Abstract
In this study, we observed serum theophylline concentration, clincal symptoms and signs, plasma cyclic AMP (c-AMP) and cyclic GMP (c-GMP) in asthmatic patients. 10 normal subjects and 24 asthmatics were studied for cyclic nucleotides. 5 normal subjects and 15 asthmatics were studied for serum theophylline concentration, respiratory resistance and cyclic nucleotides by concentrated intravenous infusion of 250mg Neophyllin in 500ml 5 % glucose in 2 hr. Serum theophylline concentrations were determined by i-PiT system, and plasma cyclic nucleotide concentrations were determined by RIA, according to the method of Steiner et al. Respiratory resistance and clincal symptoms in 6 asthmatics decreased and finally disappeared, as established by changes in serum theophylline concentration. Clinical condition of high dose group improved more remarkable than that of low dose group in the range of effective serum theophylline concentration. There were no significant differences between asthmatic-attacked, non-attacked and normal subjects in the plasma cyclic nucleotide consentration before the administration of theophylline. The ratio of c-AMP to c-GMP (A/G) similarly showed no significant differences. In asthmatic-attacked and normal subjects, plasma c-AMP concentration decreased in 1 hr, compared with the concentration before the administration of theophylline and was increased for the entire time. In non-attacked subjects, it increased with time. These results suggested that cyclic nucleotides in these three groups showed different concentrations with time.
