Relationship of chemical structure to in vivo scintigraphic distribution patterns of 11C compounds. I. 11C-carboxylates.

Abstract

Presently available data from experiments using 14C labeled compounds are insufficient to adequately predict the relationship between structure of an organic compound and its in vivo distribution pattern as studied by scintigraphic techniques.This is so for several reasons.The inherent low specific activity of ' 4C labeled.compounds makes 14C an unsuitable label for evaluation of in vivo distribution patterns of molecules whose in vivo distribution demonstrates a strong "carrier" effect in the range of the quantity of.14C labeled material required for the experiment.Studies of in vivo distribution patterns of 14C compounds requires serial sacrifice of essentially identical isogenic animals and assessment of changes in, 14C activity in organs in vitro as a function of time after administration.This demands a priori insight in choosing the proper time intervals for such sacrifice and selection of samples of the proper tissues for in vitro assay to detect in vivo distribution behavior of interest occurring at a given time in a given tissue.