TY - JOUR A1 - Soto, Luis J. AU - Martín Velasco, Ana Isabel AU - Millán, Salvador AU - Vara, Elena AU - López-Calderón, Asunción T1 - Effects of endotoxin lipopolysaccharide administration on the somatotropic axis  Y1 - 1998 SN - 00220795 UR - http://hdl.handle.net/11268/6231 AB - The aim of this work was to study the effect of chronic activation of the immune system on the somatotropic axis. Accordingly, the changes in growth hormone (GH) secretion, circulating insulin-like growth factor-I (IGF- I) and IGF binding proteins (IGFBPs) in response to endotoxin lipopolysaccharide (LPS) administration were examined in adult male Wistar rats. Acute LPS injection (2.5, 25 or 250 μg/kg) increased serum corticosterone in a dose-dependent manner and decreased serum levels of insulin and IGF-I, serum GH concentration declined linearly as the LPS dose increased. Western ligand blot showed an increase in the 33 kDa band (corresponding to IGFBP-1 and IGFBP-2) in the rats that received the highest dose of LPS (250 μg/kg). Chronic LPS administration (250 μg/kg daily for 8 days) significantly decreased body weight, serum levels of IGF-I and pituitary GH content, whereas it increased circulating IGFBP-3 (47 kDa band), IGFBP-1 and IGFBP-2 (33 kDa band) and the 24 kDa band (which possibly corresponds to IGFBP-4). Serum concentration of corticosterone and hypothalamic somatostatin content were also increased by chronic LPS treatment. These data suggest that the decrease in GH and IGF-I secretion and the increase in circulating IGFBPs are important mechanisms in body weight loss during chronic inflammation. KW - Endocrinología KW - Somatotropina KW - Corticosteroides KW - Endocrinología KW - Hormona LA - eng ER -