Preparation and bioevaluation of 99mTc-carbonyl complex of 5-hydroxy tryptamine derivative

Studies on the development of imaging agents for targeting neuroreceptors is an area of considerable interest owing to the limited availability of specific as well as selective radiolabeled agents. Therefore, with an aim of developing a receptor-specific agent, iminodiacetic acid (IDA) derivative of 5-hydroxy tryptamine viz., HTIDA has been synthesized. HTIDA could be radiolabeled with the synthon [99mTc(CO)3(H2O)3]+ in >98% yield. The biodistribution studies in normal Swiss mice showed that the 99mTc(CO)3-HTIDA crosses the blood-brain barrier successfully with a brain uptake of 0.5%ID/g at 5 min post injection. The other relevant observations from biodistribution studies included no significant uptake in any other organ and fast clearance from blood, lungs and liver.