Cardiomyopathy is a common, life-threatening, but poorly understood complication of HIV infection. The purpose of the present study is to study the effects of an HIV surface envelope protein, glycoprotein 120 (gp120), on cell contraction and L-type Ca(2+) current in rabbit ventricular myocytes. Rabbit ventricular cells were isolated by an enzyme dissociation method. Cell contractions were induced by electric field stimulation. Whole cell L-type Ca(2+) channel currents were measured by the whole cell voltage-clamp technique. We found that perfusion with solution containing gp120 (0.1 microg/ml) derived from HIV-1(SF2) significantly inhibited field-stimulated contractions and L-type Ca(2+) current in rabbit ventricular myocytes as compared with perfusion with buffer alone. These results suggest that HIV-1 gp120 may directly contribute to cardiac dysfunction as seen in many HIV patients.
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http://dx.doi.org/10.1089/08892220260139512 | DOI Listing |
Free Radic Res
January 2025
Department of Human and Animal Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia.
Reactive oxygen species (ROS) produced by NADPH oxidase promote contraction of peripheral arteries, which is especially pronounced in early postnatal period in comparison to adulthood, but the mechanisms of such vasomotor influence are poorly understood. We tested the hypothesis that Rho-kinase and protein kinase C (PKC) mediate procontractile influence of NADPH oxidase derived ROS in peripheral artery of early postnatal rats. In addition, we evaluated the involvement Src-kinase and L-type voltage-gated Ca channels (LTCC) into procontractile influence of ROS, produced by NADPH oxidase, because of their known interplay with Rho-kinase and PKC pathways.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2025
Department of Physiology and Membrane Biology, University of California Davis, Davis, CA 95616.
The L-type Ca channel (Ca1.2) is essential for cardiac excitation-contraction coupling. To contribute to the inward Ca flux that drives Ca-induced-Ca-release, Ca1.
View Article and Find Full Text PDFJ Cardiovasc Pharmacol
January 2025
Division of Clinical Physiology, Department of Cardiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
Positive inotropic responses upon administration of milrinone, an inhibitor of the phosphodiesterase enzyme (PDE), involve a well-pronounced positive chronotropic effect. Here we tested whether milrinone evokes this chronotropic response solely by PDE inhibition or by a concerted action that involve additional pharmacological targets. Milrinone stimulated increases in heart rate were studied in right atrial preparations of guinea pig in the presence or absence of inhibitors of putative ancillary molecular pathways or ion channels: i.
View Article and Find Full Text PDFCardiovasc Toxicol
January 2025
Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, No. 250, Wuxing St., Taipei, 11031, Taiwan.
Ventricular arrhythmias (VAs) are major causes of sudden cardiac death in chronic kidney disease (CKD) patients. Indoxyl sulfate (IS) is one common uremic toxin found in CKD patients. This study investigated whether IS could induce VAs via increasing right ventricular outflow tract (RVOT) arrhythmogenesis.
View Article and Find Full Text PDFbioRxiv
January 2025
Oregon Hearing Research Center and Vollum Institute, Oregon Health & Science University, Portland, Oregon, 97239.
Exposure to loud and/or prolonged noise damages cochlear hair cells and triggers downstream changes in synaptic and electrical activity in multiple brain regions, resulting in hearing loss and altered speech comprehension. It remains unclear however whether or not noise exposure also compromises the cochlear efferent system, a feedback pathway in the brain that fine-tunes hearing sensitivity in the cochlea. We examined the effects of noise-induced hearing loss on the spontaneous action potential (AP) firing pattern in mouse lateral olivocochlear (LOC) neurons.
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