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ISSN 1672-9145 Acta Biochim Biophys Sin 2004, 36(12): 793–797 CN 31-1940/Q

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Changes in Autoantibodies against b₁-Adrenoceptor and M₂-Muscarinic Receptor during Development of Renovascular Hypertension in Rats

Jian-Ming ZHI^*, Rong-Fang CHEN¹, Heng WU², Hui-Rong LIU², and Rong-Rui ZHAO²

Department of Physiology, Shanghai Second Medical University, Shanghai 200025, China;

¹Department of Toxicology, Second Military Medical University, Shanghai 200433, China;

²Department of Physiology, Shanxi Medical University, Taiyuan 030001, China

Abstract In an experimental rat's renovascular hypertension model, we studied the genesis of anti-cardiac b₁-adrenoceptor and M₂-muscarinic receptor autoantibodies in relation to the changes in immunological function during the development of renal hypertension. The biological activities of these autoantibodies were also examined. It was shown that after two weeks of operation both the frequency of occurrence and the titre of autoantibodies to cardiac b₁-adrenoceptor and M₂-muscarinic receptor were significantly increased as compared with the control of pre-treatment. The increased autoantibodies lasted for several weeks and then automatically decreased gradually to the pre-clipping level at 10 weeks. Meanwhile the ratio of CD₄⁺/CD₈⁺ was also undergone an initial increase followed by gradual recovery and correlated well with the changes in antibody titre. The biological effects of these autoantibodies displayed an agonistic-like activities on the beating frequency of cultured neonatal cardiomyocyte. It is suggested that autoimmune mechanisms are involved in the pathogenesis of renal hypertension and the cardiac receptor autoantibodies might be one of the mechanisms leading to cardiac dysfunction.

Key words autoantibody; renal hypertension; cardiac receptor; immunology

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Received: June 9, 2004 Accepted: October 2, 2004

*Corresponding author: Tel, 86-21-63846590-776446; E-mail, [email protected]