Figure 4. The influence of ageing on increases in (top to bottom) adrenaline secretion and the spillover of noradrenaline to plasma from the whole body and from the heart during the application of laboratory stress.

The increases in total noradrenaline spillover rates with the stimuli were not affected by ageing. Contrasting effects of ageing were observed for stimulation of adrenaline secretion (lower in older men) and cardiac noradrenaline spillover (higher in older men). Reprinted (from Esler et al. 1995a) with permission. *P < 0·05 and **P < 0·01 indicate significance of differences between younger and older men. Mean ±s.e.m. values are shown.