AJP - Regulatory, Integrative and Comparative Physiology, Vol 254, Issue 4 567-R571, Copyright © 1988 by American Physiological Society
Immunoreactive atrial natriuretic factor is increased in ovine model of endotoxemia
H. J. Lubbesmeyer, L. Woodson, L. D. Traber, J. T. Flynn, D. N. Herndon and D. L. Traber
Department of Physiology, Anesthesiology, and Surgery, University of Texas Medical Branch, Galveston.
A bolus of Escherichia coli endotoxin (1.5 micrograms/kg) was administered
to chronically instrumented sheep. Immunoreactive atrial natriuretic factor
(IR-ANF) was measured in extracted plasma by radioimmunoassay. There was a
thirteenfold increase in IR-ANF 2 h after endotoxin administration, and
IR-ANF levels remained significantly elevated during the first 6 h. A
marked diuresis and natriuresis occurred between 4 and 6 h. ANF not only
affects renal function but is also associated with decreased cardiac
output, increased peripheral resistance (in sheep), and decreased capillary
absorption (in rats). These renal and hemodynamic changes are also
characteristic of the early (first 6 h) response to endotoxin. Therefore
ANF should be considered as a potential mediator of renal and hemodynamic
changes induced by sepsis. It is difficult to determine if ANF elevation is
an epiphenomenon or a causative factor, because no antagonist of ANF is
currently available.
