Contractile Function
Contractile Function - Related Videos
08:08
Measurement of Cytosolic Ca2+ in Isolated Contractile Lymphatics
0 Views •
Cited by 24 •
2011
We introduce an approach to evaluate the cytosolic Ca2+ concentration in isolated lymphatics to study Ca2+-dependent and Ca2+-sensitizing mechanisms of lymphatic smooth muscle contraction.
06:02
Development of an In Vitro Assay to Evaluate Contractile Function of Mesenchymal Cells that Underwent Epithelial-Mesenchymal Transition
0 Views •
Cited by 16 •
2016
Here, we describe the development and application of a gel contraction assay for evaluating contractile function in mesenchymal cells that underwent epithelial-mesenchymal transition.
02:15
The Contractile Ring
0 Views •
2023
Contractile rings are composed of microfilaments and are responsible for separating the daughter cells during cytokinesis. Contractile ring assembly proceeds along with other cell cycle events; however, very few mechanistic details are known about the timing and coordination of the contractile rings with the cell cycle. A small GTPase, RhoA, controls the function and assembly of the contractile ring. RhoA belongs to the Ras superfamily of proteins. The activation of formins by RhoA promotes...
02:15
The Contractile Ring
0 Views •
2021
Contractile rings are composed of microfilaments and are responsible for separating the daughter cells during cytokinesis. Contractile ring assembly proceeds along with other cell cycle events; however, very few mechanistic details are known about the timing and coordination of the contractile rings with the cell cycle. A small GTPase, RhoA, controls the function and assembly of the contractile ring. RhoA belongs to the Ras superfamily of proteins. The activation of formins by RhoA promotes...
14:02
Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles
0 Views •
Cited by 53 •
2012
We describe a method to directly measure muscle force, muscle power, contractile kinetics and fatigability of isolated skeletal muscles in an in vitro system using field stimulation. Valuable information on Ca2+ handling properties and contractile machinery of the muscle can be obtained using different stimulating protocols.
FAQs
Calcium availability determines how strongly and how long regulatory proteins remain activated. When calcium signaling permits myosin to interact with actin, ATP energy is converted into mechanical force. Changes in calcium entry, release, or removal can therefore alter both tension development and relaxation, giving pharmacological studies a mechanism for linking drug action to changes in muscle performance.
The amount of available calcium influences the extent of regulatory protein activation, while the persistence of that signal influences how long actin and myosin can interact. A larger or more sustained calcium signal can increase force or prolong contraction, whereas reduced availability can limit tension. These relationships help explain drug-induced changes in contractile magnitude and timing.
Cardiac, smooth, and skeletal muscle provide distinct tissue contexts for examining drug effects on force generation, contraction rate, and relaxation. Comparing these tissues can show whether a pharmacological response is broadly related to muscle contractility or more specific to a particular functional system. This distinction is important when evaluating desired therapeutic actions alongside possible effects in other tissues.
Force describes the magnitude of tension produced, contraction rate describes how quickly contractile activity changes, and relaxation reflects how the tissue returns from an active state. These readouts capture different dimensions of drug response, so a compound may alter one without producing the same change in the others. Together, they provide a more complete assessment of contractile behavior.
A pharmacological assessment compares contractile measurements before and after examining a drug’s effect on muscle or another force-generating tissue. Investigators can evaluate changes in force, rate, and relaxation, then relate those outcomes to altered calcium-dependent regulation. This approach helps distinguish effects on tension development from effects on the timing or recovery of contraction.
Measurements of contractile function can reveal whether a drug increases or decreases force, changes the rate of contraction, or modifies relaxation. The pattern of responses helps characterize the drug’s functional effects rather than relying on a single endpoint. Such data can support evaluation of therapeutic activity and identify responses that may signal an adverse pharmacological effect.
Contractility is relevant wherever force-generating tissues contribute to organ activity. Pharmacological studies therefore use changes in cardiac, smooth, or skeletal muscle performance to investigate potential treatments for cardiovascular, respiratory, and gastrointestinal disorders. The resulting force, rate, and relaxation data can help determine whether a treatment produces the intended functional response and whether unwanted contractile changes require attention.