Changes in regional hemodynamics after nitric oxide inhibition
during ovine bacteremia.
Lingnau, Werner, Roy McGuire, Deborah J. Dehring, Lillian D. Traber,
Hugo A. Linares, Sharon H. Nelson, Robert G. Kilbourn, Daniel L.
Traber.
Departments of Anesthesiology and Physiology and Biophysics, The
University of Texas Medical Branch and Shriners Burns Institute,
Galveston, TX 77555-0833
APStracts 2:0235R, 1995.
We studied the action of nitric oxide synthase (NOS) inhibition on
changes in regional blood flow during a continuous infusion of live
bacteria. Eighteen ewes were chronically instrumented. After a seven
-day recovery period, an infusion of 106 colony-forming units
(CFUs)/min Pseudomonas aeruginosa was begun. At 24 h, cardiac output
increased significantly above baseline in all groups (5.9+/-0.4 vs.
8.2+/-0.6 L/min/m2), systemic vascular resistance decreased (1362+/
-120 vs. 821+/-145 dyne x sec x cm-5 x m-2), and cerebral, cephalic
mesenteric, and hind limb blood flows increased. The animals were
then equally and randomly assigned to a bolus of a NOS inhibitor,
either 25 mg/kg Nw-nitro-l-arginine methyl ester (l-NAME) or 20 mg/kg
Nw-mono-methyl-l-arginine (l-NMMA), followed by a continuous infusion
of 7 mg/kg/min or saline. After NOS inhibition, cardiac output
decreased (5.6+/-0.4 [l-NAME] and 5.5+/-0.4 L/min/m2 [l-NMMA]) and
remained significantly decreased for 12 h. l-NAME decreased carotid
and mesenteric blood flows to 64% of the preseptic baseline and they
remained below baseline for 20 h. l-NMMA decreased blood flows only
to preseptic baseline values. NOS inhibitors may affect blood flows
independent of their hemodynamic effects.
Received 15 December 1994; accepted in final form 14 August 1995.
APS Manuscript Number R710-4.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 24 August 1995.