Sarcolipin, a homologue of phospholamban, regulates Ca2+ uptake through the 
interaction with sarcoplasmic reticulum Ca2+ ATPase (SERCA) and is predominantly 
expressed in the atrial muscle. Although the atrial chamber-specific expression 
of sarcolipin could be primarily regulated at the transcriptional level, the 
transcriptional regulation remains poorly understood. Since mechanical stress 
plays an important role in transcriptional regulation of a gene involved in 
cardiac hypertrophy and remodeling, we generated left-sided or right-sided 
pressure-overload models by transverse aortic constriction (TAC) in ddY mice or 
by monocrotaline administration in Wistar rats, respectively. TAC significantly 
decreased the expression of sarcolipin, SERCA2a, and phospholamban mRNAs in the 
left atrium (LA) than those in the right atrium (RA). By contrast, monocrotaline 
administration significantly decreased the expression of sarcolipin, SERCA2a, 
and phospholamban mRNAs in the RA than those in the LA. The two independent 
complementary experiments unequivocally demonstrated that mechanical stress 
down-regulates the transcription of the sarcolipin gene.