Arterial pulse pressure and vasopressin release in humans during lower body negative pressure.
The hypothesis was tested that narrowing of arterial pulse pressure (PP) is a determinant of arginine vasopressin (AVP) release in humans. Six normal males completed a two-step lower body negative pressure (LBNP) protocol of -20 and -50 mmHg, respectively, for 10 min each. None of these subjects experienced presyncopal symptoms. Arterial plasma AVP and plasma renin activity (PRA) (at 2-min intervals) only increased subsequent to a decrease in PP (invasive brachial arterial measurements) and stroke volume (ultrasound Doppler technique, n = 4). Simultaneously, mean arterial pressure did not change. A selective decrease in central venous pressure and left atrial diameter (echocardiography, n = 4) at LBNP of -20 mmHg did not affect AVP or PRA, whereas arterial plasma norepinephrine increased (n = 4). During LBNP, significant (P < 0.05) intraindividual linear correlations were observed between log(AVP) and PP in four of the subjects with r values from -0.75 to -0.99 and between log(PRA) and PP in all six subjects with r values from -0.89 to -0.98. In conclusion, these results are in compliance with the hypothesis that narrowing of PP in humans during central hypovolemia is a determinant of AVP and renin release.
Norsk
P
P
Danish Aerospace Medical Centre of Research, Rigshospitalet, Copenhagen.
Ellegaard
P
P
Videbaek
R
R
Stadeager
C
C
Jessen
F
F
Johansen
L B
LB
Kristensen
M S
MS
Kamegai
M
M
Warberg
J
J
Christensen
N J
NJ
D000328:Adult; D001127:Arginine Vasopressin / Q000097:blood*; D001158:Arteries / Q000502:physiology*; D001794:Blood Pressure; D002320:Cardiovascular Physiological Phenomena; D004702:Endocrine Glands / Q000502:physiology; D006801:Humans; D008150:Lower Body Negative Pressure; D008297:Male; D009994:Osmolar Concentration; D011674:Pulse
D001127:Arginine Vasopressin