caa a22 4500 477120695 CHVBK 20180405111636.0 cr unu---uuuuu 170330e19960301xx s 000 0 eng 10.1007/BF00408646 doi (NATIONALLICENCE)springer-10.1007/BF00408646 Antibodies from Trypanosoma cruzi infected mice recognize the second extracellular loop of the β1-adrenergic and M2-muscarinic receptors and regulate calcium channels in isolated cardiomyocytes [Elektronische Daten] [Alfredo Mijares, Ludovic Verdot, Nicolas Peineau, Bernard Vray, Johan Hoebeke, Jorge Argibay] Sera from T. cruzi infected mice were tested in an enzyme immunoassay on peptides corresponding to the second extracellular loops of the β−, the β2-adrenergic receptor and the M2 muscarinic receptor. All sera of mice (4/4) in the acute phase recognized the β1-adrenergic receptor and the M2 muscarinic receptor peptides but not the β2-adrenergic receptor peptide. The same peptides were recognized during the chronic phase in half of the mice (6/12). The immunoglobulin fractions of the mice were tested for their activity on L-type Ca−+ channels of isolated guinea-pig cardiomyocytes using the whole-cell patch clamp technique. The immunoglobulin fractions of acute phase mice were able to activate the Ca−+ channels by stimulation of the β-adrenergic receptors, as assessed by inhibition with propranolol. Those of the chronic phase mice reduced the Ca++ current by stimulation of the muscarinic receptors, as assessed by inhibition with atropine. These results confirm the existence of functional epitopes on the second extracellular loops of both receptors. They suggest that, as in humans, the parasite is able to elicit functional autoantibodies against these epitopes. They give evidence that these autoantibodies mediate their physiological effects by modulating the cAMP activated Ca+− channels. Kluwer Academic Publishers, 1996 Chagas' disease nationallicence antibodies nationallicence adrenergic nationallicence muscarinic nationallicence receptor nationallicence calcium channel nationallicence Trypanosoma cruzi nationallicence Mijares Alfredo Laboratoire de Physiologie des Cellules Cardiaques et Vasculaires Faculte de Sciences Tours, France aut Verdot Ludovic Equipe d'Immunologie des Récepteurs, CJF 93/09 Immunologie des Maladies Infectieuses, Faculte de Pharmacie Tours, France aut Peineau Nicolas Laboratoire de Physiologie des Cellules Cardiaques et Vasculaires Faculte de Sciences Tours, France aut Vray Bernard Laboratoire d'IImmunologie Expérimentale, Faculte de Médecine, CP61 S Université Libre de Bruxelles, Brussels, Belgium aut Hoebeke Johan Equipe d'Immunologie des Récepteurs, CJF 93/09 Immunologie des Maladies Infectieuses, Faculte de Pharmacie Tours, France aut Argibay Jorge Laboratoire de Physiologie des Cellules Cardiaques et Vasculaires Faculte de Sciences Tours, France aut Molecular and Cellular Biochemistry Kluwer Academic Publishers; http://www.wkap.nl 163-164/1(1996-03-01), 107-112 0300-8177 163-164:1<107 1996 163-164 11010 https://doi.org/10.1007/BF00408646 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00408646 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Mijares Alfredo Laboratoire de Physiologie des Cellules Cardiaques et Vasculaires Faculte de Sciences Tours, France aut NATIONALLICENCE 700 1- Verdot Ludovic Equipe d'Immunologie des Récepteurs, CJF 93/09 Immunologie des Maladies Infectieuses, Faculte de Pharmacie Tours, France aut NATIONALLICENCE 700 1- Peineau Nicolas Laboratoire de Physiologie des Cellules Cardiaques et Vasculaires Faculte de Sciences Tours, France aut NATIONALLICENCE 700 1- Vray Bernard Laboratoire d'IImmunologie Expérimentale, Faculte de Médecine, CP61 S Université Libre de Bruxelles, Brussels, Belgium aut NATIONALLICENCE 700 1- Hoebeke Johan Equipe d'Immunologie des Récepteurs, CJF 93/09 Immunologie des Maladies Infectieuses, Faculte de Pharmacie Tours, France aut NATIONALLICENCE 700 1- Argibay Jorge Laboratoire de Physiologie des Cellules Cardiaques et Vasculaires Faculte de Sciences Tours, France aut NATIONALLICENCE 773 0- Molecular and Cellular Biochemistry Kluwer Academic Publishers; http://www.wkap.nl 163-164/1(1996-03-01), 107-112 0300-8177 163-164:1<107 1996 163-164 11010 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer