Biomaterial Database

Ras proteins increase Ca(2+)-responsiveness of smooth muscle contraction. 1993

S Satoh, and H Rensland, and G Pfitzer

II. Physiologisches Institut, Universität Heidelberg, Germany.

G-proteins may be involved in receptor-mediated Ca(2+)-sensitization of smooth muscle contraction, but the responsible G-proteins are not yet known. Here we show that in beta-escin skinned mesenteric microarteries, H-ras p21 proteins, preactivated with GTP or GTP gamma S, increase force at constant submaximal Ca2+ (pCa 6.3) concentration dependently. The GTP-bound form of the wild-type H-ras p21 and the oncogenic mutant (p21[G12V]) were equally effective. The nucleotide-free and the inactive GDP-bound form of ras p21 had no effect on force. The tryosine kinase inhibitor, tryphostin, partially reversed the effect of the ras proteins in the GTP-bound form on force. Thus, ras proteins mimic the Ca(2+)-sensitizing effect of GTP gamma S and vasoconstrictors in mesenteric microarteries which may involve tyrosine phosphorylation.

UI	MeSH Term	Description	Entries
D008643	Mesentery	A layer of the peritoneum which attaches the abdominal viscera to the ABDOMINAL WALL and conveys their blood vessels and nerves.	Mesenteries
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
D009131	Muscle, Smooth, Vascular	The nonstriated involuntary muscle tissue of blood vessels.	Vascular Smooth Muscle,Muscle, Vascular Smooth,Muscles, Vascular Smooth,Smooth Muscle, Vascular,Smooth Muscles, Vascular,Vascular Smooth Muscles
D011518	Proto-Oncogene Proteins	Products of proto-oncogenes. Normally they do not have oncogenic or transforming properties, but are involved in the regulation or differentiation of cell growth. They often have protein kinase activity.	Cellular Proto-Oncogene Proteins,c-onc Proteins,Proto Oncogene Proteins, Cellular,Proto-Oncogene Products, Cellular,Cellular Proto Oncogene Proteins,Cellular Proto-Oncogene Products,Proto Oncogene Products, Cellular,Proto Oncogene Proteins,Proto-Oncogene Proteins, Cellular,c onc Proteins
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
D002463	Cell Membrane Permeability	A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.	Permeability, Cell Membrane
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D004928	Escin	Pentacyclic triterpene saponins, biosynthesized from protoaescigenin and barringtogenol, occurring in the seeds of AESCULUS. It inhibits edema formation and decreases vascular fragility.	Aescin,Aescusan,Escina,Eskuzan,Fepalitan,Feparil,Flebostasin,Opino,Reparil,beta-Aescin,beta-Escin,opino-biomo,beta Aescin,beta Escin,opino biomo,opinobiomo
D005260	Female		Females
D006160	Guanosine Triphosphate	Guanosine 5'-(tetrahydrogen triphosphate). A guanine nucleotide containing three phosphate groups esterified to the sugar moiety.	GTP,Triphosphate, Guanosine