title: Appearances of responses to glucagon in cultured neoatal rat heart cells.
abstract: Heart cells from neonatal rats have been cultured. The ability of 10(-5)M glucagon to stimulate adenylyl cyclase activity, and to increase the cAMP concentration and the beating rate in these cells was followed as a function of time in culture. The cultured cells show no response to 10(-5)M glucagon until 5 weeks. By contrast, the cells do respond to 10(-5)M epinephrine with an increase in beat rate, adenylyl cyclase activity and cAMP levels when freshly prepared or after 1 week in culture. Previous studies on the newborn rat heart, acutely isolated, have also shown that the neonatal rat heart is insensitive to glucagon until 4-5 weeks after birth. We conclude that the cultured neonatal rat heart cells can also mature in the same time frame with respect to a glucagon response.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D004285:Dogs; D004837:Epinephrine / Q000494:pharmacology; D005459:Fluorides / Q000494:pharmacology; D005934:Glucagon / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects* / Q000254:growth & development; D006339:Heart Rate / Q000187:drug effects; D009206:Myocardium / Q000378:metabolism; D051381:Rats; D013997:Time Factors
chemical_list: D005934:Glucagon; D000262:Adenylyl Cyclases; D005459:Fluorides; D004837:Epinephrine