Tachycardia during reversal of one-kidney, one-clip hypertension in conscious rats.
The efferent sympathetic activity of the heart was investigated during reversal of one-kidney, one-clip (1K,1C) hypertension in conscious, freely moving rats using changes in heart rate as an index. One-kidney, one-clip hypertensive rats presented marked tachycardia during the first 8 h after unclipping. Mean arterial pressure fell 28% 3 h after unclipping and 37% 8 h after unclipping. In a separate experiment, short term infusion (15 min) of sodium nitroprusside in conscious freely moving rats produced similar tachycardia in hypertensive and sham-operated rats. The present results indicate that the baroreceptor reflex of the heart was operating normally during the prompt reversal of hypertension after unclipping.
Machado
B H
BH
Department of Physiology, School of Medicine of Ribeirão Preto, USP, São Paulo, Brazil.
Salgado
H C
HC
D000818:Animals; D001794:Blood Pressure; D006339:Heart Rate; D006977:Hypertension, Renal / Q000503:physiopathology*; D008297:Male; D009392:Nephrectomy; D011311:Pressoreceptors / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D012018:Reflex / Q000502:physiology; D013610:Tachycardia / Q000503:physiopathology*