Endothelium-dependent relaxation is depressed in the femoral artery of dogs with heartworm, Dirofilaria immitis, infection. Moreover, in infected dogs, the mechanism of relaxation is different. Because D. immitis is located primarily in the pulmonary circulation, these findings suggested that D. immitis releases biologically active mediators that alter distal endothelium-dependent relaxation. We tested this hypothesis in vitro. Rings of rat aorta were exposed to D. immitis (alone, in 1,000 mol wt or 100 mol wt cutoff dialysis tubing, and bioassay with conditioned medium). D. immitis alone depressed relaxation to acetylcholine, carbachol, and A23187. Nitroglycerin relaxation was not affected. Depression of acetylcholine relaxation was seen with D. immitis alone, in 1,000 mol wt dialysis tubing, and bioassay with conditioned medium. However, acetylcholine relaxation with D. immitis in 100 mol wt dialysis tubing was not different from control. It appears that D. immitis releases a small, stable, biologically active factor that alters endothelium-dependent relaxation. Its exact nature is unknown. The study of endothelial cell behavior in filariasis and modulation of endothelial cell function by filarial factors may provide important clues in understanding the pathogenesis of parasitic diseases.
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http://dx.doi.org/10.1152/ajpheart.1990.259.2.H648 | DOI Listing |
Cell Commun Signal
January 2025
Beijing An Zhen Hospital, Capital Medical University, The Key Laboratory of Remodeling Cardiovascular Diseases, Ministry of Education; Collaborative Innovation Center for Cardiovascular Disorders, Beijing Institute of Heart Lung and Blood Vessel Disease, Beijing, 100029, China.
Background: The potential role of Klebsiella pneumoniae (K.pn) in hypertension development has been emphasized, although the specific mechanisms have not been well understood. Bacterial extracellular vesicles (BEVs) released by Gram-negative bacteria modulate host cell functions by delivering bacterial components to host cells.
View Article and Find Full Text PDFNutrients
December 2024
Institute of Medical Science, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada.
Background: There is compelling evidence of an inverse association between potassium intake and blood pressure (BP). A potential mechanism for this effect may be dietary potassium-mediated augmentation of endothelium-dependent relaxation. To date, studies have investigated potassium intake supplementation over several weeks in healthy volunteers with variable results on vascular function.
View Article and Find Full Text PDFJ Alzheimers Dis
January 2025
Division of Cardiothoracic Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, USA.
Biomedicines
December 2024
Department of Thermophysiology, Institute for Translational Medicine, Medical School, University of Pecs, 7624 Pecs, Hungary.
Hydrogen sulfide (HS) is a gasotransmitter that modulates vascular tone, causing either vasodilation or vasoconstriction depending on the vascular bed, species, and experimental conditions. The cold-sensitive transient receptor potential ankyrin-1 (TRPA1) channel mediates HS-induced effects; however, its contribution to the vasomotor responses of different arteries at different temperatures has remained unclear. Here, we aimed to fill this gap by comparing the effects of sodium sulfide (NaS), which is a fast-releasing HS donor, on the isolated carotid and tail skin arteries of rats and mice at cold and normal body temperature with wire myography.
View Article and Find Full Text PDFPharmacol Res
January 2025
Clinical, Experimental Surgery and Translational Research Center, Biomedical Research Foundation Academy of Athens, Greece; Faculty of Pharmacy, National and Kapodistrian University of Athens, Greece. Electronic address:
Metabolic syndrome (MetS) is a cluster of metabolic abnormalities that occur concurrently and increase the risk of cardiovascular disease. 3-mercaptopyruvate sulfurtransferase (MPST) is a cysteine-catabolizing enzyme that yields pyruvate and hydrogen sulfide (HS) and plays a central role in the regulation of energy homeostasis. Herein, we seek to investigate the role of MPST/HS in MetS and its cardiovascular consequences using a mouse model of the disease.
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