EFFECT OF VERAPAMIL ON MALIGNANT-TISSUE BLOOD-FLOW IN SMT-2A TUMOR-BEARING RATS

  • 1 January 1982
    • journal article
    • research article
    • Vol. 42  (10) , 3944-3949
Abstract
The influence of the Ca antagonist verapamil on malignant and normal tissue blood flow was investigated using 25-.mu.m 113Sn-labeled microspheres. Isogeneic Wistar-Furth rats were inoculated with a metastasizing mammary gland adenocarcinoma (SMT-2A) in the hindlimb musculature and mammary gland. Verapamil was administered as an i.v. bolus via an external jugular vein catheter followed by a supplemental constant infusion with a Harvard infusion pump. Plasma verapamil levels were determined by high performance liquid chromatography, and heart rate and systemic blood pressure were monitored. Verapamil in concentrations of 100-200 ng/ml resulted in an .apprx. 50% increase in tumor blood flow compared to controls levels (P < 0.001) regardless of the site of tumor implantation. These levels were not associated with a significant alteration in arterial blood pressure. Verapamil in concentrations currently used in humans may provide a means of improving the delivery of chemotherapeutic agents to solid neoplasms and may enhance the effectiveness of ionizing radiation treatment by increasing tumor oxygenation.