Abstract
Adrenocorticotropic hormone (ACTH) release from anterior pituitary corticotropes is greatly increased during peripheral inflammation induced by lipopolysaccharide (LPS) administration. Interleukin-6 (IL-6) is thought to participate in LPS-induced ACTH release, but whether or not corticotropes are directly targeted by this cytokine is unclear. Therefore, we investigated the expression and activation of IL-6 signaling components in the pituitary of rats 2 and 4 h after administration of LPS (250 μg/kg). Intraperitoneal LPS treatment provoked the nuclear translocation of signal transducer and activator of transcription 3 (STAT-3) and Fos expression in the anterior pituitary lobe, as demonstrated by immunohistochemistry. By using in situ hybridization, we demonstrated that suppressor of cytokine signaling 3 (SOCS-3) and c-fos mRNAs were significantly induced by the LPS treatment in the anterior lobe of the pituitary. Dual in situ hybridization revealed that most corticotropes expressed IL-6 receptor and gp130 mRNAs, and that 2 h after LPS treatment, SOCS-3 and c-fos mRNAs were induced in corticotropes. Our results suggest that LPS-induced IL-6 could regulate the hypothalamo-pituitary-adrenal axis by directly targeting corticotropes during peripheral inflammation.
Original language | English (US) |
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Pages (from-to) | 32-43 |
Number of pages | 12 |
Journal | Neuroendocrinology |
Volume | 77 |
Issue number | 1 |
DOIs | |
State | Published - Mar 20 2003 |
Keywords
- Corticotropes
- Fos
- Immunocytochemistry
- In situ hybridization
- Inflammation
- Interleukins
- Lipopolysaccharide
- Neuroimmune interactions
- Proopiomelanocortin
- STAT-3
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Endocrinology
- Endocrine and Autonomic Systems
- Cellular and Molecular Neuroscience