Lanreotide, a somatostatin analogue, reduces insulin-like growth factor I accumulation in proliferating aortic tissue in rabbits in vivo. A preliminary study.

Coronary artery restenosis following percutaneous transluminal angioplasty occurs with a very high incidence. Major efforts have been aimed at revealing the mechanisms and at developing therapies that might prevent or delay the myointimal proliferation. Most clinical trials have been unsuccessful. Endothelial denudation was induced in 30 rabbits using balloon catheterization of iliac arteries and aorta. Immunoreactive insulin-like growth factor I (IGF-I) was measured in arterial tissue samples obtained 1, 2 and 4 days postoperatively using a double extraction procedure to remove IGF-I binding proteins. Half of the animals were treated with subcutaneous injections of lanreotide, 10 micrograms/kg twice daily, and the other half served as controls. In the latter group, arterial IGF-I was unaltered from baseline at day 1 and increased by 300 and 400% at days 2 and 4. No increase was observed in the rabbits treated with lanreotide. The results indicate that initial local accumulation of IGF-I may be one of the mechanisms involved in myointimal proliferation after experimental arterial injury. The reduction of local IGF-I accumulation by lanreotide may be involved in the previously observed reduction in myointimal proliferation.