Biomaterial Database

Contractile and endurance properties of feline triangularis sterni muscle. 1991

E van Lunteren

Department of Medicine, Case Western Reserve University, Cleveland, OH.

The triangularis sterni muscle has recently been found to play an active role in the modulation of airflow during expiration in several species; furthermore its electrical activity is influenced by many chemical and mechanical stimuli which influence breathing. To determine feline triangularis sterni contractile and endurance properties, strips of triangularis sterni and costal diaphragm muscle were removed from anesthetized ventilated cats, and studied in vitro. The isometric contractile kinetics of the two muscles were similar; contraction times were 37 +/- 2 and 36 +/- 1 ms for the triangularis sterni and diaphragm, respectively. However, the twitch to tetanic tension ratio of the triangularis sterni was lower than that of the diaphragm (0.19 +/- 0.01 versus 0.37 +/- 0.03; P less than 0.001), and the force frequency relationship of the triangularis sterni was located to the right of that of the diaphragm. Repetitive stimulation (40 Hz trains, duty cycle 0.33) produced a greater decline in force for the diaphragm than the triangularis sterni. The fatigue index (ratio of force at 2 min to initial force) was significantly higher for the triangularis sterni (0.31 +/- 0.04) than for the diaphragm (0.18 +/- 0.02; P less than 0.01). These data indicate that the contractile and endurance properties of the feline triangularis sterni are different in some but not all respects from those of the diaphragm, which may reflect adaptations to patterns of use during breathing.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
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
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
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
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
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
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
D066298	In Vitro Techniques	Methods to study reactions or processes taking place in an artificial environment outside the living organism.	In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In