Plasma @entity2661 and haemodynamic responses to isometric handgrip, orthostatic body position and dynamic cycle exercise were studied in 10 healthy old @entity1 (mean age 71 years) and 10 healthy young @entity1 (mean age 26 years). At rest, plasma @entity1063 (NA) was significantly higher in the old age group. During handgrip there were greater increases in heart rate and blood-pressure in the young rather than in the old @entity1 , while forearm blood-flow increase was similar in the two age groups, and there was no increase in NA in either groups. In the orthostatic position heart rate increased in the young @entity1 only, and forearm blood-flow decreased more in the young than in the old @entity1 . NA concentration increased similarly in both age groups. During dynamic exercise the increases in both the heart rate and the blood-pressure, at similar relative submaximal as well as maximal loads, were smaller in the old @entity1 . At maximal work NA and @entity1425 (A) concentrations were higher in the young @entity1 , while at the lowest load, NA concentration was higher in the old @entity1 . Similar increases in exercise heart rate, blood-pressure or rate of perceived exertion corresponded to lower increases in NA in the old @entity1 . It can be concluded that old @entity1 , compared with young @entity1 , have a reduced maximal capacity to release NA and A upon provocation. In addition, the sensitivity for @entity2661 in the target organ is reduced with age, as suggested by the smaller increases in heart rate and blood-pressure for a given increase in NA during exercise. The higher basal NA level and the higher NA level, during moderate provocation, may suggest a compensatory increase in activity.

Cardiovascular responses and plasma XXXX in old age.

@entity1 :: ('9606', 'Species') :: ['men'] @entity1425 :: ('MESH:D004837', 'Chemical') :: ['adrenaline'] @entity2661 :: ('MESH:D002395', 'Chemical') :: ['catecholamines'] @entity1063 :: ('MESH:D009638', 'Chemical') :: ['noradrenaline']
@entity2661 :: (MESH:D002395,Chemical) :: ['catecholamines']
