Thyroid hormone differentially affects mRNA levels of Ca-ATPase isozymes of sarcoplasmic reticulum in fast and slow skeletal muscle.
mRNA levels for the type I and type II isoforms of sarcoplasmic reticulum (SR) Ca-ATPase were determined in soleus (SOL) and extensor digitorum longus (EDL) muscle of euthyroid (normal), hypothyroid, and hyperthyroid rats. Total Ca-ATPase mRNA content of hyperthyroid muscle was 1.5-fold (EDL) and 6-fold (SOL) higher compared to hypothyroid muscle, with corresponding increases in total SR Ca-ATPase activity. EDL contained only type II Ca-ATPase mRNA. In SOL type I mRNA was the major form in hypothyroidism (98%), but the type II mRNA content was stimulated 150-fold by T3, accounting for 50% of the Ca-ATPase mRNA in hyperthyroidism.
Simonides
W S
WS
Laboratory for Physiology, Free University, Amsterdam, The Netherlands.
van der Linden
G C
GC
van Hardeveld
C
C
D000818:Animals; D000252:Calcium-Transporting ATPases / Q000235:genetics* / Q000378:metabolism; D006980:Hyperthyroidism / Q000201:enzymology; D007037:Hypothyroidism / Q000201:enzymology; D007527:Isoenzymes / Q000235:genetics* / Q000378:metabolism; D008297:Male; D009132:Muscles / Q000187:drug effects / Q000201:enzymology*; D009928:Organ Specificity; D012333:RNA, Messenger / Q000235:genetics*; D051381:Rats; D011919:Rats, Inbred Strains; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000201:enzymology*; D013961:Thyroid Gland / Q000502:physiology*; D014284:Triiodothyronine / Q000494:pharmacology
D007527:Isoenzymes; D012333:RNA, Messenger; D014284:Triiodothyronine; D000252:Calcium-Transporting ATPases