The Ca(2+) activated K(+) channel K(ca)3.1 is expressed in a variety of tissues. In the gastric gland it is expressed in the basolateral cell membrane. To determine the functional significance of K(ca)3.1 activity for gastric acid secretion, gastric acid secretion was determined in isolated glands from gene targeted mice lacking functional K(ca)3.1 (K(ca)3.1(-/-)) and from their wild type littermates (K(ca)3.1(+/+)). According to BCECF-fluorescence cytosolic pH in isolated gastric glands was similar in K(ca)3.1(-/-) and K(ca)3.1(+/+) mice. Na(ca)-independent pH recovery (ΔpH/min) following an ammonium pulse, a measure of H(ca)/K(ca) ATPase activity, was, however, significantly faster in K(ca)3.1(-/-) than in K(ca)3.1(+/+) mice. Accordingly, the luminal pH was significantly lower and the acid content significantly higher in K(ca)3.1(-/-) than in K(ca)3.1(+/+) mice. The abundance of mRNA encoding H(ca)/K(ca) ATPase and KCNQ1 was similar in both genotypes. Increase of extracellular K(ca) concentrations to 35 mM (replacing Na(ca)/NMDG) and treatment with histamine (100 μM) significantly increased ΔpH/min to a larger extent in K(ca)3.1(+/+) than in K(ca)3.1(-/-) mice and dissipated the differences between the genotypes. Carbachol (100 μM) increased ΔpH/min in both genotypes but did not abolish the difference between K(ca)3.1(-/-) and K(ca)3.1(+/+) mice. In K(ca)3.1(+/+) mice the K(ca)3.1 opener DCEBIO (100 μM) did not significantly alter basal ΔpH/min but significantly blunted ΔpH/min in the presence of carbachol. In conclusion, K(ca)3.1 activity suppresses carbachol stimulated gastric acid secretion.
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http://dx.doi.org/10.1159/000329981 | DOI Listing |
J Oral Pathol Med
January 2025
Department of Oral and Maxillofacial Pathology, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil.
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Stem Cell Rev Rep
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Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
Background: The hypobaric hypoxic atmosphere can cause adverse reactions or sickness. The purpose of this study was to explore the preventive effect and mechanism of human umbilical cord mesenchymal stem cells (hUC-MSCs) on acute pathological injury in mice exposed to high-altitude.
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AMB Express
January 2025
Department of Agricultural Microbiology, Faculty of Agriculture, Ain Shams University, P.O. Box 68, Cairo, 11241, Egypt.
The increasing demand for natural alternatives to synthetic fungicides has prompted research into natural products like essential oils for postharvest disease management. This study investigated the antifungal, antioxidant, cytotoxic, and genotoxic potential of essential oil mixtures derived from oregano, rosemary, and mint against Penicillium digitatum, the predominant fungal pathogen causing green mold in orange fruits. P.
View Article and Find Full Text PDFNat Metab
January 2025
Tongji Shanxi Hospital, Shanxi Bethune Hospital, Shanxi Academy of Medical Science, Third Hospital of Shanxi Medical University, the Key Laboratory of Endocrine and Metabolic Diseases of Shanxi Province, Taiyuan, China.
Skeletal muscle is a critical organ in maintaining homoeostasis against metabolic stress, and histone post-translational modifications are pivotal in those processes. However, the intricate nature of histone methylation in skeletal muscle and its impact on metabolic homoeostasis have yet to be elucidated. Here, we report that mitochondria-rich slow-twitch myofibers are characterized by significantly higher levels of H3K36me2 along with repressed expression of Kdm2a, an enzyme that specifically catalyses H3K36me2 demethylation.
View Article and Find Full Text PDFActa Parasitol
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Centralized Instrumentation Laboratory, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai, 600 007, India.
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