Using passive tipping to a 45 degrees head-up position, an attempt was made to elicit reflex vasoconstriction in 13 non-distressed preterm infants and 27 infants with hyaline membrane disease, all between 26 and 38 weeks gestation. An increase in vascular tone associated with a significant reduction in peripheral blood-flow was found in 11 of the 13 non-distressed infants, while the same response was lacking in 23 of the 27 distressed infants. No infant demonstrated significant tachycardia with tilting, and the non-distressed infants failed to maintain their mean aortic blood-pressure during tilting. The results suggest that reflex control of vascular tone is present in non-distressed infants as early as 26 weeks gestation, but not in infats with hyaline membrane disease, possibly because of a maximal increase in vascular tone as a response to illness. This is indicated by the findings of significantly higher resting peripheral vascular resistance and lower peripheral blood-flow in infants with this diesease.
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http://dx.doi.org/10.1111/j.1469-8749.1979.tb01692.x | DOI Listing |
Br J Pharmacol
January 2025
Department of Medical Research, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan.
Background And Purpose: Perivascular adipose tissues (PVATs) play a critical role in modulating vascular homeostasis and protecting against cardiovascular dysfunction-mediated blood pressure dysregulation. We demonstrated that the activating transcription factor-3 (Atf3) gene in the PVAT is crucial for improving vascular wall tension abnormalities; however, its protective mechanism remains unclear. Herein, we aim to determine whether ATF3 regulates PVAT-derived relaxing factor (PVDRF) biosynthesis and if its secretion contributes to vasorelaxation.
View Article and Find Full Text PDFAnnual epidemics of influenza result in 3-5 million cases of severe illness and more than 600 000 deaths. Severe forms of influenza are usually characterized by vascular endothelial cells damage. Thus, influenza A viruses, including subtypes A(H1N1)pdm09, A(H3N2), as well as highly pathogenic avian influenza viruses, can infect the vascular endothelium, leading to activation and subsequent dysfunction of these cells.
View Article and Find Full Text PDFClin Auton Res
January 2025
Department of Cardiac Sciences, Libin Cardiovascular Institute, University of Calgary, GAC70 HRIC Building, 3280 Hospital Dr NW, Calgary, AB, T2N 4Z6, Canada.
Purpose: Long-coronavirus disease (long-COVID) is associated with initial orthostatic hypotension and postural orthostatic tachycardia syndrome. Whether altered autonomic tone underlies these abnormalities is unknown. We compared autonomic function between patients with long-COVID and healthy controls, and within patients with long-COVID with different orthostatic hemodynamic phenotypes.
View Article and Find Full Text PDFBr J Pharmacol
January 2025
Department of Pharmacology, University of Oxford, Oxford, UK.
Background And Purpose: TMEM16A chloride channels constitute a depolarising mechanism in arterial smooth muscle cells (SMCs) and contractile cerebral pericytes. TMEM16A pharmacology is incompletely defined. We elucidated the mode of action and selectivity of a recently identified positive allosteric modulator of TMEM16A (PAM_16A) and of a range of TMEM16A inhibitors.
View Article and Find Full Text PDFVascul Pharmacol
January 2025
Department of Clinical and Biological Sciences, University of Torino, Regione Gonzole 10, 10043 Orbassano, Italy. Electronic address:
The appropriate regulation of peripheral vascular tone is crucial for maintaining tissue perfusion. Myoendothelial junctions (MEJs), specialized connections between endothelial cells and vascular smooth muscle cells, are primarily located in peripheral resistance vessels. Therefore, these junctions, with their key membrane proteins, play a pivotal role in the physiological control of relaxation-contraction coupling in resistance arterioles, mainly mediated through endothelium-derived hyperpolarization (EDH).
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