Biomaterial Database

Potassium contractures in the mouse diaphragm: regional variation in the multiphasic response. 1988

Y N Singh, and W F Dryden

Department of Pharmacology, University of Alberta, Edmonton, Canada.

1. Submaximal potassium-induced contractures were studied in isolated mouse hemidiaphragms (HD) and compared with extensor digitorum longus (EDL) and soleus. 2. In the HD, the contracture was triphasic: an initial small, fast phase followed by a larger slow phase, and a late phase which was seen on prolonged exposure. 3. Costal segments of the HD responded to elevated potassium with a larger fast phase, while dorsal or ventral segments produced a larger slow phase. 4. In calcium-free solution, the fast phase appeared to be unaffected, while the slow phase was potentiated and its time course abbreviated. The late phase was greatly attenuated or abolished. 5. In the soleus, but not the EDL muscle, contracture amplitude in calcium-free solution was potentiated and the time course was shortened. 6. The characteristics of potassium-induced contractures of both the soleus and EDL muscles are to be seen in the response of the hemidiaphragm, but there is a regional variation in their proportional contribution which suggests a heterogeneity in diaphragm composition.

UI	MeSH Term	Description	Entries
D008813	Mice, Inbred ICR	An inbred strain of mouse that is used as a general purpose research strain, for therapeutic drug testing, and for the genetic analysis of CARCINOGEN-induced COLON CANCER.	Mice, Inbred ICRC,Mice, ICR,Mouse, ICR,Mouse, Inbred ICR,Mouse, Inbred ICRC,ICR Mice,ICR Mice, Inbred,ICR Mouse,ICR Mouse, Inbred,ICRC Mice, Inbred,ICRC Mouse, Inbred,Inbred ICR Mice,Inbred ICR Mouse,Inbred ICRC Mice,Inbred ICRC Mouse
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009435	Synaptic Transmission	The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.	Neural Transmission,Neurotransmission,Transmission, Neural,Transmission, Synaptic
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D012132	Respiratory Muscles	These include the muscles of the DIAPHRAGM and the INTERCOSTAL MUSCLES.	Ventilatory Muscles,Respiratory Muscle,Muscle, Respiratory,Muscle, Ventilatory,Muscles, Respiratory,Muscles, Ventilatory,Ventilatory Muscle
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D003964	Diaphragm	The musculofibrous partition that separates the THORACIC CAVITY from the ABDOMINAL CAVITY. Contraction of the diaphragm increases the volume of the thoracic cavity aiding INHALATION.	Respiratory Diaphragm,Diaphragm, Respiratory,Diaphragms,Diaphragms, Respiratory,Respiratory Diaphragms
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013779	Tetrodotoxin	An aminoperhydroquinazoline poison found mainly in the liver and ovaries of fishes in the order TETRAODONTIFORMES, which are eaten. The toxin causes paresthesia and paralysis through interference with neuromuscular conduction.	Fugu Toxin,Tarichatoxin,Tetradotoxin,Toxin, Fugu
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus