Carotid artery injections in 40- to 99-g Fischer rats: technical note and evaluation of blood flow by various injection techniques.

Despite extensive clinical use of brain tumor chemotherapy via the internal carotid artery (ICA), demonstration of efficacy and toxicity screening of ICA chemotherapy in brain tumor models has been limited. A method for performing ICA injections in 40- to 99-g Fischer rats is described, with documentation of its effect upon cerebral blood flow. A 33 gauge cannula was secured into a PE-10 catheter and, after ligation of the external carotid (ECA) and the pterygopalatine arteries, injections were made into the common carotid artery (CCA). The reliability of this method compared to CCA injection with and without ligation of the ECA was evaluated utilizing 15-micrometers 103Ru microspheres. With this technique, 68.3 +/- 11.19% of the microspheres lodged in the brain, compared to 28.9 +/- 21.3% to 32.7 +/- 19.8% for the other techniques (P less than 0.01). With this technique, regional perfusion of brain tumors can be done in the avian sarcoma virus rat glioma model, the D-54 MG human glioma-immunosuppressed rat transplantation model, and any of the large rat brain tumor models. The relevance of this method of experimental regional perfusion for the preclinical assessment of the efficacy and of the toxicity of chemotherapy and immunotherapy via the ICA is discussed.