Animal Sciences Commons^™

The Effects Of Xanthine And Adenosine Analogs On Rat Pup Diaphragmatic Contractility, Liam C. Farrell

Masters Theses

Methylxanthines are commonly used in the treatment of respiratory disorders such as asthma, apnea of prematurity and Cheyne-Stokes respiration. Recently, certain methylxanthines have been found to potentiate the contraction of the diaphragm and increase contraction strength of the fatigued diaphragm. The mechanism of action of the methylxanthines is unknown. Three theories have been proposed but each has its supportive and negative points. One theory is that methylxanthines inhibit cyclic AMP phosphodiesterase (PDE) which facilitates contraction by increasing cyclic AMP levels in the cell. Another theory is that methylxanthines antagonize adenosine, thus blocking the adenosine-induced inhibition of contraction. The third theory …