Related Experiment Video
Updated: Jun 13, 2026

Contractility Measurements of Human Uterine Smooth Muscle to Aid Drug Development
Published on: January 26, 2018
[Changes of mitochondria membrane potential of the uterine smooth muscle under Mg2+ and Ca2+ influence]
Abstract:
Using the method of flow cytometry and potential-sensitive fluorescent dye TMRM the effect of divalent cations on the membrane potential of isolated myometrium mitochondria was studied. It was shown, that Mg2+ (7 mM) addition to the incubation medium induced mitochondrial membrane hyperpolarization. In the case of protonophore CCCP (1 microM) preliminary presence in the incubation medium, Mg2+ addition did not lead to membrane potential hyperpolarization. Addition of Ca24+ leads to membrane potential dissipation. Ca2+ -induced mitochondrial depolarization is the same as NaN3 (10 mM)-induced depolarization. It also was shown that Mg2+ (7 mM) preliminary presence in the incubation medium did not protect mitochondria from Ca2+ -induced depolarization.
Related Concept Videos
Smooth Muscle Contraction
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
Relaxation of Skeletal Muscles
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open.
Feedback Regulation of Calcium Concentration
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...

