The Sound of Evolution
Theophylline
Mechanism of action:
Theophylline is a methylxanthine compound. Theophylline inhibits intracellular phosphodiesterase, especially PDE3 and PDE4, thereby reducing the breakdown of cAMP and increasing its concentration. Elevated cAMP activates protein kinase A, leading to relaxation of bronchial smooth muscle. Theophylline also antagonizes adenosine receptor A₁ and A₂A, reducing bronchoconstriction and enhancing respiratory center excitability.
Reference(s):
1. Nantwi KD et al. (2003). Adenosine A1 receptor mRNA expression and the effects of systemic theophylline administration on respiratory function 4 months after C2 hemisection. J Spinal Cord Med.
2. Daly JW et al. (1987). Adenosine receptors: development of selective agonists and antagonists. Prog Clin Biol Res.
3. Abdelrahman A et al. (2020). Substituted 4-phenylthiazoles: Development of potent and selective A(1), A(3) and dual A(1)/A(3) adenosine receptor antagonists. Eur J Med Chem.