Cardiovascular adjustments induced by hypertonic saline in hemorrhagic rats: involvement of carotid body chemoreceptors
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Data
2011
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Resumo
The peripheral hyperosmolarity elicited by intravenous infusion of hypertonic saline brings potential benefits
to the treatment of hemorrhage. The neural mechanisms involved in these beneficial effects remain unknown.
The present study examines the role of carotid chemoreceptors in cardiovascular responses induced by
hypertonic saline after hypovolemic hemorrhage in rats. Male Wistar rats (300–400 g) were anesthetized
with thiopental, and instrumented for recording of mean arterial pressure. Arterial pressure was reduced to
60 mmHg by withdrawal of arterial blood over 10 min, and maintained at this level for 60 min by withdrawal
or infusion of blood. In control rats (n=8) with intact chemoreceptors, the subsequent intravenous infusion
of hypertonic saline (3 M NaCl, 1.8 ml kg−1 body weight, in 2 min) restored blood pressure (pressure
increased from 61±4 to 118±5 mm Hg). In experimental rats (n=8), the carotid body arteries were tied,
30 min after the beginning of the hypotensive phase, leaving the carotid chemoreceptors ischemic. In these
rats, hypertonic saline failed to restore blood pressure (pressure increased from 55±1 to 70±6 mm Hg).
These findings suggest that the restoration of blood pressure after hypovolemic hemorrhage induced by
hypertonic saline depends on intact carotid chemoreceptors.
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Hypovolemic hemorrhage, Arterial blood pressure and heart rate, Hypertonic saline
Citação
PEDRINO, Gustavo R. et al. Cardiovascular adjustments induced by hypertonic saline in hemorrhagic rats: involvement of carotid body chemoreceptors. Autonomic Neuroscience: basic & clinical, Amsterdam, v. 160, p. 37-41, 2011.