In vitro experiments were performed in rat colon to define the role of calcium in the regulation of electrolyte transport. Neither basal net sodium absorption (JNanet) nor JClnet was affected by varying serosal calcium from 0 to 3.0 mM, but both were decreased by 4.8 mM calcium. Removal of serosal calcium completely inhibited the effect of bethanechol, a muscarinic cholinergic agonist, which inhibits neutral sodium-chloride absorption in 1.2 mM calcium. In contrast, theophylline significantly decreased JNanet and JClnet both in the presence and absence of calcium, but the effects of theophylline were significantly less in calcium-free media. In 3.0 mM calcium bethanechol inhibited JCLnet significantly greater than JNanet and in 4.8 mM calcium bethanechol decreased JClnet equivalent to the increase in short-circuit current without significantly altering JNanet. We conclude that 1) high [Ca2+] inhibits net sodium and net chloride absorption; 2) the alteration of electrolyte transport by bethanechol is dependent on extracellular calcium, and the alteration of electrolyte transport by theophylline is not dependent on extracellular calcium but may be dependent on intracellular calcium; and 3) in addition to inhibition of neutral NaCl absorption, bethanechol stimulates chloride secretion.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1152/ajpgi.1983.244.5.G552 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Protective Coating of Single-Crystalline Ni-Rich Cathode Enables Fast Charging in All-Solid-State Batteries.
ACS Nano
January 2025
Battery and Electrochemistry Laboratory (BELLA), Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, Karlsruhe 76131, Germany.
Improving interfacial stability between cathode active material (CAM) and solid electrolyte (SE) is vital for developing high-performance all-solid-state batteries (ASSBs), with compatibility issues among the cell components representing a major challenge. CAM surface coating with a chemically inert ion conductor is a promising approach to suppress side reactions occurring at the cathode interfaces. Another strategy to mitigate mechanical degradation involves utilizing single-crystalline particle morphologies.
View Article and Find Full Text PDFNanoscale Hydrophobicity of Transport Barriers in the Nuclear Pore Complex as Compared with the Liquid/Liquid Interface by Scanning Electrochemical Microscopy.
Anal Chem
January 2025
Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, United States.
The nuclear pore complex (NPC) is the proteinous nanopore that solely regulates molecular transport between the nucleus and cytoplasm of a eukaryotic cell. Hypothetically, the NPC utilizes the hydrophobic barriers based on the repeats of phenylalanine-glycine (FG) units to selectively and efficiently transport macromolecules. Herein, we quantitatively assess the hydrophobicity of transport barriers confined in the nanopore by applying scanning electrochemical microscopy (SECM).
View Article and Find Full Text PDFExpression and function of Connexin 43 and Connexin 37 in the murine zona glomerulosa.
Physiol Rep
February 2025
Berlin Institute of Health at Charité, Universitätsmedizin Berlin, Center of Functional Genomics, Berlin, Germany.
The zona glomerulosa (ZG) synthesizes the mineralocorticoid aldosterone. The primary role of aldosterone is the maintenance of volume and electrolyte homeostasis. Aldosterone synthesis is primarily regulated via tightly controlled oscillations in intracellular calcium levels in response to stimulation.
View Article and Find Full Text PDFEnhanced Antitumor Efficacy and Reduced Toxicity in Colorectal Cancer Using a Novel Multifunctional Rg3- Targeting Nanosystem Encapsulated with Oxaliplatin and Calcium Peroxide.
Int J Nanomedicine
January 2025
Department of Biopharmacy, School of Pharmaceutical Sciences, Jilin University, Changchun, People's Republic of China.
Article Synopsis
- Colorectal cancer (CRC) is a major cause of cancer deaths, and oxaliplatin (OXA) is a primary treatment that faces challenges due to the tumor microenvironment (TME).
- A new multifunctional nanosystem, Rg3-Lip-OXA/CaO, uses Ginsenoside Rg3 liposomes to target CRC cells, delivering OXA and calcium peroxide (CaO) together.
- Research showed that this nanosystem had good stability and release properties, effectively targeted cancer cells, and significantly suppressed tumor growth in mice, while also showing manageable acute toxicity.
Targeted Docking of Localized Hydrogen Bond for Efficient and Reversible Zinc-Ion Batteries.
Angew Chem Int Ed Engl
January 2025
Central South University, material science and engineering, 932 Lushan Road, 410083, Changsha, CHINA.
Hydrogen bond (HB) chemistry, a pivotal feature of aqueous zinc-ion batteries, modulates electrochemical processes through weak electrostatic interactions among water molecules. However, significant challenges persist, including sluggish desolvation kinetics and inescapable parasitic reactions at the electrolyte-electrode interface, associated with high water activity and strong Zn2+-solvent coordination. Herein, a targeted localized HB docking mechanism is activated by the polyhydroxy hexitol-based electrolyte, optimizing Zn2+ solvation structures via dipole interaction and reconstructing interfacial HB networks through preferential parallel adsorption.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!