The frequencies of anti-β₃-autoantibodies in non-BRL and BRL groups of aged rats with heart failure.

<p>2 mL of blood samples were collected before treatment, and at the 5^th, 6^th,7^th, 8^th,9^th, 10^th and 11^th week after treatment. The sera were separated by centrifugation (3000 rpm, Beckman CS-15R Centrifuge) for 10 min and stored at −80°C until needed for assay. Anti-β₃-AR autoantibody was determined by enzyme-linked immunosorbent assays (ELISA). The frequencies of anti-β₃-autoantibodies in the BRL group increased markedly at the 5^th week, and reached a maximum at the 10^th week in both BRL group and non-BRL group. The frequencies of anti-β₃-autoantibodies were significantly higher in BRL group than non-BRL group and Sham group (*<i>p</i><0.05). BRL group: HF group with β₃-AR agonist of BRL37344 injection; non-BRL group: HF group without BRL37344 injection.