The aim of the study was to elucidate the role of beta-adrenoceptors in normal human nasal mucosa. In two studies, beta-receptor function was tested by the application of agonists and antagonists. Measurements of nasal secretion and nasal peak expiratory flow were performed at 4-min intervals, during 12 min of rest, pre- and post-treatment, 12 min of exercise and 20 min of recovery. In Study 1, placebo was compared with 100 micrograms salbutamol and 2 mg propranolol. Neither placebo nor 100 mg salbutamol affected nasal secretion production at rest, but propranolol caused a transient significant increase (p < 0.05). Exercise significantly increased secretion production in all three treatment groups (p < 0.05). Nasal peak expiratory flow was not altered at rest, but increased significantly (p < 0.05) during exercise in the three treatment groups. In Study 2 placebo was compared with 200 mg salbutamol, 80 micrograms isoprenaline and 2 mg atenolol. Secretion production was not altered at rest by any treatment and increased during exercise in all four (p < 0.05). There was no significant difference between weights of secretions produced between any of the treatment groups during exercise. Salbutamol significantly decreased nasal peak expiratory flow at rest compared with placebo (p < 0.05). During exercise nasal peak flow increased in all groups, but peak exercise values were significantly reduced by both salbutamol and isoprenaline (p < 0.05). Atenolol appeared to have no effect on nasal peak expiratory flow.(ABSTRACT TRUNCATED AT 250 WORDS)