Rat model for evaluation of therapeutics on peripheral vascular resistance

Described in this protocol is a rat preparation that serves as a sensitive, reliable in vivo assay of peripheral vascular resistance. Experiments are conducted on conscious animals 5 days following the surgical implantation of an arterial pressure catheter in the carotid artery and a transit time flow probe on the abdominal aorta. The transit time flow probe measures volume blood flow per unit time, making it possible to calculate a true vascular resistance, a reliable indicator of microvascular tone. After allowing appropriate recovery time between experiments, it is possible to use the animal preparation multiple times. This increases study efficiency by reducing the number of animals required and makes it possible to use paired statistical analysis since multiple treatment interventions, including control conditions, can be evaluated in each animal.