title: [Uptake of cyclic adenosine-3,5-monophosphate by cultured mammalian cells and frog muscles].
abstract: Uptake of 3H-cAMP by isolated frog sartorii muscles and cultured mouse 3T3 and 3T6 cells was studied. It was shown that after 1-2 hours of incubation the intracellular level of cAMP in frog muscles reached 10-20% of its concentration in the incubation medium. About 50% of intracellular radioactivity was represented by chromatographically pure cAMP which testifies to the insignificant cAMP metabolism rate. In the experiments with 3T3 and 3T6 cells the influence of possible admixtures and degradation products on 3H-cAMP uptake was revealed. To avoid these influences it is necessary to measure the uptake of cAMP in the presence of theophylline and with abundance of adenosine. In such experimental conditions the intracellular level of cAMP after 1 hour of incubation did not exceed 10% of its extracellular level, which is similar to values obtained on frog muscles. Permeability coefficient of cAMP for membrane of frog muscles and 3T3 and 3T6 cells was about 10(-9)-10(-8) cm X sec-1.
mesh_terms: D000241:Adenosine / Q000494:pharmacology; D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured / Q000378:metabolism*; D002852:Chromatography, Ion Exchange; D002854:Chromatography, Paper; D000242:Cyclic AMP / Q000032:analysis / Q000378:metabolism*; D066298:In Vitro Techniques; D051379:Mice; D009132:Muscles / Q000187:drug effects / Q000378:metabolism; D011896:Rana temporaria; D013806:Theophylline / Q000494:pharmacology; D014316:Tritium
chemical_list: D014316:Tritium; D013806:Theophylline; D000242:Cyclic AMP; D000241:Adenosine
vernacular_title: Postuplenie tsiklicheskogo adenozin-3,5-monofosfata v kul'tiviruemye keltki mlekopitaiushchikh i myshtsy liagushki.