The integrity of the noradrenergic innervation of the cardiovascular system in genetically dystrophic hamsters.

Noradrenergic nerves in dystrophic hamsters did not differ, in fluorescence morphology, from those in control hamsters. The responses to noradrenergic nerve stimulation and the sensitivity to noradrenaline of right atria and hepatic portal veins were similar in control and dystrophic animals. The contractility of left atria and their maximal responses to noradrenaline or noradrenergic nerve stimulation at 4 Hz were depressed relative to control. This reduction in inotropic responsiveness may be due to disturbances of excitation-contraction coupling.