The Effect of Calcium Ions on Resting Membrane Potential.

Biology (Basel)

Department of Biology, University of Kentucky, Lexington, KY 40506, USA.

Published: September 2024

Regulating membrane potential is key to cellular function. For many animal cells, resting membrane potential is predominantly driven by a family of K2P (two-pore domain) potassium channels. These channels are commonly referred to as leak channels, as their presence results in the membrane being permeable to K ions. These channels, along with various pumps and exchangers, keep the cell resting membrane potential (Rp) relatively close to potassium's equilibrium potential (E); however, in many cells, the resting membrane potential is more depolarized than the E due to a small Na ion leak. Raising [Ca] (extracellular Ca concentration) can result in hyperpolarization of the membrane potential from the resting state. The mechanism for this hyperpolarization likely lies in the blockage of a Na leak channel (NALCN) and/or voltage-gated Na channels. The effects may also be connected to calcium-activated potassium channels. Using , we here illustrate that changing [Ca] from 0.5 to 3 mM hyperpolarizes the muscle. Replacing NaCl with LiCl or choline chloride still led to hyperpolarization when increasing [Ca]. Replacing CaCl with BaCl results in depolarization. K2P channel overexpression in the larval muscle greatly reduces the effects of [Ca] on cell membrane potential, likely because potential is heavily driven by the E in these muscles. These experiments provide an understanding of the mechanisms behind neuronal hypo-excitability during hypercalcemia, as well as the effects of altered expression of K2P channels on membrane potential.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC11428845PMC
http://dx.doi.org/10.3390/biology13090750DOI Listing

Publication Analysis

Top Keywords

membrane potential
32
resting membrane
16
potential
10
membrane
9
cells resting
8
potassium channels
8
channels
7
resting
5
calcium ions
4
ions resting
4

Similar Publications

Background: Extracellular vesicles (EVs) play a crucial role in intraspecies and interspecies communication, significantly influencing physiological and pathological processes. Outer membrane vesicles (OMVs) secreted by Gram-negative bacteria are rich in components from the parent cells and are important for bacterial communication, immune evasion, and pathogenic mechanisms. However, the extraction and purification of OMVs face numerous challenges due to their small size and heterogeneity.

View Article and Find Full Text PDF

Preventive effect of sea bass protein-based high internal phase Pickering emulsion loaded with astaxanthin on DEHP-induced liver lipid metabolism disorder.

Int J Biol Macromol

December 2024

State Key Laboratory of Marine Food Processing and Safety Control, Dalian Polytechnic University, Dalian 116034, Liaoning, China; Academy of Food Interdisciplinary Science, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, Liaoning, China; National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, Liaoning, China. Electronic address:

The present study was to investigate the effect of the astaxanthin high internal phase Pickering emulsion (H-AXT) on DEHP-induced liver lipid metabolism disorder and to demonstrate its possible protective mechanism. We have developed an antioxidant activity emulsion system to deliver astaxanthin into the liver to maximize its ability to protect the liver. In vitro, H-AXT intervention inhibited oxidative stress restored the level of mitochondrial membrane potential to 90 % of that of normal LO2 cells, and alleviated the imbalance of energy metabolism by protecting mitochondrial structure and function.

View Article and Find Full Text PDF

Thymidine phosphorylase participates in platelet activation and promotes inflammation in rheumatoid arthritis.

Toxicol Appl Pharmacol

December 2024

Department of Rheumatology and Clinical Immunology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China. Electronic address:

The elevated risk of cardiovascular disease (CVD) associated with inflammatory rheumatic diseases has long been recognized. Patients with established rheumatoid arthritis (RA) have a higher mortality rate compared to the general population due to abnormal platelet activation. Thymidine phosphorylase (TYMP) plays a crucial role in platelet activation and thrombosis, following bridging the link between RA and CVD.

View Article and Find Full Text PDF

A model using the rigid body multi-cellular framework (RBMCF) is implemented to investigate the mechanisms of buckling of an epithelial monolayer. Specifically, the deformation of a monolayer of epithelial cells which are attached to a basement membrane and the surrounding stromal tissue. The epithelial monolayer , supporting basement membrane and stromal tissue are modelled using two separate vertex dynamics models (one for the epithelial monolayer layer and one for the basement membrane and stromal tissue combined) and interactions between the two are considered using the RBMCF to ensure biologically realistic interactions.

View Article and Find Full Text PDF

Mitochondrial transplantation reconstructs the oxidative microenvironment within fibroblasts to reverse photoaging.

Biochem Biophys Res Commun

December 2024

State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi Clinical Research Center for Oral Diseases, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, Xi'an, 710032, People's Republic of China.

Fibroblast-mediated oxidative stress is a pivotal factor in the pathogenesis of skin photoaging, predominantly induced by UVA radiation. Diverging from traditional strategies that concentrate on the reduction of reactive oxygen species (ROS), the present study implements mitochondrial transplantation as an innovative therapeutic approach. The objective of this study is to reestablish the oxidative microenvironment and to effectively rejuvenate cellular functionality through the direct introduction of healthy and vibrant mitochondria.

View Article and Find Full Text PDF

Want 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!