Modulation of type I interleukin-1 receptor messenger RNA followed by one and repeated endotoxin treatment in the mouse.
The expression of transcripts for type 1 interleukin-1 receptors (IL-1R1) were investigated utilizing reverse transcription-polymerase chain reaction (RT-PCR) techniques in male C57BL/6 mice. First, we measured IL-1R1 mRNA 1, 2, 6, and 12 h after a single injection of endotoxin lipopolysaccharide (LPS; 30 microg/mouse). IL-1R1 mRNA was measured in relevant tissues utilizing semiquantitative RT-PCR. IL-1R1 mRNA levels were significantly increased 2 and 6 h after one LPS injection group in comparison with the saline injection group in the hippocampus and testis. Next, we investigated the effect of repeated injections of LPS on IL-1R1 expression. LPS or saline were injected at 24-h intervals for 4 consecutive days. The mice were divided into four groups: (1) LPS injections for 4 days and LPS injection on day 5 (LPS-LPS); (2) LPS injections for 4 days and saline injection on day 5 (LPS-saline); (3) saline injections for 4 days and LPS injection on day 5 (saline-LPS); (4) saline injections for 4 days and saline injection on day 5 (saline-saline). The mice were sacrificed by decapitation 2 h after the last injection. In the hippocampus and pituitary gland, significant increases of IL-1R1 mRNA levels were observed in the saline-LPS group, however, the increases were attenuated in LPS-LPS group. IL-1R1 mRNA levels in the hypothalamus were unchanged in all four groups. In the adrenal gland and testis, IL-1R1 mRNA levels were significantly increased in the LPS-LPS group as well as saline-LPS group. These data demonstrate differential regulation of IL-1R1 mRNA by one and repeated endotoxin treatment and suggest the importance of the cytokines in mediating the effects of infectious challenge on brain, endocrine and immune function during endotoxemia.
Nagano
I
I
Second Department of Internal Medicine, Kochi Medical School, Kohasu, Okoh-cho, Nankoku, Kochi, Japan. naganoi@kochi-ms.ac.jp
Takao
T
T
Nanamiya
W
W
Hashimoto
K
K
D000311:Adrenal Glands / Q000378:metabolism; D000818:Animals; D005786:Gene Expression Regulation / Q000187:drug effects*; D006624:Hippocampus / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010902:Pituitary Gland / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis*; D017472:Receptors, Interleukin-1 / Q000235:genetics*; D013737:Testis / Q000378:metabolism
D008070:Lipopolysaccharides; D012333:RNA, Messenger; D017472:Receptors, Interleukin-1