标题：Normal serum and lipoprotein-deficient serum give different expressions of excitability, corresponding to different stages of differentiation, in chicken cardiac cells in culture
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1982
卷号：79
期号：24
页码：7768-7772
DOI：10.1073/pnas.79.24.7768
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Monolayers of cardiac cells from 11-day-old chicken hearts have different properties when maintained in fetal calf serum or in a lipoprotein-deficient serum (LPDS). Cells in fetal calf serum have a resting potential near -60 mV; the rate of rise of the action potential is low (less than 10 V/sec); the action potential and the contraction are essentially unaffected by tetrodotoxin (TTX); and the beating properties are unaffected by muscarinic agents. Cells in LPDS have a resting potential near -75 mV, and a fast rise of the action potential (approximately equal to 100 V/sec) that is drastically decreased by TTX with a parallel abolition of contraction, and the beat is blocked by very low concentrations of muscarinic agonists. Cells that are physiologically fully responsive to TTX and to muscarinic agents have receptors that remain stable 24 hr after protein synthesis is blocked, whereas cells that are physiologically unresponsive to TTX and muscarinic agents have receptors that are rapidly degraded with half-lives between 9 hr (TTX receptor) and 14 hr (muscarinic receptor). Differences in the physiological and biochemical properties are accompanied by changes in the cholesterol contents of the cell membranes. The properties of cardiac cells cultured in normal serum are similar to those found for cells of chicken hearts in the very early embryonic stage, whereas those of cardiac cells cultured in LPDS correspond to the late embryonic stage.
