Background: The goal of this study was to determine the effects of ACE inhibition (ACEI) alone, AT1 angiotensin (Ang) II receptor blockade alone, and combined ACEI and AT1 Ang II receptor blockade on LV function, systemic hemodynamics, and neurohormonal system activity in a model of congestive heart failure (CHF).
Methods And Results: Pigs were randomly assigned to each of 5 groups: (1) rapid atrial pacing (240 bpm) for 3 weeks (n=9), (2) ACEI (benazeprilat, 0.187 mg x kg(-1) x d(-1)) and rapid pacing (n=9), (3) AT1 Ang II receptor blockade (valsartan, 3 mg x kg(-1) x d(-1)) and rapid pacing (n=9), (4) ACEI and AT1 Ang II receptor blockade (benazeprilat/valsartan, 0.05/3 mg x kg(-1) d(-1)) and rapid pacing (n=9), and (5) sham controls (n=10). In the pacing group, LV fractional shortening (LVFS) fell (13.4+/-1.4% versus 39.1+/-1.0%) and end-diastolic dimension (LVEDD) increased (5.61+/-0.11 versus 3.45+/-0.07 cm) compared with control (P<.05). With AT1 Ang II blockade and rapid pacing, LVEDD and LVFS were unchanged from pacing-only values. ACEI reduced LVEDD (4.95+/-0.11 cm) and increased LVFS (20.9+/-1.9%) from pacing-only values (P<.05). ACEI and AT1 Ang II blockade reduced LVEDD (4.68+/-0.07 cm) and increased LVFS (25.2+/-0.9%) from pacing only (P<.05). Plasma norepinephrine and endothelin increased by more than fivefold with chronic pacing and remained elevated with AT1 Ang II blockade. Plasma norepinephrine was reduced from pacing-only values by more than twofold in the ACEI group and the combination group. ACEI and AT1 Ang II receptor blockade reduced plasma endothelin levels by >50% from rapid-pacing values.
Conclusions: These findings suggest that the effects of ACEI in the setting of CHF are not solely due to modulation of Ang II levels but rather to alternative enzymatic pathways and that combined ACEI and AT1 Ang II receptor blockade may provide unique benefits for LV pump function and neurohormonal systems in the setting of CHF.
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http://dx.doi.org/10.1161/01.cir.96.7.2385 | DOI Listing |
Pathogens
December 2024
Immunology and Infectious Diseases Program, Division of BioMedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL A1B 3V6, Canada.
Natural killer (NK) and CD8 T cell function is compromised in human immunodeficiency virus type 1 (HIV-1) infection by increased expression of inhibitory receptors such as TIGIT (T cell immunoreceptor with Ig and ITIM domains). Blocking inhibitory receptors or their ligands with monoclonal antibodies (mAb) has potential to improve antiviral immunity in general and facilitate HIV eradication strategies. We assessed the impact of TIGIT engagement and blockade on cytotoxicity, degranulation, and interferon-gamma (IFN-γ) production by CD8 T cells from persons living with HIV (PLWH).
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Molecular Genetics, The Weizmann Institute of Science, Rehovot 7610001, Israel.
Interleukin-18 (IL-18) serves a dual function in the immune system, acting as a "double-edged sword" cytokine. Depending on the microenvironment and timing, IL-18 can either drive harmful inflammation or restore immune homeostasis. Pathologies characterized by elevated IL-18, recently proposed to be termed IL-18opathies, highlight the therapeutic potential for IL-18 blockade.
View Article and Find Full Text PDFMedicina (Kaunas)
December 2024
Otolaryngology Head and Neck Surgery, Department Medical and Surgical Sciences, University "Magna Graecia" of Catanzaro, 88100 Catanzaro, Italy.
: Chronic rhinosinusitis (CRS) is a complex inflammatory condition of the nasal passages that severely impairs quality of life. Type 2 CRS is characterized by eosinophilic inflammation, driven by cytokines like IL-4, IL-5, and IL-13. These cytokines are key to CRS pathogenesis and contribute to a heavy disease burden, especially with comorbidities.
View Article and Find Full Text PDFBiomedicines
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 PDFAntioxidants (Basel)
December 2024
Otto Loewi Research Center for Vascular Biology, Immunology and Inflammation, Division of Pharmacology, Medical University of Graz, 8010 Graz, Austria.
Endothelial dysfunction is a hallmark of several pathological conditions, including cancer, cardiovascular disease and inflammatory disorders. In these conditions, perturbed TCA cycle and subsequent succinate accumulation have been reported. The role of succinate as a regulator of immunological responses and inflammation is increasingly being recognized.
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