Biomaterial Database

Agonist-induced myosin phosphorylation during isometric contraction and unloaded shortening in airway smooth muscle. 1992

C M Hai, and B Szeto

Division of Biology and Medicine, Brown University, Providence, Rhode Island 02912.

We measured myosin phosphorylation during isometric contraction at optimal length (Lo) and unloaded shortening induced by K(+)-depolarization, electrical stimulation, carbachol, histamine, and phorbol dibutyrate (PDB) in bovine trachealis. Peak myosin phosphorylation during unloaded shortening was lower than that during isometric contraction in response to all stimuli. The lower peak myosin phosphorylation during unloaded shortening appeared to be a stretch-sensitive response because myosin phosphorylation was either equally low or further reduced during the second unloaded shortening of preshortened tissues. Similar to peak myosin phosphorylation, steady-state myosin phosphorylation was also lower during unloaded shortening in carbachol-induced contractions. However, steady-state phosphorylation during unloaded shortening and isometric contraction were not significantly different in histamine- and PDB-induced contractions. Since the coupling between Ca2+ and myosin phosphorylation was not stretch sensitive, these results suggest the coexistence of stretch-sensitive and stretch-insensitive signal transduction mechanisms in the airway smooth muscle cell membrane, and the stretch-insensitive signal transduction mechanism might involve protein phosphorylation by protein kinase C.

UI	MeSH Term	Description	Entries
D007537	Isometric Contraction	Muscular contractions characterized by increase in tension without change in length.	Contraction, Isometric,Contractions, Isometric,Isometric Contractions
D009130	Muscle, Smooth	Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)	Muscle, Involuntary,Smooth Muscle,Involuntary Muscle,Involuntary Muscles,Muscles, Involuntary,Muscles, Smooth,Smooth Muscles
D009218	Myosins	A diverse superfamily of proteins that function as translocating proteins. They share the common characteristics of being able to bind ACTINS and hydrolyze MgATP. Myosins generally consist of heavy chains which are involved in locomotion, and light chains which are involved in regulation. Within the structure of myosin heavy chain are three domains: the head, the neck and the tail. The head region of the heavy chain contains the actin binding domain and MgATPase domain which provides energy for locomotion. The neck region is involved in binding the light-chains. The tail region provides the anchoring point that maintains the position of the heavy chain. The superfamily of myosins is organized into structural classes based upon the type and arrangement of the subunits they contain.	Myosin ATPase,ATPase, Actin-Activated,ATPase, Actomyosin,ATPase, Myosin,Actin-Activated ATPase,Actomyosin ATPase,Actomyosin Adenosinetriphosphatase,Adenosine Triphosphatase, Myosin,Adenosinetriphosphatase, Actomyosin,Adenosinetriphosphatase, Myosin,Myosin,Myosin Adenosinetriphosphatase,ATPase, Actin Activated,Actin Activated ATPase,Myosin Adenosine Triphosphatase
D010766	Phosphorylation	The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.	Phosphorylations
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.
D002217	Carbachol	A slowly hydrolyzed CHOLINERGIC AGONIST that acts at both MUSCARINIC RECEPTORS and NICOTINIC RECEPTORS.	Carbamylcholine,Carbacholine,Carbamann,Carbamoylcholine,Carbastat,Carbocholine,Carboptic,Doryl,Isopto Carbachol,Jestryl,Miostat,Carbachol, Isopto
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
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.
D006632	Histamine	An amine derived by enzymatic decarboxylation of HISTIDINE. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.	Ceplene,Histamine Dihydrochloride,Histamine Hydrochloride,Peremin