Related Experiment Video
Updated: Oct 20, 2026

Primary Culture of Adult Rat Heart Myocytes
Published on: June 15, 2009
Alterations of subtypes of cardiac adrenoceptors in old rat
Aim:
To determine alterations of subtypes of myocardial adrenoceptors in senescence.
Methods:
Heart membrane preparations were made from 3- and 25-month old Wistar rats. Alpha 1- and beta-adrenoceptors were measured by radioligand, 125I-BE2254 and 125I-pindolol, binding assays, respectively.
Results:
In the old rat heart, alpha 1- and beta-adrenoceptor densities were declined from the young rats of 119 +/- 4 and 45.9 +/- 1.9 pmol L-1 to 70 +/- 6 and 36.4 +/- 1.6 pmol L-1 (P < 0.01), with a greater change in alpha 1-AR and in beta-AR. The ratio of alpha 1A/alpha 1B subtypes was decreased from the young rats of 39/61 to the old rats of 26/74 (P < 0.05).
Conclusion:
The cardiac adrenoceptors are decreased with different extents in the different subtypes in old rats.
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