Microvascular research
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Microvascular research · Sep 2019
Imbalanced serum levels of Ang1, Ang2 and VEGF in systemic sclerosis: Integrated effects on microvascular reactivity.
Microangiopathy is a hallmark of systemic sclerosis (SSc). It is a progressive process from an early inflammatory and proangiogenic environment to insufficient microvascular repair with loss of microvessels. The exact underlying mechanisms remain ill-defined. Aim of the study was to investigate whether imbalanced angiopoietins/VEGF serum profile should be related in SSc to the altered microvascular reactivity characterized by aberrant angiogenesis and avascularity. ⋯ We found that serum levels of Ang1, Ang2 and VEGF are differentially expressed in SSc and altered Ang1/Ang2 profile might underlay the aberrant angiogenesis in SSc despite increase in VEGF. For the first time we identified that significant deficiency of Ang1 might be involved in early capillary enlargement, followed by collapse and lack of stable newly-formed vessels in VEGF-enriched environment, whereas Ang2 levels seem to increase later in disease progression and advanced microvascular damage ("Late" NVC pattern).
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Microvascular research · Sep 2019
Near-infrared spectroscopy detects transient decrements and recovery of microvascular responsiveness following prolonged forearm ischemia.
Impairments at the microvascular level might lead to more overt cardiovascular complications, therefore, being able to early detect microvascular dysfunction would be beneficial. Thus, the present study investigated whether near-infrared spectroscopy (NIRS) assessment of microvascular responsiveness (reoxygenation slope, %.s-1) would detect the detrimental effects on the forearm microvasculature following a period of arterial occlusion. Similarly, the effects of prolonged forearm ischemia on brachial artery function were also assessed by flow-mediated dilation (%FMD). ⋯ These findings show that NIRS-derived reoxygenation slope detects the transient detrimental effects of prolonged ischemia within the forearm microvasculature. Additionally, this study found that the reduction in forearm microvascular responsiveness might have contributed to the decreased brachial artery FMD responsiveness.