Evaluation of blood pressure measured by tail-cuff methods (without heating) in spontaneously hypertensive rats

Conventional noninvasive blood pressure in conscious rats or mice are typically measured using the tail-cuff method after heating the animal. The goal of this study was to assess the validity of a novel tail-cuff method without animal heating when compared with the conventional heating tail-cuff method (unanesthetized rats with heating), telemetry method (unanesthetized restrained rats without heating), or carotid arterial catheter method (anesthetized rats, carotid arterial cannulation). The blood pressure and heart rate of spontaneously hypertensive rats were measured at 13:00-17:00 h for all experiments. Experiments demonstrated similar systolic blood pressure measurements when comparing the unheated-animal tail-cuff method and the telemetry method. Further, values obtained by both methods were lower than those obtained by the heated-animal tail-cuff method. Systolic blood pressure measurements obtained through carotid arterial cannulation were lower than those obtained by any other method. The heart rate was highest using the unheated-animal tail-cuff method when compared with the other methods. These data suggest that the novel unheated-animal tail-cuff method is a sensitive and accurate approach for the noninvasive measurement of blood pressure in conscious rats.