AIM: These studies were undertaken in intact spontaneously hypertensive rats (SHR) to assess whether the elastic behavior of conduit arteries changes as a function of age. METHODS: We studied 16-week-old (n = 10) and 36-week-old (n = 10) SHR under fluothane anesthesia. Diameter-, compliance-, and distensibility-pressure curves were established non-invasively for the carotid artery by means of a high-precision ultrasonic echo-tracking device. Intra-arterial pressure was monitored simultaneously in the contralateral carotid artery. RESULTS: Mean blood pressure was 197 +/- 6 and 185 +/- 3 mmHg (mean +/- SEM) in the younger and older SHR, respectively. No significant difference was observed between the two groups of rats in the diameter-, compliance- and distensibility-pressure curves. CONCLUSIONS: These results suggest that the elastic behavior of elastic arteries is not necessarily altered with aging in rats with genetic hypertension.