[Determination of beta-adrenergic binding sites in the myocardium of young female chickens of various strains--a study for the clarification of frequent occurrence of sudden death and ascites in male broilers].

The present investigations should contribute to clarify the importance of beta-adrenergic system in myocard for the triggering of sudden death syndrome and ascites in male broiler chickens. Therefore it should be verified if differences in density of beta-adrenergic receptors in myocard exist in several strains and sexes of chickens. We showed in both male and female broilers that the receptor density was significantly higher as in chickens of the laying strain. There were no significant differences in receptor density between sexes in both investigated strains as well as in KD-values between all groups. The latter finding is referred to the absence of differences in receptor affinity for 3H-dihydroalprenolol between the groups. Clarification of the question if chronic heart failure is in contrast to myocard hypertrophy accompanied with reduction of beta-adrenergic receptor density or receptor affinity in broilers too, as could be shown in other species, has to carried out in further investigations.