The increase in vivo by electric currents of the 99mTc-methylene diphosphonate uptake and cyclic AMP content of the bone of the cat mandible

Abstract Technetium-99-methylene diphosphonate ( 99 m Tc-MDP) bone images were obtained from live cats whose mandibles had been stimulated non-invasively and unilaterally with electric current (12 ± 2 μA ) for 1 week. The images were obtained using a gamma camera interfaced to a digital computer for quantitative comparison of the mandible. Radionuclide uptake by the stimulated sides increased by 59 ± 26 per cent when compared with the contralateral control sites. Immunohistochemical staining of mandibular sections for adenosine 3′,5′-monophosphate (cyclic AMP) showed that periosteal osteoblasts opposite the electrodes were intensely stained. Thus 99 m Tc-MDP scintigraphy is a sensitive non-invasive technique for determining in vivo enhanced bone remodelling activity. The immunohistochemistry indicates that the stimulation of bone cells was limited to surfaces adjacent to both cathode and anode.