The cortical collecting duct (CCD), which is involved in renal potassium (K) excretion, expresses cytochrome P450 (CYP)-epoxygenase. Here, we examined the effect of high dietary K on renal expression of CYP2C23 and CYP2J2 in the rat, as well as the role of CYP-epoxygenase-dependent metabolism of arachidonic acid in the regulation of Ca(2+)-activated big-conductance K (BK) channels. By Western blot analysis, high dietary K stimulated the expression of CYP2C23 but not CYP2J2 and increased 11,12-epoxyeicosatrienoic acid (11,12-EET) levels in isolated rat CCD tubules. Application of arachidonic acid increased BK channel activity, and this occurred to a greater extent in rats on a high-K diet compared with a normal-K diet. This effect was unlikely due to arachidonic acid-induced changes in membrane fluidity, because 11,14,17-eicosatrienoic acid did not alter BK channel activity. Inhibiting CYP-epoxygenase but not cyclooxygenase- or CYP-omega-hydroxylase-dependent pathways completely abolished the stimulatory effect of arachidonic acid on BK channel activity. In addition, application of 11,12-EET mimicked the effect of arachidonic acid on BK channel activity, even in the presence of CYP-epoxygenase inhibition. This effect seemed specific to 11,12-EET, because both 8,9- and 14,15-EET failed to stimulate BK channels. Finally, inhibition of CYP-epoxygenase abolished iberiotoxin-sensitive and flow-stimulated but not basal net K secretion in isolated microperfused CCD. In conclusion, high dietary K stimulates the renal CYP-epoxygenase pathway, which plays an important role in activating BK channels and flow-stimulated K secretion in the CCD.
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http://dx.doi.org/10.1681/ASN.2008040427 | DOI Listing |
Nat Commun
January 2025
Institute for Experimental Immunology and Imaging, University Hospital Essen, Essen, Germany.
Multimodal imaging by matrix-assisted laser desorption ionisation mass spectrometry imaging (MALDI MSI) and microscopy holds potential for understanding pathological mechanisms by mapping molecular signatures from the tissue microenvironment to specific cell populations. However, existing software solutions for MALDI MSI data analysis are incomplete, require programming skills and contain laborious manual steps, hindering broadly applicable, reproducible, and high-throughput analysis to generate impactful biological discoveries. Here, we present msiFlow, an accessible open-source, platform-independent and vendor-neutral software for end-to-end, high-throughput, transparent and reproducible analysis of multimodal imaging data.
View Article and Find Full Text PDFPostgrad Med J
January 2025
Shandong University of Traditional Chinese Medicine Affiliated Hospital, No. 42 Wenhua West Road, Lixia District, Jinan, Shandong Province 250011, China.
Background: The formation of gallstones is a multifactorial process involving lifestyle habits, lipid metabolism disorders, and genetic factors. This study aims to explore the association between 19 types of dietary fatty acids and gallstone disease using large-scale population data, assess the correlation between dietary fatty acids and serum fatty acids, and investigate the causal relationship between plasma lipids and gallstone disease from a genetic perspective.
Methods: We employed a cross-sectional study design, combined with logistic regression analysis to evaluate the association between dietary fatty acids and gallstone disease.
Nutrients
January 2025
State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, China.
Objectives: Polysaccharides from are known to have several bioactive effects. Previous studies have found that low-molecular-weight polysaccharide (GP1) is degraded by and promotes the production of beneficial bacteria and metabolites, which improves immune disorder and intestinal injury, and then enhances the body's immune regulation ability. However, the immune regulation effect of GP1 on a healthy body has not been studied.
View Article and Find Full Text PDFPharmaceuticals (Basel)
January 2025
Health Sciences Postgraduate Program, São Francisco University-USF, Bragança Paulista 12916-900, SP, Brazil.
Background/objectives: This study investigates the metabolic profile of a single dose of etodolac in healthy volunteers, focusing on pharmacokinetics, clinical parameters, and metabolomic variations to identify biomarkers and pathways linked to drug response, efficacy, and safety.
Methods: Thirty-seven healthy volunteers, enrolled after rigorous health assessments, received a single dose of etodolac (Flancox 500 mg). Pharmacokinetic profiles were determined using tandem mass spectrometry analysis, and the metabolomic profiling was conducted using baseline samples (pre-dose) and samples at maximum drug concentration (post-dose) via liquid chromatography coupled with a quadrupole time-of-flight mass spectrometer.
Int J Mol Sci
January 2025
Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
Cadmium (Cd) pollution poses an important problem, but limited information is available about the toxicology effects of Cd on freshwater invertebrates. We investigated the accumulation, oxidative stress, microbial community changes, and transcriptomic alterations in apple snails ) under Cd stress. The snails were exposed to the 10 μg/L Cd solution for 16 days, followed by a 16-day elimination period.
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