Objective: Subarachnoid hemorrhage (SAH) causes cerebral ischemia and drastically worsens the clinical status at onset. However, the arterial flow is surprisingly well maintained on the cerebral surface. We investigated cortical microcirculatory changes in the super acute phase of SAH using two-photon laser scanning microscopy (TPLSM).
Methods: SAH was induced at the skull base in 10 mice using a prone endovascular perforation model. Before SAH, and 1, 2, 5, 10, 20, 30 and 60min after SAH, the cortical microcirculation was observed with TPLSM through a cranial window. Diameters of penetrating and precapillary arterioles were measured and red blood cell (RBC) velocities in precapillary arterioles were analyzed using a line-scan method after administration of Q-dot 655 nanocrystals.
Results: One minute after SAH, RBC velocity and flow in precapillary arterioles drastically decreased to <20% of the pre-SAH values, while penetrating and precapillary arterioles dilated significantly. Subsequently, the arterioles either dilated or constricted inconsistently for 60min with continual decreases in RBC velocity and flow in the arterioles, suggesting neurovascular dysfunction.
Conclusion: SAH caused sudden worsening of the cortical arteriolar velocity and flow at onset. The neurovascular unit cannot function sufficiently to maintain cortical microcirculatory flow in the super acute phase of SAH.
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http://dx.doi.org/10.1016/j.jns.2016.06.067 | DOI Listing |
Am J Obstet Gynecol
January 2025
Hasselt University, Faculty of Medicine and Life Sciences, Agoralaan, 3590 Diepenbeek, Belgium; Department of Obstetrics and Gynaecology, ZOL Genk, campus St. Jan, Schiepse Bos 6, 3600 Genk, Belgium.
Objective: To investigate the association between functional parameters of the microcirculation and the systemic cardiovascular system in a population of pregnant women at risk for gestational hypertension disorders.
Study Design: For this observational study, women at high cardiovascular risk according to maternal anthropometrics, obstetric and medical history, were recruited at random gestational age depending on time of referral to the outpatient clinic for high risk prenatal care at Ziekenhuis Oost Limburg, Genk Belgium. After birth, data of maternal and neonatal outcome were obtained from the hospital records: only women with normal pregnancy (n = 142) and with preeclampsia (n = 34) were included in this analysis.
Int J Mol Sci
December 2024
Institute of Physiology, University of Würzburg, 97070 Würzburg, Germany.
Nitric oxide-sensitive guanylyl cyclase (NO-GC) is a heterodimeric enzyme with an α- and a β-subunit. In its active form as an αβ-heterodimer, NO-GC produces cyclic guanosine-3',5'-monophophate (cGMP) to regulate vasodilation and proliferation of vascular smooth muscle cells (VSMCs). In contrast to VSMCs, only a few studies reported on the expression of the NO-GC αβ-heterodimer in human pericytes.
View Article and Find Full Text PDFbioRxiv
October 2024
Electrical Engineering and Computer Science Department, Florida Atlantic University, Boca Raton, FL, USA.
Autoregulation and neurogliavascular coupling are key mechanisms that modulate myogenic tone (MT) in vessels to regulate cerebral blood flow (CBF) during resting state and periods of increased neural activity, respectively. To determine relative contributions of distinct vascular zones across different cortical depths in CBF regulation, we developed a simplified yet detailed and computationally efficient model of the mouse cerebrovasculature. The model integrates multiple simplifications and generalizations regarding vascular morphology, the hierarchical organization of mural cells, and potentiation/inhibition of MT in vessels.
View Article and Find Full Text PDFDiagnostics (Basel)
July 2024
Department of Ophthalmology, Military Institute of Aviation Medicine, 01-755 Warsaw, Poland.
Purtscher retinopathy is a rare but severe sight-threatening eye condition that mostly occurs in middle-aged men after chest compression or head injury. In cases such as acute pancreatitis, connective tissue disorders, kidney failure or COVID-19 infection with similar ocular findings but no history of trauma, a diagnosis of Purtscher-like retinopathy is made. We present a case of a 72-year-old female with typical symptoms of Purtscher retinopathy in both eyes after a car crash accident.
View Article and Find Full Text PDFCirculation
August 2024
Institute of Physiology (Q.Z., N.Y., A.T., S.L., Q.L., N.H., C.L., L.E., M.M.K., W.M.K.), Charité-Universitätsmedizin, Berlin, Germany.
Background: Endothelial cell (EC) apoptosis and proliferation of apoptosis-resistant cells is a hallmark of pulmonary hypertension (PH). Yet, why some ECs die and others proliferate and how this contributes to vascular remodeling is unclear. We hypothesized that this differential response may: (1) relate to different EC subsets, namely pulmonary artery (PAECs) versus microvascular ECs (MVECs); (2) be attributable to autophagic activation in both EC subtypes; and (3) cause replacement of MVECs by PAECs with subsequent distal vessel muscularization.
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