Regional vascular responses to an acute stressor in spontaneously hypertensive and Wistar-Kyoto rats.

The regional vascular responses to an acute intermittent footshock stressor were examined in Wistar-Kyoto and spontaneously hypertensive rats using the pulsed Doppler flow probe method. While both strains exhibited vascular resistance changes, which were typical of the 'defense response', the changes in regional vascular resistance were exaggerated in the spontaneously hypertensive rats compared to the Wistar-Kyoto. Despite these alterations in vascular resistance, and greater increases in heart rate in the spontaneously hypertensive rats, there were no differences in the pressor responses footshock between the Wistar-Kyoto and spontaneously hypertensive rats. These findings indicate that very specific regional hemodynamic changes accompany the characteristic sympathetic nervous system hyperresponsiveness of spontaneously hypertensive rats to environmental stress.