Biomaterial Database

Effects of Ca2+ on the contractility and Sr2+ accumulation in the quail oviductal smooth muscle. 1982

O Arjamaa

There occur strong spontaneous contractions in the avian oviduct, which are considered to effect the locus of the ovum during ovum transport. Previously it has been shown that stretch regulates these contractions by means of some unknown mechanisms in this tissue. When a transversal strip, cut from the proximal magnum of the oviduct, was first kept at the length (LO = length in situ) and then stretched to the length 200% LO the total integrated area of contractions increased 3.67 +/- 0.63 (6) times greater (p less than 0.01) than the contractility at the length LO. Ca2+ concentration of 5 mM increased the total integrated area of the contractions 1.42 +/- 0.22 (7) greater than the control while the increase at 8 mM was only 1.17 +/- 0.30 (7). 0.5 mM Ca2+ decreased the contractility to 0.72 +/- 0.15 (7). In a 50 microM EGTA containing solution, the contractility decreased in a few minutes. Sr2+, used as an indirect tracer of Ca2+, accumulated both in control and stretched strips in the sarcoplasmic reticulum, the mitochondria, and the sarcolemma. The electron-dense deposits were, however, most clearly seen in the sarcolemma. Compared to the Sr2+ accumulating sites in erythrocytes, deposits were on the outer side of the cell membrane, thus suggesting the glycocalyx as an important site for Ca2+ exchange in this smooth muscle. The sarcolemmal invaginations, caveolae, accumulated Sr2+ similarly to other parts of the sarcolemma. During ovum transport, stretch changes the Ca2+ accessibility to muscle cells, and at structural level, this takes place in the sarcolemma.

UI	MeSH Term	Description	Entries
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
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
D009940	Organoids	An organization of cells into an organ-like structure. Organoids can be generated in culture, e.g., self-organized three-dimensional tissue structures derived from STEM CELLS (see MICROPHYSIOLOGICAL SYSTEMS). They are also found in certain NEOPLASMS.	Organoid
D010057	Oviducts	Ducts that serve exclusively for the passage of eggs from the ovaries to the exterior of the body. In non-mammals, they are termed oviducts. In mammals, they are highly specialized and known as FALLOPIAN TUBES.	Oviduct
D010066	Ovum Transport	Transport of the OVUM or fertilized ovum (ZYGOTE) from the mammalian oviduct (FALLOPIAN TUBES) to the site of EMBRYO IMPLANTATION in the UTERUS.
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
D003370	Coturnix	A genus of BIRDS in the family Phasianidae, order GALLIFORMES, containing the common European and other Old World QUAIL.	Japanese Quail,Coturnix japonica,Japanese Quails,Quail, Japanese,Quails, Japanese
D005260	Female		Females
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
D013324	Strontium	An element of the alkaline earth family of metals. It has the atomic symbol Sr, atomic number 38, and atomic weight 87.62.