Objective: Coupled oscillations of 50-110 min in insulin and glucose have been found previously in healthy men under continuous enteral nutrition. Because L-arginine induces insulin release as glucose does, we tested the hypothesis that L-arginine can also display such an ultradian rhythm.
Research Design And Methods: Seven healthy male subjects participated in one experimental night during which blood was sampled every 10 min from 2300 to 0700. Plasma glucose, C-peptide, and L-arginine levels were measured simultaneously. The insulin secretion rate (ISR) was calculated from plasma C-peptide levels by a deconvolution procedure.
Results: Plasma glucose followed the recognizable profiles, with oscillations closely linked to similar changes in the ISR. Pulse analysis of L-arginine profiles revealed significant oscillations linked to glucose and ISR oscillations, with the highest cross-correlation coefficients at time lag 0 ranging from 0.380 to 0.680 for glucose and L-arginine and from 0.444 to 0.726 for ISR and L-arginine (P < 0.01). The mean period of L-arginine oscillations was 77.2 +/- 6.2 min, and their mean amplitude was 19.9 +/- 1.7%, similar to that of glucose (17.0 +/- 1.9%), when expressed as the percentage of mean overnight levels.
Conclusions: This newly discovered ultradian rhythm of L-arginine and its coupling with glucose and ISR oscillations sheds new light on the regulation of L-arginine, the substrate of numerous metabolic pathways, including nitric oxide synthesis. These oscillations may be of significance in conditions of hyperinsulinemia or abnormal glucose tolerance.
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http://dx.doi.org/10.2337/diacare.26.1.168 | DOI Listing |
Tree Physiol
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Hubei Key Laboratory of Spices & Horticultural Plant Germplasm Innovation & Utilization, College of Horticulture and Gardening, Yangtze University, Jingzhou, Hubei 434025, China.
Root-associated endophytic fungi can create symbiotic relationships with trees to enhance stress tolerance, but the underlying mechanisms, especially with regard to waterlogging tolerance, remain unclear. This study aimed to elucidate the effects of Funneliformis mosseae and Serendipita indica on the growth, root cross-section structure, and root transcriptional responses of peach under waterlogging stress, with a focus on polyamine and proline metabolism. Genes and transcription factors associated with secondary cell wall biosynthesis were selected, and their expression profiles were analyzed.
View Article and Find Full Text PDFJ Biomol NMR
January 2025
Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
The NMR signals from protein sidechains are rich in information about intra- and inter-molecular interactions, but their detection can be complicated due to spectral overlap as well as conformational and hydrogen exchange. In this work, we demonstrate a protocol for multi-dimensional solid-state NMR spectral editing of signals from basic sidechains based on Hadamard matrix encoding. The Hadamard method acquires multi-dimensional experiments in such a way that both the backbone and under-sampled sidechain signals can be decoded for unambiguous editing in the N spectral frequency dimension.
View Article and Find Full Text PDFNPJ Sci Food
January 2025
Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, National Engineering Research Center of Edible Fungi, Key Laboratory of Edible Fungi Resources and Utilization (South), Ministry of Agriculture, the People's Republic of China, Shanghai, 201403, China.
The ENaC receptor acts as a taste receptor to recognize and perceive salty substances. This study explored the mechanisms by which the ENaC taste receptor recognizes and binds mushroom-derived salty peptides using molecular interaction and molecular simulation. The three subunits α, β, and γ of the ENaC taste receptor (SCNN1α, SCNN1β, and SCNN1γ) showed different recognition characteristics for the salty peptide.
View Article and Find Full Text PDFAm J Physiol Gastrointest Liver Physiol
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USDA/ARS Children's Nutrition Research Center, Section of Pediatric Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Baylor College of Medicine, Houston, Texas USA.
Int Immunopharmacol
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Department of Colorectal Surgery, Xinchang People's Hospital, Affiliated Xinchang Hospital, Wenzhou Medical University, Xinchang, Zhejiang 312500, China. Electronic address:
Concerning the progression of societies and the evolution of lifestyle and dietary habits, the potential for the development of human malignancies, particularly colorectal cancer (CRC), has markedly escalated, positioning it as one of the most prevalent and lethal forms of cancer globally. Empirical evidence indicates that the metabolic processes of cancerous and healthy cells can significantly impact immune responses and the fate of tumors. Arginine, a multifaceted amino acid, assumes a crucial and paradoxical role in various metabolic pathways, as certain tumors exhibit arginine auxotrophy while others do not.
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