AJP - Regulatory, Integrative and Comparative Physiology, Vol 242, Issue 3 244-R246, Copyright © 1982 by American Physiological Society
Phylogenesis of the Bainbridge reflex
D. H. Boettcher, M. Zimpfer and S. F. Vatner
The effects of volume loading were examined on measurements of left
ventricular (LV) pressure and heart rate in patients undergoing cardiac
catheterization. These data were compared to those collected in conscious
dogs and subhuman primates (baboons). In man acute volume loading increased
LV end-diastolic pressure by 14 mmHg, but did not increase LV systolic
pressure significantly. Similar increases in LV end-diastolic pressure were
observed in conscious dogs and baboons. LV systolic pressure also did not
rise in baboons, but did increase (+32 mmHg) with volume loading in dogs.
In man volume loading increased heart rate by 15 beats/min, significantly
less (P less than 0.01) than observed in baboons (+37 beats/min), and which
in turn was significantly less than that observed in dogs (+88 beats/min).
Thus, the Bainbridge reflex, i.e., the tachycardia that occurs with volume
loading, appears to exist in primates including man. However, the extent of
utilization of this reflex decreases significantly from nonprimate mammals
(dogs) to subhuman primates (baboons) to man.
