Sympathotropic drugs and the distribution of 99mTc-hydroxymethylene diphosphonate. Experimental studies in the mouse.
OBJECTIVE
The uptake of bone-seeking radiopharmaceuticals depends on the blood flow, which is influenced by the sympathetic nervous system. Our aim was to study the effect of sympathomimetic drugs on the distribution of bone-seeking agents.


METHODS
Various sympathomimetic and beta-blocking drugs were injected in mice at different times in relation to the administration of 99mTc-HDP. Three hours after this, venous blood and various organs were removed and their activities were related to the administered activity. A kinetic study of the whole-body activity retention after administration of terbutaline was also made.


RESULTS
The biodistribution of 99mTc-HDP was similar after the administration of sympathomimetics and of beta-antagonists. All drugs gave rise to an increased soft tissue activity and a decreased bone activity, corresponding to a lowered quality of the potential bone scan. Terbutaline gave rise to an increased excretion of 99mTc-HDP. The mechanisms behind the findings cannot be entirely explained.


CONCLUSIONS
Drug interference with the sympathetic nervous system causes undesirable effects on the biodistribution of 99mTc-HDP in the mouse. Studies in humans are necessary to evaluate whether clinical treatment with sympathotropic drugs affects the bone scintigram.
Cronhjort
M
M
Department of Diagnostic Radiology, Karolinska Hospital, Stockholm, Sweden.
Jonsson
C
C
Jacobsson
H
H
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000378:metabolism; D003287:Contrast Media / Q000493:pharmacokinetics*; D004809:Ephedrine / Q000494:pharmacology; D008297:Male; D008790:Metoprolol / Q000494:pharmacology; D051379:Mice; D008815:Mice, Inbred Strains; D011433:Propranolol / Q000494:pharmacology; D011877:Radionuclide Imaging; D013015:Sotalol / Q000494:pharmacology; D013566:Sympathomimetics / Q000494:pharmacology*; D013669:Technetium Tc 99m Medronate / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D013726:Terbutaline / Q000494:pharmacology; D014018:Tissue Distribution
D000319:Adrenergic beta-Antagonists; D003287:Contrast Media; D013566:Sympathomimetics; C024226:technetium Tc 99m hydroxymethylene diphosphonate; D011433:Propranolol; D013015:Sotalol; D008790:Metoprolol; D004809:Ephedrine; D013726:Terbutaline; D013669:Technetium Tc 99m Medronate