Effect of verapamil on malignant tissue blood flow in SMT-2A tumor-bearing rats

Cancer Res. 1982 Oct;42(10):3944-9.


We investigated the influence of the calcium antagonist verapamil on malignant and normal tissue blood flow using 25-micrometer 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 to 200 ng/ml resulted in an approximate 50% increase in tumor blood flow compared to control levels (p less than 0.001) regardless of the site of tumor implantation. These levels were not associated with a significant alteration in arterial blood pressure. These data suggest that verapamil in concentrations currently used in humans may provide a means of improving the delivery of chemotherapeutic agents to solid neoplasms and may also enhance the effectiveness of ionizing radiation treatment by increasing tumor oxygenation.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenocarcinoma / blood supply*
  • Animals
  • Blood Pressure / drug effects
  • Cardiac Output / drug effects
  • Female
  • Heart Rate / drug effects
  • Mammary Neoplasms, Experimental / blood supply*
  • Mammary Neoplasms, Experimental / physiopathology
  • Rats
  • Rats, Inbred Strains
  • Regional Blood Flow / drug effects*
  • Vascular Resistance / drug effects
  • Verapamil / blood
  • Verapamil / pharmacology*


  • Verapamil