Mechanisms of denervation supersensitivity in regionally denervated canine hearts

Mechanisms responsible for denervation supersensitivity in regionally denervated canine hearts were examined by measuring beta-adrenergic receptor density and affinity and the density of the alpha-subunit of the stimulatory guanine nucleotide binding protein (Gi alpha). Results suggest that an alteration distal to the beta-adrenergic receptor, but not involving an increase in the density of Gi alpha, potentiates adrenergic signal transduction in dernervated areas of regionally denervated canine hearts.