Further studies on the effect of ageing on beta-adrenoceptor activity of rat aorta

beta-Adrenoceptor activity of rat thoracic aorta decreased with the increasing age of the animal. The ability of aortas to relax to isoprenaline was completely lost when rats were 3-6 months old, depending on the source and strain of animals. NaNO(2), however, completely relaxed aortic tissue from animals of all ages tested.