methylxanthine phosphodiesterase inhibitors ( mxpi ) , caffeine , theophylline , and 3-isobutyl-1-methylxanthine ( ibmx ) ( 0.3-5 mg/100 g body wt . ) similarly inhibited net 45ca uptake into femur and to a lesser extent calvarium .
C0039771
theophylline
C0000096
3-isobutyl-1-methylxanthine