Skip to main content

Volume 14 Supplement 2

Sepsis 2010

Neonatal immune challenge impairs endotoxemic shock-induced hypotension: potential role for vasopressin

Administration of bacterial cell wall component lipopolysaccharide (LPS) stimulates the immune and endocrine systems, inducing acute phase of sickness and stress responses. Neonatal LPS exposure has been shown to alter many aspects of adult physiology, including neuroendocrine, neurochemical, and febrile responses. The aim of this study was to evaluate the effects of neonatal immune challenge on adults during septic shock-like condition assessing mean arterial pressure and heart rate, plasma vasopressin (AVP) concentration, body temperature (Tb), and macrophage nitric oxide (NO) synthesis. Male Wistar rats were exposed to LPS (100 μg/kg i.p.; nLPS) or saline administration (nSal) 14 days after birth (P14). On day 50 after birth, endotoxemic shock was induced by intraperitoneal injection of 10 mg/kg LPS, on rats previously implanted with polyethylene catheters in the femoral artery and loggers for Tb measurements. A different set of animals was used to assess the effect of neonatal LPS exposure on NO synthesis by peritoneal macrophage in vitro, with (1 μg/ml) or without LPS, added to the culture. In nSal rats, LPS injection induced a transitory increase in AVP plasma concentration, a decrease in mean arterial pressure with a concomitant increase in heart rate, which were statistically significant from 1 hour (P < 0.01) up to 6 hours (P < 0.001) after treatment. LPS-induced hypothermia (P < 0.05) was observed for 2 hours after LPS administration, and was followed by an increased Tb (P < 0.01). We also observed a significant increase in nitrate plasma concentration as well as in macrophage culture medium after LPS stimulation. In nLPS rats we observed an attenuation to the development of hypotension, no significant change in heart rate (P < 0.05), an increased hypothermia, and a decreased febrile response, and further increased (P < 0.01) AVP plasma levels were observed, in response to LPS administration. Interestingly, nitrite released in the culture medium was attenuated in nLPS animals. Neonatal exposure to LPS induces attenuation in hypotension during septic shock-like conditions and this response may involve an increased AVP release.

Author information



Corresponding author

Correspondence to EC Carnio.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Carnio, E., Cola, D. & Branco, L. Neonatal immune challenge impairs endotoxemic shock-induced hypotension: potential role for vasopressin. Crit Care 14, P15 (2010).

Download citation


  • Nitric Oxide
  • Vasopressin
  • Neonatal Exposure
  • Febrile Response
  • Plasma Vasopressin