A Study of the Plasma Level of Cyclic Nucleotides in Bronchial Asthmatics

Abstract

The plasma levels of cyclic adenosine 3',5'-monophosphate (cAMP) and cyclic guanosine 3',5'-mono phosphate (cGMP) and the serum level of aminophylline were measured in bronchial asthmatics. Their ages ranged from 5 years to 89 years and durations of symptom from 3 months to 30 years. Blood samplings were taken between 10:00 AM and 12:00 MD. 1. In bronchia! asthmatics, the mean plasma level of cAMP was 9. 7±7. 1 pmol/ml(mean±S.D., l pmol/ ml to 38pmol/ml) and was significantly higher than that of norma! adults (p<O.01). The mean plasma level of cGMP was 3. 9±1. 7 pmol/ml (mean±S.D., 0.5 pmol/ml to 9.2 pmol/ml) and was not significantly different from normal adults. 2. In bronchial asthmatics without wheezing whose serum levels of aminophylline were not detected, the mean plasma levels of cAMP and cGMP were 8.9± 7.8 pmol/ml and 3. 7±2. 0 pmol/ml respectively. In bronchial asthmatics with wheezing whose serum levels of aminophylline were not detected, the mean plasma levels of cAMP and cGMP were 7. 7±5. 7 pmol/ml and 4.4::1.2.0 prnol/rnl (mean ±S.D.) respectively. There was no significant difference between bronchial asthmatics with wheezing and those without wheezing. 3. In bronchial asthmatics whose serum levels of aminophylline were higher than 2.5pg/ml, the mean plasma level of cAMP was significantly higher than bronchial asthmatics whose serum levels of aminophylline were not detected (p<O.OI). But the mean plasma level of cGMP was not different significa· ntly (p>0.05). 4. There was no correlation between the serum level of aminophylline and the plasma levels of cAMP and cGMP