From the Institute of Biochemistry and Biophysics, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran.
Abstract: (3972 Views)
The effect of theophylline on colony stimulating factor production by
the lung tissue was investigated. Addition of various concentrations of
theophylline to the lung conditioned medium enhanced CSF production at
10 µg/ml and at higher concentrations showed an inhibitory effect. Determination
of the phosphate content of the medium showed a decrease at 1-3
hours of incubation. Addition of AMP to the cultures in the presence of
theophylline had no effect on the CSF production but compensated phosphate
content of the lung cultures. Exogenous cAMP or its dibutyryl
derivative also stimulated CSF production. On the other hand IBMX,
another inhibitor of phosphodiesterases, exerted similar effect as theophylline.
The results suggest that cAMP regulates CSF production by the lung.