Induction of galanin-like peptide gene expression in the arcuate nucleus of the rat after acute but not chronic inflammatory stress.
Galanin-like peptide (GALP) has been recently isolated from the porcine hypothalamus. The GALP mRNA is restricted to neurons in the hypothalamic arcuate nucleus (Arc) and pituicytes in the posterior pituitary gland (PP), but physiological functions of the GALP remains unclear in both areas. We examined the effects of acute and chronic inflammatory stresses on the GALP mRNA levels in the rat Arc using in situ hybridization histochemistry. Intraperitoneal (i.p.) injection of bacterial endotoxin lipopolysaccharide (LPS) caused a marked increase of the GALP mRNA levels in the Arc. The effects of i.p. injection of LPS on the GALP mRNA levels in the Arc were significantly attenuated by pretreatment with i.p. injection of indomethacin cyclooxygenase inhibitor. Adjuvant arthritis caused by subcutaneous (s.c.) injection of heat-killed Mycobacterium butyricum as chronic inflammatory stress did not affect the GALP mRNA levels in the Arc, though the GALP mRNA levels in the pituicytes of the PP were markedly increased by two peaks at 12 h and 15 days after s.c. injection of heat-killed M. butyricum. Enzymeimmunoassay showed that the plasma concentration of GALP was not affected by these inflammatory stresses. These results suggest that acute inflammatory stress might be a potent stimulant to increase the GALP mRNA levels in the Arc of the rat via synthesis of prostaglandins.
Saito
Jun
J
Department of Physiology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan.
Ozaki
Yumi
Y
Kawasaki
Makoto
M
Ohnishi
Hideo
H
Okimoto
Nobukazu
N
Nakamura
Toshitaka
T
Ueta
Yoichi
Y
D000704:Analysis of Variance; D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D001831:Body Temperature / Q000187:drug effects; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004347:Drug Interactions; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D044089:Galanin-Like Peptide / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D017403:In Situ Hybridization / Q000379:methods; D007213:Indomethacin / Q000494:pharmacology; D007249:Inflammation / Q000139:chemically induced / Q000378:metabolism* / Q000382:microbiology / Q000517:prevention & control; D008070:Lipopolysaccharides / Q000633:toxicity; D008297:Male; D009161:Mycobacterium / Q000472:pathogenicity; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011917:Rats, Inbred Lew; D017208:Rats, Wistar; D013997:Time Factors
D016861:Cyclooxygenase Inhibitors; D044089:Galanin-Like Peptide; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D007213:Indomethacin