Propranolol and verapamil inhibit mRNA expression of RyR2 and SERCA in L-thyroxin-induced rat ventricular hypertrophy.
OBJECTIVE
To study the alteration in the mRNA level of cardiac ryanodine receptor 2 (RyR2) and sarco-endoplasmic reticulum Ca2+-ATPase (SERCA) in L-thyroxin-induced hypertrophy.


METHODS
L-thyroxin (500 g/kg) daily was injected for 10 d. RT-PCR was used to determine mRNA expression.


RESULTS
An increase in the relative amount of RyR2 (111 %) and SERCA mRNA (65 %) expression was observed in the hypertrophied rats (RyR2: 77+/-11; SERCA: 87+/-10, n=9) compared with the normal rats (RyR2: 36+/-10; SERCA: 53+/-10, n=9). Propranolol was effective to inhibit the increase in RyR2 (51+/-7) and SERCA (63+/-13) mRNA expression in hypertrophied rats, respectively. Verapamil also reduced RyR2 (62+/-5) and SERCA (75+/-8) mRNA expression.


CONCLUSIONS
Both RyR2 and SERCA mRNA level in L-thyroxin-induced cardiac hypertrophy was over-expressed and propranolol or verapamil inhibited the alteration.
Research Division of Pharmacology, China Pharmaceutical University, Nanjing 210009, China.
Xiao-dong
XD
Wu
De-zai
DZ
Dai
Qiu-pin
QP
Zhang
Feng
F
Gao
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D000252:Calcium-Transporting ATPases / Q000096:biosynthesis* / Q000235:genetics; D006332:Cardiomegaly / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism*; D005260:Female; D008297:Male; D009206:Myocardium / Q000378:metabolism; D011433:Propranolol / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D011897:Random Allocation; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019837:Ryanodine Receptor Calcium Release Channel / Q000096:biosynthesis* / Q000235:genetics; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D013974:Thyroxine; D014700:Verapamil / Q000494:pharmacology*
D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D002121:Calcium Channel Blockers; D012333:RNA, Messenger; D019837:Ryanodine Receptor Calcium Release Channel; D011433:Propranolol; D014700:Verapamil; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D000252:Calcium-Transporting ATPases; D013974:Thyroxine