We have previously shown that exposure to 100% oxygen for 2 h results in a two-fold decrease in the brain glutamine synthetase activity of neonatal rats. The present study examines whether this decrement in enzyme activity leads to a global accumulation of glutamate, an excitotoxin which is a substrate for this enzyme. Despite a demonstrable decrement in whole brain glutamine synthetase activity, whole brain glutamate content is unaltered in animals exposed to 100% oxygen for 2 h. Furthermore, despite a persistent two-fold decrement in glutamine synthetase activity in animals exposed to 100% oxygen for 6 h, there remained no significant difference in glutamate content or in the glutamate/glutamine ratio between these animals and animals similarly exposed to room air. These results imply that the observed decrease in glutamine synthetase activity does not globally influence the glutamate content of the brain.
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http://dx.doi.org/10.1016/0006-8993(91)91722-d | DOI Listing |
Front Plant Sci
December 2024
School of Hydraulic Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou, China.
Water-saving irrigation and the mixed application of controlled-release nitrogen fertilizer (CRNF) and common urea (CU; with a higher nitrogen release rate) have shown promise in improving rice yield with high resource use efficiency. However, the physiological mechanism underlying this effect remains largely unknown. This study involved a field experiment on rice in Jingzhou City, Central China, in 2020 and 2021.
View Article and Find Full Text PDFActa Pharmacol Sin
January 2025
Department of Anatomy and Convergence Medical Science, College of Medicine, Institute of Medical Science, Tyrosine Peptide Multiuse Research Group, Anti-aging Bio Cell Factory Regional Leading Research Center, Gyeongsang National University, Jinju, Gyeongnam, Republic of Korea.
Glutamine synthetase (GS) plays a crucial role in the homeostasis of the glutamate-glutamine cycle in the brain. Hypoactive GS causes depressive behaviors. Under chronic stress, GS has no change in expression, but its activity is decreased due to nitration of tyrosine (Tyr).
View Article and Find Full Text PDFCells
December 2024
Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA 30907, USA.
Diabetic retinopathy, a major cause of vision loss, is characterized by neurovascular changes in the retina. The lack of effective treatments to preserve vision in diabetic patients remains a significant challenge. A previous study from our laboratory demonstrated that 12-week treatment with MDL 72527, a pharmacological inhibitor of spermine oxidase (SMOX, a critical regulator of polyamine metabolism), reduced neurodegeneration in diabetic mice.
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December 2024
College of Food Science &Technology, Yunnan Agricultural University, Kunming 650201, China.
Chlorogenic acid (CGA), a polyhydroxy phenolic acid, has been extensively studied for its antimicrobial properties. () threatens food safety by forming biofilms. This study aimed to investigate the mechanism of CGA against and its biofilm.
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January 2025
General Surgery Department, The First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei, China.
Several members of the NIMA-related kinase (NEK) family have been implicated in tumor progression; however, the role and underlying mechanisms of NEK8 in gastric cancer (GC) remain unclear. This study revealed a significant upregulation of NEK8 in GC, identifying it as an independent prognostic marker in patients with GC. Consistent with these findings, NEK8 silencing substantially impeded GC aggressiveness both in vitro and in vivo, while its overexpression produced the opposite effect.
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