Short-period-induced hypertension could improve tumor-to-nontumor ratios of radiolabeled monoclonal antibody.

This study was undertaken to find optimum period of hypertensive treatment for the improvement of tumor targeting of 111In-labeled monoclonal antibody. Angiotensin II was infused into tumor-bearing mice at an infusion rate of 2.0 micrograms/kg/min determined by the dose-finding study. The infusion was continued for up to 72 h, and biodistribution of 111In-DTPA-A7, a murine IgG1, was observed 72 h postinjection. Tumor-to-nontumor ratios were best improved with the infusion for 0.5-3 h. However, with the longer infusion, the effect deteriorated by the increase of nontumor uptakes, and body-weight loss became remarkable. It could be concluded that hypertensive treatment for a short period could be safely performed to benefit targeting of radiolabeled monoclonal antibody.