CIRCULATING ANTIBODIES AGAINST NEONATAL CARDIAC MUSCARINIC ACETYLCHOLINE-RECEPTOR IN PATIENTS WITH SJOGRENS-SYNDROME

Citation
E. Borda et al., CIRCULATING ANTIBODIES AGAINST NEONATAL CARDIAC MUSCARINIC ACETYLCHOLINE-RECEPTOR IN PATIENTS WITH SJOGRENS-SYNDROME, Molecular and cellular biochemistry, 164, 1996, pp. 335-341
Citations number
40
Categorie Soggetti
Biology,"Cell Biology
ISSN journal
03008177
Volume
164
Year of publication
1996
Pages
335 - 341
Database
ISI
SICI code
0300-8177(1996)164:<335:CAANCM>2.0.ZU;2-5
Abstract
Isolated congenital heart block may be associated with Primary Sjogren 's Syndrome. In this work we demonstrated that IgG present in the sera of patients with Primary Sjogren's Syndrome (PSS) could bind and acti vate muscarinic acetylcholine receptors of rat neonatal atria. These a ntibodies were able to inhibit in a irreversible manner the binding of H-3-QNB to muscarinic cholinergic receptors of purified rat atria mem branes. Moreover, IgG from PSS individuals could modify biological eff ects mediated by muscarinic cholinoceptors activation, i.e. decrease c ontractility and cAMP and increase phosphoinositide turnover and cGMP. Atropine blocked all of these effects and carbachol mimicked them; co nfirming muscarinic cholinergic receptors-mediated PSS IgG action. Nei ther binding nor biological effect were obtained using adult instead o f neonatal rat atria. Ige from sera of normal women were not effective in the studied system. The prevalence of cholinergic antibody was 100 % in PSS and was independent of Ro/SS-A and La/SS-B antibodies. It cou ld be concluded that antibody against muscarinic cholinergic receptors may be another serum factor to be considered in the pathophysiology o f the development of congenital heart block.