TY - JOUR
T1 - Effect of triiodothyronine on cultured neonatal rat heart cells
T2 - Beating rate, myosin subunits and CK-isozymes
AU - Kessler-Icekson, Gania
PY - 1988/7
Y1 - 1988/7
N2 - The effect of thyroid hormone on cell contractility, myosin subunit composition and creatine kinase activity was explored in cultured rat myocytes. Triiodothyronine (5 nm) was administered to neonatal rat heart myocytes grown in chemically defined medium. The hormone induced a 30% enhancement in the rate of cell beating and a complete transition from β-to α-myosin heavy chain synthesis. Myosin light chains as well as creatine kinase activity and isozymic distribution were unaffected by the hormone. The arrest of spontaneous contraction by either membrane depolarization or Ca2+ channel blockage did not interfere with the shift towards α-myosin heavy chain predominance. We conclude that thyroid regulation of myosin subunits is confined to the molecule heavy subunits and occurs irrespective of cell contraction. Furthermore, the genomic expression of creatine kinase is not regulated by thyroid hormone.
AB - The effect of thyroid hormone on cell contractility, myosin subunit composition and creatine kinase activity was explored in cultured rat myocytes. Triiodothyronine (5 nm) was administered to neonatal rat heart myocytes grown in chemically defined medium. The hormone induced a 30% enhancement in the rate of cell beating and a complete transition from β-to α-myosin heavy chain synthesis. Myosin light chains as well as creatine kinase activity and isozymic distribution were unaffected by the hormone. The arrest of spontaneous contraction by either membrane depolarization or Ca2+ channel blockage did not interfere with the shift towards α-myosin heavy chain predominance. We conclude that thyroid regulation of myosin subunits is confined to the molecule heavy subunits and occurs irrespective of cell contraction. Furthermore, the genomic expression of creatine kinase is not regulated by thyroid hormone.
KW - Cell contractility
KW - Chemically defined medium
KW - Creatines kinase
KW - Cultured myocytes
KW - Myosin heavy chains
KW - Myosin light chains
KW - Triiodothyronine
UR - http://www.scopus.com/inward/record.url?scp=0023751525&partnerID=8YFLogxK
U2 - 10.1016/S0022-2828(88)80122-6
DO - 10.1016/S0022-2828(88)80122-6
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C2 - 3172251
AN - SCOPUS:0023751525
SN - 0022-2828
VL - 20
SP - 649
EP - 655
JO - Journal of Molecular and Cellular Cardiology
JF - Journal of Molecular and Cellular Cardiology
IS - 7
ER -