title: Thyroid hormone regulates Ca(2+)-ATPase mRNA levels of sarcoplasmic reticulum during neonatal development of fast skeletal muscle.
abstract: In gastrocnemius muscle from newborn rats the mRNA for the fast sarcoplasmic reticulum (SR) Ca(2+)-ATPase isoform (SERCA1) comprised over 90% of total SR Ca(2+)-ATPase mRNA content and increased 5-fold between day 5 and 20 after birth, whereas in hypothyroid muscle the SERCA1 message level remained constant. Triiodothyronine (T3) treatment of 2-day-old euthyroid rats induced a precocious stimulation of SERCA1 mRNA levels, indicating that T3 is the determining factor in the stimulation of SERCA1 message levels and that this stimulation underlies the previously reported effect of the thyroid status on the neonatal development of SR Ca(2+)-ATPase activity. The low mRNA level for the slow SR Ca(2+)-ATPase isoform (SERCA2) was constant in both euthyroid and hypothyroid muscle development. Nevertheless, T3 treatment of hypothyroid neonates induced a transient stimulation of SERCA2 message levels, indicating that SERCA2 is responsive to higher levels of T3.
authors.affiliation: Laboratory for Physiology, Free University, Amsterdam, Netherlands.
authors.forename: G C
authors.initials: GC
authors.lastname: van der Linden
authors.forename: W S
authors.initials: WS
authors.lastname: Simonides
authors.forename: C
authors.initials: C
authors.lastname: van Hardeveld
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000096:biosynthesis* / Q000235:genetics; D004790:Enzyme Induction / Q000187:drug effects; D005260:Female; D007037:Hypothyroidism / Q000378:metabolism; D007527:Isoenzymes / Q000096:biosynthesis* / Q000235:genetics; D024510:Muscle Development; D009124:Muscle Proteins / Q000096:biosynthesis* / Q000235:genetics; D009132:Muscles / Q000201:enzymology*; D011247:Pregnancy; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000201:enzymology*; D013963:Thyroid Hormones / Q000502:physiology*; D014284:Triiodothyronine / Q000494:pharmacology
chemical_list: D007527:Isoenzymes; D009124:Muscle Proteins; D012333:RNA, Messenger; D013963:Thyroid Hormones; D014284:Triiodothyronine; D000252:Calcium-Transporting ATPases