The synthesis, radioiodination and preliminary biological study of the new carboxylic derivatives of dithizone.

Synthesis, characteristics and radioiodination of the new carboxylic derivatives of dithizone are described in this paper. We have applied the carboxy dithizones for preparation of radioactive compounds by coupling with [131I]-histamine. Preliminary biological studies of the new radiodithizone were done in rats after two different application routs: peripheral i.v. injection and direct injection to splenic artery. Biodistribution of the carboxy dithizone-[131I]-histamine conjugate (i.v. injection) was quite different than that for free [131I]-histamine. However, uptake of activity in pancreas was low (0.81% g-1 of tissue). Direct application of the conjugate to splenic artery resulted in high activity retention in pancreas after 30 and 45 min post injection (respectively 8.8 and 12.4% g-1 of tissue) indicating potential usefulness of the new radiodithizone for in vivo monitoring of pancreas.