J Korean Pediatr Soc.  1995 Jan;38(1):61-65.

Comparison of Graded and Bolus Infusion Methods in Baroreflex Measurements in Rabbits

• Joo CU

Abstract

Graded infusion and bolus injection methods of vasoactive drugs have both been used to measure baroreflex sensitivity. To determine whether the two methods produce the same values of baroreceptor sensitivity, phenylephrine and nitroglycerin was administered intravenously by both graded infusion and bolus injection methods to 11 rabbits. To evaluate the baroreflex control of heart rate(HR), a logistic sigmoid function model was used. The range of HR and baroreflex gain by the bolus method(100.53+/-0.62, 0.113+/-0.011) were significantly(p<0.05) larger than those measured by the graded infusion method(108.49+/-1.66, 0.126+/-0.013). However, there were no significant changes in the pressure at the midrange of the baroreflex curve. Thus my results indicate that baroreflex control of HR by the graded infusion and bolus injection methods is not equivalent and that baroreflex-induced HR response to a gradual change in pressure is less than that seen with a repid change.

Keyword

Baroreflex sensitivity; Heart rate; Bolus and infusion method

MeSH Terms

Baroreflex*
Colon, Sigmoid
Heart
Heart Rate
Nitroglycerin
Phenylephrine
Pressoreceptors
Rabbits*
Nitroglycerin
Phenylephrine