Cardiac beta-receptors in experimental Chagas' disease.
Experimental Chagas' disease (45 to 90 days post-infection) showed serious cardiac alterations in the contractility and in the pharmacological response to beta adrenergic receptors in normal and T. cruzi infected mice (post-acute phase). Chagasic infection did not change the beta receptors density (78.591 +/- 3.125 fmol/mg protein and 73.647 +/- 2.194 fmol/mg protein for controls) but their affinity was significantly diminished (Kd = 7.299 +/- 0.426 significantly diminished (Kd = 7.299 +/- 0.426 nM and Kd = 3.759 +/- 0.212 nM for the control) p < 0.001. This results demonstrate that the alterations in pharmacological response previously reported in chagasic myocardium are related to a significantly less beta cardiac receptor affinity. During this experimental period serious cardiac cell alterations take place and functional consequences will be detected in the chronic phase.
Enders
J E
JE
Cátedra de Física Biomédica, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Argentina.
Paglini
P
P
Fernandez
A R
AR
Marco
F
F
Palma
J A
JA
D000319:Adrenergic beta-Antagonists / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D014355:Chagas Disease / Q000503:physiopathology*; D004082:Dihydroalprenolol / Q000378:metabolism; D006352:Heart Ventricles / Q000503:physiopathology; D051379:Mice; D009200:Myocardial Contraction / Q000187:drug effects*; D011943:Receptors, Adrenergic, beta / Q000032:analysis / Q000378:metabolism* / Q000502:physiology
D000319:Adrenergic beta-Antagonists; D011943:Receptors, Adrenergic, beta; D004082:Dihydroalprenolol