Objective: This study was designed to determine the effects of both intracellular and extracellular pH change on contractile activity and intracellular Ca(++) during spontaneous contractions, oxytocin, and depolarization-induced stimulation of human myometrium.
Study Design: Human myometrial tissue was obtained at elective caesarean delivery at term (37-41 completed weeks of gestation). Longitudinal strips were dissected and loaded with the calcium sensitive indicator Indo-1. Statistical significance was tested with the Student t test.
Results: Both intracellular and extracellular acidification significantly reduces or even abolishes phasic activity, whether it arises spontaneously or in the presence of oxytocin. These contractile changes can be accounted for by the changes in intracellular Ca(++). Alkalinization produced the opposite effects. However, baseline or maintained tension changes could not be accounted for by changes in intracellular Ca(++).
Conclusion: We suggest that the effects on phasic activity are due to the inhibition of L-type calcium entry and that, during maintained or baseline activity, pH-sensitive Ca(++) release, possibly from the sarcoplasmic reticulum occurs; but it is insufficient to overcome the inhibitory effects at the myofilaments. We conclude that alterations of pH significantly affect calcium signaling and force production in the human myometrium and may contribute to dysfunction in labor.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1067/mob.2003.229 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Bioinspired Antiswelling Hydrogel Sensors with High Strength and Rapid Self-Recovery for Underwater Information Transmission.
ACS Appl Mater Interfaces
January 2025
School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
Hydrogel-based sensors typically demonstrate conspicuous swelling behavior in aqueous environments, which can severely compromise the mechanical integrity and distort sensing signals, thereby considerably constraining their widespread applicability. Drawing inspiration from the multilevel heterogeneous structures in biological tissues, an antiswelling hydrogel sensor endowed with high strength, rapid self-recovery, and low swelling ratio was fabricated through a water-induced phase separation and coordination cross-linking strategy. A dense heterogeneous architecture was developed by the integration of "rigid" quadridentate carboxyl-Zr coordination bonds and "soft" hydrophobic unit-rich regions featuring π-π stacking and cation-π interactions into the hydrogels.
View Article and Find Full Text PDFDapagliflozin inhibits ferroptosis to improve chronic heart failure by regulating Nrf2/HO-1/GPX4 signaling pathway.
PLoS One
January 2025
Hebei General Hospital, Shijiazhuang City, Hebei Province, P.R. China.
Objective: To study the effect of Dapagliflozin on ferroptosis in rabbits with chronic heart failure and to reveal its possible mechanism.
Methods: Nine healthy adult male New Zealand white rabbits were randomly divided into Sham group (only thorax opening was performed in Sham group, no ascending aorta circumferential ligation was performed), Heart failure group (HF group, ascending aorta circumferential ligation was performed in HF group to establish the animal model of heart failure), and Dapagliflozin group (DAPA group, after the rabbit chronic heart failure model was successfully made in DAPA group). Dapagliflozin was given by force-feeding method.
Bioaerosol Characterization with Vibrational Spectroscopy: Overcoming Fluorescence with Photothermal Infrared (PTIR) Spectroscopy.
J Phys Chem A
January 2025
Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States.
Aerosols containing biological material (i.e., bioaerosols) impact public health by transporting toxins, allergens, and diseases and impact the climate by nucleating ice crystals and cloud droplets.
View Article and Find Full Text PDFHow well do empirical molecular mechanics force fields model the cholesterol condensing effect?
J Chem Phys
January 2025
School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom.
Membrane properties are determined in part by lipid composition, and cholesterol plays a large role in determining these properties. Cellular membranes show a diverse range of cholesterol compositions, the effects of which include alterations to cellular biomechanics, lipid raft formation, membrane fusion, signaling pathways, metabolism, pharmaceutical therapeutic efficacy, and disease onset. In addition, cholesterol plays an important role in non-cellular membranes, with its concentration in the skin lipid matrix being implicated in several skin diseases.
View Article and Find Full Text PDFPhytic acid-based nanomedicine against mTOR represses lipogenesis and immune response for metabolic dysfunction-associated steatohepatitis therapy.
Life Metab
December 2024
State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers and Xijing Hospital of Digestive Diseases, Air Force Medical University, Xi'an, Shaanxi 710032, China.
Metabolic dysfunction-associated steatohepatitis (MASH) is one of the most common chronic liver diseases and is mainly caused by metabolic disorders and systemic inflammatory responses. Recent studies have indicated that the activation of the mammalian (or mechanistic) target of rapamycin (mTOR) signaling participates in MASH progression by facilitating lipogenesis and regulating the immune microenvironment. Although several molecular medicines have been demonstrated to inhibit the phosphorylation or activation of mTOR, their poor specificity and side effects limit their clinical application in MASH treatment.
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!