Elevated plasma concentration of neuropeptide Y and low level of circulating adrenaline in elderly asthmatics during rest and acute severe asthma.

Twenty-five elderly asthmatic patients attending the internal medicine emergency ward because of an acute exacerbation of asthma were sampled, prior to acute treatment, for determination of systemic venous plasma levels of noradrenaline (NA), adrenaline (A) and neuropeptide Y-like immunoreactivity (NPY-LI). Whereas NA and NPY-LI were about two-fold higher than control values, plasma A levels were not significantly increased. Twelve of the asthmatic patients were also tested at resting stable conditions and were essentially asymptomatic. All values were then similar to those of control subjects (n = 28) except for a significantly higher NPY-LI plasma level in asthmatics. In seven of these patients a near maximal physical exercise test caused significantly increased NA, A and NPY-LI plasma levels. It is concluded that the acute asthma attack is associated with elevated NA and NPY-LI plasma levels, but an impaired A response. Furthermore, that circulating NPY under these conditions has a nervous rather than adrenal origin.