Biodistribution of [111In-DTPA-D-Phe1]-octreotide in dogs: uptake in the stomach and intestines but not in the spleen points towards interspecies differences.

The purpose of the present study was to establish the tissue distribution in abdominal organs and the excretion of radioactivity after intravenous administration of [(111)In-DTPA-D-Phe(1)]-octreotide in healthy dogs. In five Beagle dogs computed tomography and single photon emission computed tomography (SPECT) at 24 h after injection of [(111)In-DTPA-D-Phe(1)]-octreotide revealed accumulation of radioactivity in the kidneys, gall bladder, gastric fundus and cardia, intestinal tract, but not in the spleen. These findings were confirmed by in vitro scintigraphy of single abdominal organs.

Co-expressed peptide receptors in breast cancer as a molecular basis for in vivo multireceptor tumour targeting.

Breast cancers can express different types of peptide receptors such as somatostatin, vasoactive intestinal peptide (VIP), gastrin-releasing peptide (GRP) and NPY(Y(1)) receptors. The aim of this in vitro study was to evaluate which is the most appropriate peptide receptor or peptide receptor combination for in vivo diagnostic and therapeutic targeting of breast cancers. Seventy-seven primary breast cancers and 15 breast cancer lymph node metastases were investigated in vitro for their expression of somatostatin, VPAC(1), GRP and NPY(Y(1)) receptors using in vitro receptor autoradiography on successive tissue sections with (125)I-[Tyr(3)]-octreotide, (125)I-VIP, (125)I-[Tyr(4)]-bombesin and (125)I-[Leu(31),Pro(34)]-PYY respectively.