The assumption that reversible inhibition of mitochondrial respiration by nitric oxide (NO.) represents inhibition of ATP synthesis is unproven. NO. could theoretically inhibit the oxygen consumption with continued ATP synthesis, by acting as an electron acceptor from cytochrome c or as a terminal electron acceptor in stead of oxygen. We report here that NO. does reversibly inhibit brain mitochondrial ATP synthesis with a time course similar to its inhibition of respiration. Whilst such inhibition was largely reversible, there appeared to be a small irreversible component which may theoretically be due to peroxynitrite formation, i.e. as a result of the reaction between NO. and superoxide, generated by the mitochondrial respiratory chain.
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http://dx.doi.org/10.1016/s0014-5793(99)00217-3 | DOI Listing |
Biochemistry
January 2025
Department of Chemistry and Biochemistry, San Francisco State University, 1600 Holloway Avenue, San Francisco, California 94132, United States.
Glutamine synthetase (GS) is a ubiquitous enzyme central to nitrogen metabolism, catalyzing the ATP-dependent formation of glutamine from glutamate and ammonia. Positioned at the intersection of nitrogen metabolism with carbon metabolism, the activity of GS is subject to sophisticated regulation. While the intricate regulatory pathways that govern GS were established long ago, recent work has demonstrated that homologues are controlled by multiple distinct regulatory patterns, such as the metabolite induced oligomeric state formation in archaeal GS by 2-oxoglutarate.
View Article and Find Full Text PDFBMC Complement Med Ther
January 2025
Department of Clinical Biochemistry, Afzalipour Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran.
Objective: This study aimed to investigate the synergistic effects of the chemotherapy drug Carfilzomib (CFZ) and Pistachio hull extract on the SK-BR3 breast cancer cell line.
Methods: In this experimental study, we evaluated the effect of Pistachio hull extract and CFZ as standalone treatments on cell viability using the MTT assay at 24- and 48-hours post-treatment. Following this, we conducted combination therapy analyses to assess the potential synergistic relationship between Pistachio hull extract and CFZ after 24- and 48-hours of treatment on both the SK-BR3 breast cancer cell line and the MCF10A normal cell line.
BMC Genomics
January 2025
College of Animal Science and Technology, Qingdao Agricultural University, Qingdao, 266109, China.
Background: The cryoinjury of semen during cryopreservation reduces sperm motility, constraining the application of artificial insemination (AI) in bovine reproduction. Some fertility markers, related to sperm motility before and after freezing have been identified. However, little is known about the biological mechanism through which freezing reduces sperm motility.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Horticulture, Faculty of Agriculture, University of Zanjan, Zanjan, Iran.
This study investigated the mechanisms employed by exogenous dopamine application in alleviating chilling injury in kiwifruits during storage at 1 °C for 120 days. Our results indicated that dopamine treatment at 150 µM alleviated chilling injury in kiwifruits during storage at 1 °C for 120 days. By 150 µM dopamine application, higher SUMO E3 ligase (SIZ1) and target of rapamycin (TOR) genes expression accompanied by lower poly(ADP-Ribose) polymerase 1 (PARP1) and sucrose non-fermenting 1-related kinase 1 (SnRK1) genes expression was associated with higher salicylic acid, ATP, NADPH and proline accumulation in kiwifruits during storage at 1 °C for 120 days.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Neuroscience, Center for Brain Immunology and Glia, University of Virginia School of Medicine, Charlottesville, VA, USA.
Microglia and the border-associated macrophages contribute to the modulation of cerebral blood flow, but the mechanisms have remained uncertain. Here, we show that microglia regulate the cerebral blood flow baseline and the responses to whisker stimulation or intra-cisternal magna injection of adenosine triphosphate, but not intra-cisternal magna injection of adenosine in mice model. Notably, microglia repopulation corrects these cerebral blood flow anomalies.
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