title: Effect of aminophylline on calcium transport across the rat diaphragm.
abstract: Calcium accumulation in muscle strips isolated from rat diaphragm reached steady state after 90 min with intracellular to extracellular ratio (IN/OUT) of 3.0. Calcium uptake by rat diaphragm is a saturable and carrier mediated process that is significantly enhanced in the presence of aminophylline in a dose-dependent pattern that produced maximal effect at 18.75 micrograms/ml. A Lineweaver-Burk plot shows Jmax = 25 microM/hr per g dry wt and Kt = 3.19 mM for the control, and Jmax = 26 microM/hr per g dry wt and Kt = 2.27 mM in the presence of 18.75 micrograms/ml aminophylline. Aminophylline had no effect on cell volume and water of the diaphragmatic cells.
mesh_terms: D000628:Aminophylline / Q000494:pharmacology*; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D001834:Body Water / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D003964:Diaphragm / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D066298:In Vitro Techniques; D007424:Intracellular Fluid / Q000187:drug effects; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
chemical_list: D000628:Aminophylline; D002118:Calcium