Biodistribution of two 99mTc-cardiac glycosides with end glucose unit: effect of lipophilicity on their relative myocardial accumulation.
In biodistribution experiments with tritium labelled cardiac glycoside it was observed that compounds of low lipophilicity showed a considerably higher affinity towards myocardium with respect to other tissues and organs. A similar trend was also observed with 99mTc-cardiac glycosides except for one compound with glucose residue, which in spite of its lower lipophilicity exhibited an unexpectedly low heart to non-target concentration ratio, thereby indicating a possible influence of carbohydrate residue on biodistribution. To confirm this, in this article we radiolabelled two glucose containing cardiac glycosides (K-strophanthin-beta and K-strophanthoside) with 99mTc and, in biodistribution experiments, less lipophilic 99mTc-K-strophanthoside showed a much better heart to non-target ratio over 99mTc-K-strophanthin-beta. It is thus concluded that, in addition to lipophilicity, the affinity of the carbohydrate residue for non-target organs is also an important consideration in determining the structure-distribution relationship of 99mTc-cardiac glycosides.
Sarkar
H S
HS
Indian Institute of Chemical Biology, Calcutta.
Misra
M
M
Banerjee
S
S
D000818:Animals; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D006027:Glycosides / Q000493:pharmacokinetics*; D006168:Guinea Pigs; D050356:Lipid Metabolism; D015394:Molecular Structure; D009206:Myocardium / Q000378:metabolism*; D009942:Organometallic Compounds / Q000493:pharmacokinetics*; D015609:Organotechnetium Compounds; D013328:Strophanthins / Q000493:pharmacokinetics*; D014018:Tissue Distribution
D006027:Glycosides; D009942:Organometallic Compounds; D015609:Organotechnetium Compounds; D013328:Strophanthins; C059577:technetium Tc 99m K-strophanthin-beta