Myocardial β‐adrenergic receptor characteristics in T3‐induced ascites and in broiler lines differing in ascites susceptibility

Open Access
Publisher Website
Google Scholar
Abstract
The present study was designed to investigate the myocardial β‐adrenergic receptor characteristics in T3‐induced ascites in two genetic lines of broilers, in order to look for possible involvement of myocardial β‐adrenergic receptors in the development of broiler ascites syndrome. Myocardial membrane fractions were prepared from 6 and 8 week old chickens fed a 1.5 parts/106 T3 supplemented diet from day 1 in order to increase ascites incidence. Also, a similar assay was performed on myocardial cells of ascites sensitive and ascites resistant chickens at 5 weeks of age. The binding capacity and binding affinity of the myocardial β‐adrenergic receptor of the two genetic lines of birds did not differ significantly, but the tendency of β‐adrenergic receptor binding capacity and affinity constants in ascites‐sensitive birds was slightly higher compared to ascites‐resistant birds. In commercial broilers, although dietary T3 significantly increased ascites mortality and the RV/TV ratio compared to control, it did not affect significantly β‐adrenergic receptor characteristics.