[Catecholamine secretory capacity in patients with bronchial asthma--influence of severity and glucocorticoid use]

Sympatho-adrenal dysfunction has been proposed as a factor related to bronchial hyperreactivity. However, humoral factors, which stimulate beta adrenoceptors, have not been evaluated sufficiently. The aim of this study was to evaluate the secretory capacity of catecholamine (CA) in patients with bronchial asthma. We carried out an insulin tolerance test on 24 asthmatics (mild: 8, moderate: 9, severe: 8) and 8 healthy volunteers. Plasma adrenaline (AD), noradrenaline (NA) and dopamine (DO) were measured by the enzymic isotope method. The following results were obtained: 1) There was no difference in plasma NA and DO between the asthmatics and and healthy controls. 2) With regard to plasma AD, the mild asthmatics showed a normal response, whereas the severe asthmatics showed a significantly low response. This low AD response was also confirmed in non-asthmatics using steroids continuously. Decreased AD response was therefore shown to be due to hypoadrenocortical function. 3) The asthmatics whose attacks suddenly grew worse showed an obviously decreased plasma AD response. These results suggest that there is no natural dysfunction of CA secretion in patients with bronchial asthma. However, these results imply that continuous steroid use induces low AD secretion, and that steroid-dependent asthmatics have a decreased productive capacity against sudden asthmatic attack.