modifications, using hematocrit (Ht), hemoglobin ([Hb]) and stimulation index (Off-hr) (calculated using the following equation [Hb] – 60√ reticulocytes in %) as markers. The thresholds the authors proposed are 6% for Ht, 4% for [Hb] and 20% for Off-hr. Although we grant this team for setting up new parameters to fight against blood doping, the application of the indirect detecting methodology for blood doping based on maximal variation of Ht, [Hb] and Off-hr requires additional considerations. We are concerned about the method used by the authors to establish the norms to tease out the “abnormal” variation

Commentary on Viewpoint: V̇o2peak is a useful and often necessary predictor of cardiorespiratory fitness

This article is one of a number of comments about V̇o2peak in the section "Commentaries on V̇o2peakViewpoint: V̇o2peak is an acceptable estimate of cardiorespiratory fitness but not V̇o2max"

Exercise, hypoxia and systemic oxygen extraction : a tale of two tips

Response to: Systemic oxygen extraction during exercise at high altitude, British Journal of Anaesthesia, Vol. 114, Issue 4 (2015), pp. 677-682, DOI: 10.1093/bja/aeu40

What role for hypercapnia in obstructive sleep apnea?

Letter to the editor: The question raised by Wang et al. (5) in their recent Viewpoint is important inasmuch as apneic events in obstructive sleep apnea (OSA) are associated with both hypoxia and hypercapnia

Reduced serum selenium : a molecular risk factor for abdominal aortic aneurismal disease?

Aim: Abdominal aortic aneurysm (AAA) is a common condition present in approximately 4% of the male UK males over 65. Studies show levels of several heavy metals including Selenium (Se) may affect both aneurysm formation and growth. The aim of this study was to look at Se levels relating to AAA size. Methods: Males undergoing AAA screening underwent a health and medication questionnaire prior to Duplex ultrasonography (USS) to assess AAA size. Measurement of serum selenium concentration was performed. Data was analysed using a one-way analysis of variance and post hoc Bonferonni- corrected independent samples t-tests. Results: 73 patients were allocated to 3 groups. The control group: AAA (<3 cm) presented with a Selenium concentration of 0.93 μmol/L, (mean) +/-0.15(SD) By comparison Selenium concentrations were lower in patients with AAA 3-4.4 cm 0.78 μmol/L (=/-0.16) (p = <0.05), and AAA 4.5-5.4 cm 0.78umol/L (+/-0.19) (p= <0.05). An inverse relationship was observed between serum Selenium concentration and AAA diameter (r = -0.56, P = <0.05, pooled data). Conclusion: Our findings support the concept that depressed serum Selenium may prove a molecular biomarker with the potential to “track” patients potentially vulnerable to aneurismal disease