Whalen, EJ, Johnson, AK and Lewis, SJ (2014) Hemodynamic responses elicited by systemic injections of isotonic and hypertonic saline in hemorrhaged rats. Microvascular Research. pp. 22-29.

Abstract

Purpose: The objectives of this study were (i) to characterize the hemodynamic responses caused by controlled hemorrhage (HEM) in pentobarbital-anesthetized rats, and (ii) to determine the responses elicited by systemic bolus injections of isotonic saline (0.15. M) or hypertonic saline (3. M) given 5. min after completion of HEM. Results: Controlled HEM (4.3. +. 0.2. ml/rat at 1.5. ml/min) resulted in a pronounced and sustained fall in mean arterial blood pressure (MAP) to about 40. mm. Hg. The fall in MAP was associated with a reduction in hindquarter vascular resistance (HQR) but no changes in renal (RR) or mesenteric (MR) vascular resistances. Systemic injections of isotonic saline (96-212. mumol/kg i.v., in 250-550. mul) did not produce immediate responses but promoted the recovery of MAP to levels below pre-HEM values. Systemic injections of hypertonic saline (750-3000. mumol/kg, i.v., in 250-550. mul) produced immediate and pronounced falls in MAP, RR, MR and especially HQR of 30-120. s in duration. However, hypertonic saline prompted a full recovery of MAP, HQR and RR to pre-HEM levels and an increase in MR to levels above pre-HEM values. Conclusions: This study demonstrates that (i) HEM induced a pronounced fall in MAP which likely involved a fall in cardiac output and HQR, (ii) isotonic saline did not fully normalize MAP, and (iii) hypertonic saline produced dramatic initial responses, and promoted normalization of MAP probably by restoring blood volume and cardiac output through sequestration of fluid from intracellular compartments. 2013 Elsevier Inc

Item Type:	Article
Additional Information:	NIBR author: Whalen, EJ institute: NIBR- address only contributor address: (Whalen, Johnson) Department of Psychology, University of Iowa, Iowa City, IA, United States (Whalen, Johnson) Department of Pharmacology, University of Iowa, Iowa City, IA, United States (Whalen, Johnson) The Cardiovascular Center, University of Iowa, Iowa City, IA, United States (Lewis) Department of Pediatrics, Case Western Reserve University, Cleveland, OH, United States (Whalen) Novartis Institutes for Biomedical Research, 100 Technology Square, Cambridge, MA 02139, United States
Date Deposited:	13 Oct 2015 13:12
Last Modified:	13 Oct 2015 13:12
URI:	https://oak.novartis.com/id/eprint/22662