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SYMPATHETIC ACTIVATION IN SEPSIS INDUCED BY CECAL LIGATION AND PUNCTURE
Author(s) -
Barreto Carolina Ribeiro,
Aquino Freitas Raphael Ribeiro,
OliveiraSales Elizabeth Barbosa,
Campos Ruy Ribeiro,
Bergamaschi Cassia Toledo
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a591-a
Subject(s) - rostral ventrolateral medulla , kynurenic acid , medicine , microinjection , brainstem , sympathetic nervous system , sepsis , microinjections , heart rate , autonomic nervous system , splanchnic , anesthesia , blood pressure , ligation , hemodynamics , glutamate receptor , endocrinology , receptor
Experimental evidences show an important role of the autonomic nervous system (ANS) in the bidirectional communication between the brain and immune system. The major aim of the present study was to evaluate in an experimental model of sepsis induced by cecal ligation and puncture (CLP) the following: hemodynamic parameters, renal sympathetic activity and sympathetic activation mediated by the rostral ventrolateral medulla (RVLM). Experiments were performed in male Wistar rats (24 hours after CLP), which were divided in control (C, n=9) and sepsis (CLP, n=6). The CLP group showed a significant decrease in blood pressure (BP) (C: 109.1±1; CLP: 97.9±2mmHg) and an increase in cardiac output (C: 105.2±1; CLP: 180.5±3 ml/min P<0.05) and in heart rate (HR) (C: 376±12 S: 459.1±17bpm) compared to control group. The CLP group presented also an increase in renal sympathetic nerve activity (RSNA) (C: 116.2 ± 0.9; CLP: 205.1 ± 11 Hz, P<0.05). To evaluate the origin of this activation, glutamate and kynurenic acid were microinjected into the RVLM, a specific brainstem area involved in the control of sympathetic activity. The microinjection of glutamate into the RVLM increased BP in both groups (C: 109.1±1 to 163.7±8; CLP: 97.9±2 to 155.3±10mmHg) and HR (C: 376±12 to 397.6±13; CLP: 459.1±17 to 488.6±24bpm). Microinjections of kynurenic acid did not produce any changes in BP, HR or RSNA. These results suggest that the sympathetic activation found in CLP animals were not mediated by glutamatergic receptors in the RVLM. However, other neurotransmitters within the region may be involved in the sympathetic activation of this model. Supported by FAPESP.