Influence of oxygen deprivation, reduced flow, and temperature on
the release of atrial natriuretic peptide from rabbit hearts.
Focaccio, Amelia, Giuseppe Ambrosio, Iolanda Enea, Rosaria Russo,
Pasquale Balestrieri, Massimo Chiariello, Massimo Volpe.
Department of Medicine, Federico II School of Medicine, Naples, and
the Division of Cardiology, University of Perugia School of Medicine,
Perugia, Italy., Present address of Dr. Ambrosio: Division of
Cardiology $QUOTR$QUOT, University of Perugia School of Medicine, Via
Eugubina, Perugia, Italy.
APStracts 2:0097H, 1995.
The separate effects of hypoxia and ischemia on atrial natriuretic
peptide (ANP) release were evaluated in Langendorff-perfused rabbit
hearts. Heart rate, coronary flow, and atrial and ventricular volumes
were kept constant. Hypoxia was induced for 20 min at room
temperature in 7 hearts and at 37 degrees C in a second group of 7
hearts. A third group of 8 hearts was subjected to global ischemia
for 20 min by reducing coronary flow to 1 ml/min at room temperature.
All hearts were reoxygenated/reperfused at 37 degrees C for 30 min.
Hypoxia at 37 degrees C induced a significant increase in ANP
release. In contrast, both RT-hypoxia and ischemia were characterized
by a significant decrease in ANP release, in spite of hemodynamic
alterations similar to those recorded during hypoxia at 37 degrees C.
Both reoxygenation and reperfusion induced a prompt reversal of the
changes of ANP release observed during the period of oxygen
deprivation. These data demonstrate that decreased oxygen
availability and reduced coronary flow are not the primary factors
affecting release of ANP during ischemia, and that alterations of
myocardial temperature may play a major role in this phenomenon.
Received 1 August 1994; accepted in final form 18 January 1995.
APS Manuscript Number H667-4.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 21 March 1995.