The efficacy of using
colloids and crystalloids in the treatment of
hypovolemia still remains controversial. An important aspect in treating
hypovolemia is to re-establish normal tissue hemodynamics after fluid
resuscitation. Production of
nitric oxide (NO) or
growth factors such as
transforming growth factor beta (
TGF-beta) has been identified as a key mechanism in physiological and
pathological processes in the different systems. This study was designed to investigate the histophysiological effects of
resuscitation with different
plasma substitutes on the heart, lung and brain tissues following acute blood loss in male Sprague-Dawley rats weighing 250-280g (
n=30). After
anesthesia with
sodium pentobarbital, the left femoral vein and artery were cannulated for the administration of volume expanders and for direct measurement of arterial pressure and heart rate. Twenty rats were bled (5ml/10min) and infused (5ml/10min) with one of four randomly selected solutions, (a)
human albumin, (b)
gelatin (
Gelofusine), (c) dextran-70 (
Macrodex); or (d) physiological
saline (0.9% isotonic saline). Five control rats were bled without infusion. Tissue samples were taken and fixed in 10%
formalin solution, then processed for embedding in
paraffin wax. Sections were cut and stained with
hematoxylin and
eosin. Indirect immunohistochemical labelling was performed to reveal binding of primary
antibodies against
endothelial nitric oxide synthase (eNOS),
inducible nitric oxide synthase (iNOS) and
TGF-beta. Mild immunoreactivity of eNOS was observed in endothelial cells of vessels in brain, heart and lung tissues. Increased immunoreactivities of eNOS, iNOS and
TGF-beta were observed in the non-fluid resuscitated group in these organs; mild, moderate, moderate and strong immunoreactivities were seen in the
albumin,
gelatin, physiological saline and dextran-70 treated groups, respectively. Immunoreactivities of iNOS and
TGF-beta in the non-fluid resuscitated group were increased significantly, in comparison to the other groups, apart from the dextran-70 treated group. The results of this study show that
gelatin solution and physiological saline may be of use after acute blood loss, and dextran-70 is not the preferred
resuscitation fluid in the early stages of acute blood loss. It was concluded that
albumin solution is the preferred fluid for
resuscitation.