Differences between the in vitro vasoconstrictor responses of the tail artery to potassium and norepinephrine between spontaneously hypertensive, renovascular hypertensive, and various strains of normotensive rats.

Isolated tail arteries removed from spontaneously hypertensive, renovascular hypertensive, or various strains of normotensive rats were perfused/superfused with norepinephrine or potassium, or subjected to electrical field stimulation. Responses in spontaneously hypertensive and outbred normotensive rat tail artery preparations were similar. Tail artery segments from renovascular hypertensive or normotensive rats of the inbred Wistar-Kyoto strain showed smaller responses to all three stimuli. Thus, in certain in vitro arterial preparations, the apparent increase in vascular reactivity observed when comparing spontaneously hypertensive rats with inbred Wistar-Kyoto rats may be due to a decrease in vascular reactivity in the Wistar-Kyoto rat strain.