Induction of the galanin-like peptide gene expression in the posterior pituitary gland after acute osmotic stimulus in rats.
Galanin-like peptide (GALP) is a 60 amino-acid peptide, and the GALP mRNA is restricted to pituicytes in the posterior pituitary gland (PP) and neurons in the hypothalamic arcuate nucleus (Arc). We examined whether the GALP gene expression in the PP and Arc would be induced after intraperitoneal (i.p.) administration of hypertonic saline, that is, acute osmotic stimulus, in rats. The dose-response (2.8, 4.5, 6.0 and 9.0% NaCl) and time-course (6.0% NaCl, 1, 3, 6, 12 and 24h) effects of acute osmotic stimulus on GALP mRNA levels in the PP and Arc were examined in rats by using in situ hybridization histochemistry. Plasma osmolality and plasma sodium concentration increased significantly at 1h, and returned to control level at 6h after i.p. administration of hypertonic saline (6.0% NaCl). The GALP mRNA level in the PP increased significantly 3 and 6h after i.p. administration of hypertonic saline (6.0% NaCl), but the level in the Arc did not change. These results showed that acute osmotic stimulus-induced GALP gene expression in the pituicyte of the PP, but not in the neurons in the Arc, and the gene expression in the pituicyte might be regulated by plasma osmolality and/or plasma sodium concentration.
Kawasaki
Makoto
M
Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan.
Saito
Jun
J
Hashimoto
Hirofumi
H
Suzuki
Hitoshi
H
Otsubo
Hiroki
H
Fujihara
Hiroaki
H
Ohnishi
Hideo
H
Nakamura
Toshitaka
T
Ueta
Yoichi
Y
D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000187:drug effects / Q000378:metabolism; D044089:Galanin-Like Peptide / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics*; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D009994:Osmolar Concentration; D009997:Osmotic Pressure / Q000187:drug effects; D010904:Pituitary Gland, Posterior / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012462:Saline Solution, Hypertonic / Q000494:pharmacology; D012964:Sodium / Q000097:blood; D014882:Water-Electrolyte Balance / Q000187:drug effects / Q000502:physiology*
D044089:Galanin-Like Peptide; D012333:RNA, Messenger; D012462:Saline Solution, Hypertonic; D012964:Sodium