Disturbances of the hypothalamic-pituitary-adrenal axis and plasma electrolytes during experimental sepsis

Sepsis was induced in adult male Sprague-Dawley rats by cecal ligation and puncture (CLP). Plasma samples were obtained as a function of time (6-48 hrs) after CLP and compared with healthy animals (neg ctrl). Samples were analyzed for adrenocorticotropin (ACTH), corticosterone, and aldosterone levels, as well as concentrations of sodium (Na+), potassium (K+), chloride (Cl-), and magnesium (Mg2+).ACTH levels were found to be significantly reduced 6-24 hrs after CLP in comparison to baseline levels and displayed gradual recovery during the later course (24-48 hrs) of sepsis. Plasma corticosterone concentrations exhibited a bell-shaped response, peaking between 6 and 12 hrs followed by rapid decline and concentrations below negative control levels 48 hrs after injury. Aldosterone levels in septic animals were continuously elevated between 6 and 48 hrs. Whereas plasma Na+ levels were found to be persistently elevated following CLP, levels of K+, Cl- and Mg2+ were significantly reduced as a function of time and gradually recovered during the later course of sepsis.CLP-induced sepsis resulted in dynamic changes of ACTH, corticosterone, and aldosterone levels. In addition, electrolyte levels showed significant disturbances after CLP. These electrolyte perturbations might be evoked by a downstream effect or a dysfunctional HPA-axis response during sepsis and contribute to severe complications during sepsis.Sepsis remains an enigmatic, poorly understood disease [1]. Disturbingly, there has been a rapid increase of hospitalization and mortality rates between 1993 and 2003 [2], making sepsis the tenth leading cause of death in the United States [3]. Despite numerous encouraging preclinical results for new therapeutic approaches to sepsis, a successful transfer from "bench to bedside" has yet to be achieved [4-10]. Various randomized clinical trials investigating anti-inflammatory strategies have failed to show any survival improvement [11]. To date, the only clearly beneficial