Sympathetic nerve activities in pulsatile and nonpulsatile systemic
circulation in anesthetized goats.
Toda, Koichi, Eisuke Tatsumi, Yoshiyuki Taenaka, Toru Masuzawa,
Hisateru Takano.
Department of Artificial Organs, National Cardiovascular Center
Research Institute, Suita, Osaka 565, Japan
APStracts 2:0549H, 1995.
To investigate the effects of pulsatile and nonpulsatile systemic
circulation on the sympathetic nerve activity, we converted systemic
circulation between pulsatile and nonpulsatile modes in anesthetized
goats using a left heart bypass technique and analyzed differences in
periodicity and quantity of renal nerve activity (RNA). After
pulsatile systemic circulation was converted to nonpulsatile mode,
the mean RNA was significantly increased from 10.7 +/- 3.6 [mu]V to
13.1 +/- 3.4 [mu]V and periodic discharges of RNA which corresponded
to pulse-related rhythm during pulsatile circulation became obscure,
while an 8-12 cycles/s rhythm which was distinguished and accounted
for 30 +/- 9% of total intervals during pulsatile circulation became
dominant (48 +/- 11%). These results clarified a significant increase
of mean RNA after depulsation of the systemic circulation and
indicated that the cardiac-related rhythm in RNA could be produced by
periodic inputs from arterial baroceptors alone whereas the 8-12
cycles/s rhythm that was present regardless of the types of
circulation was the fundamental rhythm originating from the vasomotor
center.
Received 21 February 1995; accepted in final form 1 December
1995.
APS Manuscript Number H162-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 8 December 95