Objective: Inosine, a break-down product of adenosine, has been recently shown to exert inodilatory and anti-inflammatory properties. We investigated the effects of inosine on ischemia/reperfusion injury in a rat heart transplantation model.
Methods: Intraabdominal heterotopic transplantation was performed in Lewis rats. After 1h of ischemic preservation, reperfusion was started after application of either saline vehicle (control, n=12) or inosine (100 mg/kg, n=12). Coronary blood flow, left ventricular function, endothelium-dependent vasodilatation to acetylcholine and endothelium-independent vasodilatation to sodium nitroprusside, and high energy phosphate content were measured after 1 and 24h of reperfusion. In addition, the activation of the poly(ADP-ribose) polymerase was detected by immunhistology.
Results: After 1h, coronary blood flow (4.1+/-0.3 ml/(ming) vs 2.9+/-0.3 ml/(ming), p<0.05), left ventricular systolic pressure (102+/-9 mmHg vs 83+/-4 mmHg, p<0.05) and dP/dt (2765+/-609 mmHg/s vs 1740+/-116 mmHg/s, p<0.05) were significantly higher in the inosine group in comparison to control. Vasodilatatory response to sodium nitroprusside was similar in both groups. Acetylcholine resulted in a significantly higher increase in coronary blood flow in the inosine group (76+/-5% vs 48+/-9%, p<0.05). Energy charge potential was significantly higher in the inosine group (1.69+/-0.10 micromol/g vs 0.74+/-0.27 micromol/g, p<0.05). After 24h, there was no difference between the groups in basal coronary blood flow, left ventricular systolic pressure, dP/dt, and the response to sodium nitroprusside. However, acetylcholine led to a still significantly higher response in the inosine group (112+/-13% vs 88+/-7%, p<0.05). Immunhistologic stainings revealed activation of poly(ADP-ribose) polymerase in control animals which was abolished by inosine.
Conclusions: Thus, inosine improves myocardial and endothelial function during early reperfusion after heart transplantation with a persisting beneficial effect against reperfusion induced graft coronary endothelial dysfunction. The effects of inosine are mediated at least partly by modulation of the peroxynitrite-poly(ADP-ribose) polymerase pathway.
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http://dx.doi.org/10.1016/j.ejcts.2006.04.003 | DOI Listing |
Biochemistry (Mosc)
December 2024
Institute of Biochemistry and Biophysics, University of Tehran, Tehran, 13145-1384, Iran.
Inosine Monophosphate Dehydrogenase (IMPDH) catalyzes rate-limiting step of the reaction converting inosine monophosphate (IMP) to guanine nucleotides. IMPDH is up-regulated in the healthy proliferating cells and also in tumor cells to meet their elevated demand for guanine nucleotides. An exclusive regulatory mechanism for this enzyme is filamentation, through which IMPDH can resist allosteric inhibition by the end product, GTP.
View Article and Find Full Text PDFDig Liver Dis
January 2025
Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden; Department of Laboratory Medicine, Region Jönköping County, Jönköping, Sweden. Electronic address:
Background: Azathioprine (AZA) is part of the standard treatment for autoimmune hepatitis (AIH). The first step in the complex bioconversion of AZA to active metabolites is mediated by glutathione transferases (GSTs).
Aims: Elucidate the association between GSTM1 and GSTT1 copy number variation (CNV), genetic variation in GSTA2, GSTP1, and inosine-triphosphate-pyrophosphatase, and the response to AZA in AIH.
Curr Issues Mol Biol
December 2024
Department of Anesthesiology, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA 71103, USA.
Tacrolimus and mycophenolate are important immunosuppressive agents used to prevent organ rejection in post-transplant patients. While highly effective, their use is associated with significant toxicity, requiring careful management. Tacrolimus, a calcineurin inhibitor, is linked to nephrotoxicity, neurotoxicity, metabolic disturbances such as diabetes mellitus and dyslipidemia, and cardiovascular complications such as hypertension and arrhythmias.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Centre for Tuberculosis Research, Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, National Capital Region Biotech Science Cluster 3rd Milestone, Faridabad, Haryana 121001, India.
Itaconate, an abundant metabolite produced by macrophages upon interferon-γ stimulation, possesses both antibacterial and immunomodulatory properties. Despite its crucial role in immunity and antimicrobial control, its mechanism of action and dissimilation are poorly understood. Here, we demonstrate that infection of mice with increases itaconate levels in lung tissues.
View Article and Find Full Text PDFFront Cell Neurosci
January 2025
Laboratório de Neurodegeneração e Reparo - Departamento de Anatomia Patológica, Hospital Universitário Clementino Fraga Filho, HUCFF/UFRJ, Rio de Janeiro, Brazil.
Background: Following transection, nerve repair using the polylactic acid (PLA) conduit is an effective option. In addition, inosine treatment has shown potential to promote nerve regeneration. Therefore, this study aimed to investigate the regenerative potential of inosine after nerve transection and polylactic acid conduit repair.
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