Biomaterial Database

Rubidium influx into rat skeletal muscles in relation to electrical activity. 1973

R P Kernan, and M McDermott

1. Rates of (86)Rb influx were compared in vivo over 2, 4 and 6 hr periods in various tonic and phasic muscles of rat following its I.P. injection. During the 2 hr period its influx rate into soleus was about 4 times that of the vastus with the EDL muscles at an intermediate rate. Uptake by diaphragm was fastest reaching equilibrium within 2 hr.2. Unilateral section of the sciatic nerve 48 hr before (86)Rb injection reduced isotope uptake into soleus to about 50% of its contralateral control muscle over a 4 hr period. In EDL muscles on the other hand nerve section increased influx by about 75% of control in conscious rats and more than doubled influx in anaesthetized rats.3. Tenotomy of soleus reduced (86)Rb influx to 40% of control, but tenotomy in EDL was without effect in influx.4. Uptake of urea into muscles within 5 min of its I.V. injection was used to determine the possibility of muscle blood flow determining (86)Rb influx. Accumulation of urea was not significantly different in control and denervated EDL muscles nor between soleus and vastus muscles in anaesthetized rats, so it seems unlikely that blood flow is important here.5. Membrane depolarization in response to addition of 30 mM rubidium to external bathing fluid was greater in the case of denervated than in control EDL muscles which was in keeping with the greater (86)Rb influx seen in the former muscles. The ouabain sensitivity of rubidium-induced depolarization in the denervated EDL muscles would suggest, however, that rubidium enters the fibres actively.

UI	MeSH Term	Description	Entries
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D009121	Muscle Denervation	The resection or removal of the innervation of a muscle or muscle tissue.	Denervation, Muscle,Denervations, Muscle,Muscle Denervations
D009129	Muscle Tonus	The state of activity or tension of a muscle beyond that related to its physical properties, that is, its active resistance to stretch. In skeletal muscle, tonus is dependent upon efferent innervation. (Stedman, 25th ed)	Muscle Tension,Muscle Tightness,Muscular Tension,Tension, Muscle,Tension, Muscular,Tightness, Muscle,Tonus, Muscle
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D010042	Ouabain	A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE.	Acocantherin,G-Strophanthin,Acolongifloroside K,G Strophanthin
D011868	Radioisotopes	Isotopes that exhibit radioactivity and undergo radioactive decay. (From Grant & Hackh's Chemical Dictionary, 5th ed & McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Daughter Isotope,Daughter Nuclide,Radioactive Isotope,Radioactive Isotopes,Radiogenic Isotope,Radioisotope,Radionuclide,Radionuclides,Daughter Nuclides,Daugter Isotopes,Radiogenic Isotopes,Isotope, Daughter,Isotope, Radioactive,Isotope, Radiogenic,Isotopes, Daugter,Isotopes, Radioactive,Isotopes, Radiogenic,Nuclide, Daughter,Nuclides, Daughter
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
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
D012413	Rubidium	An element that is an alkali metal. It has an atomic symbol Rb, atomic number 37, and atomic weight 85.47. It is used as a chemical reagent and in the manufacture of photoelectric cells.