Abstract 5819: Long-term Existence of the Autoantibodies Against the Second Extracellular Loop of {beta}1-Adrenoceptor Induces Kidney Injury in Rats

Background: The effects of antibodies against the second extracellular loop (EC II ) of β 1 -adrenoceptors ( β 1 -AA) have been extensive investigated in cardiovascular disease. Our previous study has demonstrated that peritoneal exudate had been induced after long-term active immunization with synthetic peptides corresponding to human β 1 -AR-EC II in rats. We hypothesis that β 1 -AA may also bind with β 1 -AR in kidney and display pathophysiological roles. Methods: Immunization models were set up using either the peptides corresponding to the EC II of β 1 -adrenoceptors or β 1 -AA in Rats; the long-term effects of anti- β 1 -AR-EC II on kidney structure and function were observed. Results: Compared with the vehicle group, blood urea nitrogen (BUN), creatinine (CR), and uric acid (UA) increased, and the BUN-to-CR ratio decreased markedly at the 8 th week after immunization with peptides (BUN: 8.9±0.95 mM vs 6.7±0.35 mM, P vs 40.9±1.38 mM, P vs 89.5±9.80 mM, P vs 0.16±0.008, P th week after immunization, BUN and CR were still higher than those in the vehicle group ( P P P β 1 -AA was used to confirm the above results. BUN, CR, UA significantly increased, and BUN/CR decreased as comparing with the negative sera group at 24 th week after immunization (BUN: 9.25±0.43 mM vs 6.56±0.28 mM; CR: 68.8±8.05 mM vs 41.8±1.39 mM; UA: 166.5±21.14 mM vs 86.3±12.35 mM; BUN/CR: 0.14±0.009 vs 0.16±0.006; all P Conclusion: Anti- β 1 -AA could lead impairment of kidney function and structure, suggesting that anti- β 1 -AA may have a broad spectrum of organ injury effect in addition to its reported harmful effects in cardiovascular system.