Decreased expression of beta1- and beta2-adrenoceptors in human diabetic atrial appendage.
BACKGROUND
Using the streptozotocin-induced diabetic rat model, we have recently showed that the expression and function of beta1-adrenoreceptor were decreased in the diabetic rat heart. However, the effect of diabetes on expression of beta-adrenoreceptors in human cardiac tissue remains undefined. Therefore, the focus of the present study was to investigate the effect of diabetes on mRNA encoding beta1- and beta2-ARs in human atrial tissues.


METHODS
Right atrial appendages from five diabetic (mean age 65 +/- 4.5; 4 female, 1 male) and five nondiabetic patients (mean age 56.2 +/- 2.8; 4 male, 1 female) undergoing coronary artery bypass grafting were collected and assayed using reverse transcriptase-polymerase chain reaction (RT-PCR) for their mRNA content. No patient from these two groups suffered from acute myocardial infarction and/or failure. All diabetic patients received insulin for at least two years and had been diagnosed as diabetics for at least five years.


RESULTS
When compared with levels in nondiabetics, steady state levels of mRNA encoding beta1-adrenoreceptor decreased by 69.2 +/- 7.6% in diabetic patients while beta2-adrenoreceptor mRNA decreased by 32.2 +/- 5.5% (p < 0.001).


CONCLUSIONS
Our findings show a decreased expression of beta1- and beta2-adrenoreceptors in human diabetic atrial appendage.
Dinçer
U Deniz
UD
Department of Pharmacology, Faculty of Pharmacy, University of Ankara, Ankara, Turkey. dincer@pharmacy.ankara.edu.tr
Güner
Sahika
S
Tay
Aydin
A
Arioğlu
Ebru
E
Taşdelen
Atilay
A
Aşlamaci
Sait
S
Bidasee
Keshore R
KR