Comparison of the effects of theophylline, prednisolone and sleep withdrawal on airway obstruction and urinary cyclic AMP/cyclic GMP excretion of asthmatic children with and without nocturnal asthma.

Asthmatic children suffering from nocturnal asthmatic paroxysms showed not only a reduced peak exspiratory flow rate (PEER) but also a diminished excretion of cyclic AMP (cAMP) at night. In contrast, in asthmatic children without nocturnal asthmatic attacks, neither in PEFR nor in cAMP excretion did a circadian rhythm occur. Prednisolone, theophylline, and sleep withdrawal were able to reestablish normal airway function and cAMP excretion in those patients with nocturnal bronchoconstriction. Cyclic GMP (cGMP), which has been suggested as a mediator for cholinergic mechanisms, shows the exact opposite behavior of that of cAMP. In children suffering from nocturnal asthmatic attacks, cGMP increases during the night, whereas under sleep withdrawal it decreases. Hence we propose that a reduced responsiveness of beta-adrenergic receptors as well as an increased cholinergic activity are due to nocturnal asthmatic attacks. Therapeutic interventions taking the form of increasing cAMP or decreasing cGMP levels may thus be most helpful in treating nocturnal asthma.