Effect of estrogen on calcium-handling proteins, beta-adrenergic receptors, and function in rat heart. Life Sci 2006 Aug 22;79(13):1257-67
Date
05/02/2006Pubmed ID
16647722DOI
10.1016/j.lfs.2006.03.037Scopus ID
2-s2.0-33746912380 (requires institutional sign-in at Scopus site) 82 CitationsAbstract
Regulation of cellular Ca(2+) cycling is central to myocardial contractile function. Loss of Ca(2+) regulation is associated with cardiac dysfunction and pathology. Estrogen has been shown to modify contractile function and to confer cardioprotection. Therefore, we investigated the effect of estrogen on expression of rat heart myocardial Ca(2+)-handling proteins and beta-adrenergic receptor (beta(1)-AR) and examined functional correlates. Female rats were sham-operated (SHAM) or ovariectomized. Two weeks after ovariectomy rats were injected (i.p.) daily with estradiol benozoate (OVX+EB) or sesame oil (OVX) for 2 weeks. Protein abundance was measured by immunoblotting and mRNA was quantified by real-time RT-PCR. OVX significantly decreased estrogen and progesterone levels and EB replacement returned both estrogen and progesterone to physiological levels. OVX induced a 75% reduction of uterine weight and a gain in body weight. Replacement restored weights to SHAM level. OVX increased and estrogen-replacement normalized abundance of beta(1)-AR and L-type Ca(2+) channel (Cav1.2) protein. OVX decreased sodium-Ca(2+) exchange protein (NCX) and estrogen restored protein abundance to SHAM levels. Sarcoplasmic reticular ATPase (SERCA), phospholamban (PLB), and ryanodine receptor (RyR) abundance was not altered by hormone status. Levels of mRNA encoding for beta(1)-AR, Cav1.2, and NCX were not influenced by OVX or estrogen replacement. OVX had no effect on SERCA and PLB mRNA level but estrogen replacement elicited a significant increase compared to OVX and SHAM. Estrogen-dependent changes in Ca(2+)-handling proteins and beta(1)-AR are theoretically consistent reduced myocellular Ca(2+) load. However, hormone-dependent alterations in protein were not associated with changes in contractile function.
Author List
Chu SH, Goldspink P, Kowalski J, Beck J, Schwertz DWMESH terms used to index this publication - Major topics in bold
AnimalsCalcium
Calcium Channels, L-Type
Calcium-Binding Proteins
Estrogen Replacement Therapy
Estrogens
Female
Heart
Heart Ventricles
Homeostasis
Membrane Proteins
Muscle Proteins
Myocardial Contraction
Organ Size
Ovariectomy
Papillary Muscles
RNA, Messenger
Rats
Rats, Sprague-Dawley
Receptors, Adrenergic, beta
Sodium-Calcium Exchanger
