Background: Intestinal circulation and mesenteric arterial (MA) reactivity may play a role in preparing the fetus for enteral nutrition. We hypothesized that MA vasoreactivity changes with gestation and vasodilator pathways predominate in the postnatal period.
Methods: Small distal MA rings (0.5-mm diameter) were isolated from fetal (116-d, 128-d, 134-d, and 141-d gestation, term ~ 147 d) and postnatal lambs. Vasoreactivity was evaluated using vasoconstrictors (norepinephrine (NE) after pretreatment with propranolol and endothelin-1(ET-1)) and vasodilators (NO donors A23187 and s-nitrosopenicillamine (SNAP)). Protein and mRNA assays for receptors and enzymes (endothelin receptor A, alpha-adrenergic receptor 1A (ADRA1A), endothelial NO synthase (eNOS), soluble guanylyl cyclase (sGC), and phosphodiesterase5 (PDE5)) were performed in mesenteric arteries.
Results: MA constriction to NE and ET-1 peaked at 134 d. Relaxation to A23187 and SNAP was maximal after birth. Basal eNOS activity was low at 134 d. ADRA1A mRNA and protein increased significantly at 134 d and decreased postnatally. sGC and PDE5 protein increased from 134 to 141 d.
Conclusion: Mesenteric vasoconstriction predominates in late-preterm gestation (134 d; the postconceptional age with the highest incidence of necrotizing enterocolitis (NEC)) followed by a conversion to vasodilatory influences near the time of full-term birth. Perturbations in this ontogenic mechanism, including preterm birth, may be a risk factor for NEC.
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http://dx.doi.org/10.1038/pr.2015.260 | DOI Listing |
Nutr Res
January 2025
Department of Molecular Medicine, University of Padova, Padova, Italy; IMDEA-Food, Madrid, Spain. Electronic address:
l-Theanine is a unique non-protein amino acid found abundantly in tea leaves. Interest in its potential use as a dietary supplement has surged recently, especially claims related to promoting relaxation and cognitive enhancement. This review surveys the chemistry, metabolism, and purported biological activities of l-theanine.
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January 2025
Laboratory of Microbial Genetics, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India. Electronic address:
Nitric oxide synthases (NOSs) are heme-based monooxygenases that catalyze the NADPH-dependent oxidation of L-arginine to produce NO and L-citrulline. Over the past five years, the identification and characterization of NOS homologs in cyanobacteria have significantly advanced our understanding of these enzymes. However, the precise mechanisms through which NOS-derived NO influences nitrogen metabolism remain incompletely elucidated.
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December 2024
College of Ecology and Environment, Chengdu University of Technology, Sichuan, 610059, China; Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, Lanzhou University, Lanzhou, 730000, China; Key Laboratory of Monitoring for Heavy Metal Pollutants, Ministry of Ecology and Environment, Hunan, 410019, China. Electronic address:
With the intensification of climate change coupled with the inadequate agricultural management in certain regions, plants face numerous challenges due to various abiotic stresses. Stress associated proteins (SAPs) are essential functional genes in plants for coping with stress. This research provides a functional analysis of OsSAP17, a protein belonging to the SAP family in rice.
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Department of Thoracic Surgery, Renmin Hospital of Wuhan University, Wuhan, China.
While recent studies suggested a potential causal link between type 1 diabetes mellitus (T1DM) but not type 2 diabetes mellitus (T2DM) and idiopathic pulmonary fibrosis (IPF), the involved mechanism remains unclear. Here, using a Mendelian randomization (MR) approach, we verified the causal relationship between the two types of diabetes mellitus and IPF and investigated the possible role of inflammation in the association between diabetes mellitus and IPF. Based on genome-wide association study (GWAS) summary data of T1DM, T2DM, and IPF, the univariable MR, multivariable MR (MVMR), and mediation MR were successively used to analyze the causal relationship.
View Article and Find Full Text PDFMedicine (Baltimore)
January 2025
Renmin Hospital of Wuhan University, Wuhan, Hubei Province, People's Republic of China.
Colorectal cancer (CRC) is one of the most common cancers worldwide and inflammation is believed to play an important role in CRC. In this study, we comprehensively analyzed the causal association between 91 circulating inflammatory cytokines and the risk of CRC using Mendelian randomization (MR). Based on genome-wide association study summary statistics, we examined the causal effects of 91 circulating inflammatory cytokines on CRC.
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