Role of Baroreceptor Resetting in the Tachycardia Observed During the Onset of One-Kidney, one Clip Hypertension

Abstract

A previous study from our laboratory demonstrated the occurrence of transient tachycardia during the onset of one-kidney, one clip (1K1C) hypertension in conscious rats. In the present study, using electroneurographic recordings in anesthetized rats, we investigated the time course of baroreceptor resetting at the onset (3, 7, 14 and 21 days) of 1K-1C hypertension. No significant difference between the diastolic pressure and the systolic threshold pressure for baroreceptor activation was detected in normotensive control rats and hypertensive rats 3, 7, 14 and 21 days after clipping. These data indicate that the baroreceptors were completely reset to the hypertensive levels during the periods studied. The data also suggest that baroreceptor resetting may play a facilitating role in the onset of tachycardia and the development of 1K1C hypertension in the conscious animal model.

Key Words:

• baroreceptor adaptation
• renal hypertension
• tachycardia
• baroreceptor reflex
• pressor receptors