Downregulation of prolactin-releasing peptide gene expression in the hypothalamus and brainstem of diabetic rats.
We investigated the prolactin-releasing peptide (PrRP) mRNA levels in the hypothalamus and brainstem of streptozotocin (STZ)-induced diabetic rats and fa/fa Zucker diabetic rats, using in situ hybridization histochemistry. PrRP mRNA levels in the hypothalamus and brainstem of STZ-induced diabetic rats were significantly reduced in comparison with those of control rats. PrRP mRNA levels in the diabetic rats were reversed by both insulin and leptin. PrRP mRNA levels in the fa/fa diabetic rats were significantly reduced in comparison with those of Fa/? rats. PrRP mRNA levels in the fa/fa diabetic rats were significantly increased by insulin-treatment, but did not reach control levels in the Fa/? rats. We also investigated the effect of restraint stress on PrRP mRNA levels in STZ-induced diabetic rats. The PrRP mRNA levels in the control and the STZ-induced diabetic rats increased significantly after restraint stress. The diabetic condition and insulin-treatment may affect the regulation of PrRP gene expression via leptin and other factors, such as plasma glucose level. The diabetic condition may not impair the role of PrRP as a stress mediator.
Mera
Takashi
T
Department of Physiology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan.
Fujihara
Hiroaki
H
Saito
Jun
J
Kawasaki
Makoto
M
Hashimoto
Hirofumi
H
Saito
Takeshi
T
Shibata
Minori
M
Onaka
Tatsushi
T
Tanaka
Yoshiya
Y
Oka
Takakazu
T
Tsuji
Sadatoshi
S
Ueta
Yoichi
Y
D000818:Animals; D001933:Brain Stem / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism; D004302:Dorsomedial Hypothalamic Nucleus / Q000378:metabolism; D015536:Down-Regulation; D007028:Hypothalamic Hormones / Q000235:genetics*; D007031:Hypothalamus / Q000378:metabolism*; D017403:In Situ Hybridization; D007328:Insulin / Q000494:pharmacology; D020738:Leptin / Q000494:pharmacology; D008297:Male; D008526:Medulla Oblongata / Q000378:metabolism; D009479:Neuropeptides / Q000235:genetics*; D009765:Obesity / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism; D056690:Prolactin-Releasing Hormone; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011924:Rats, Zucker; D012149:Restraint, Physical / Q000009:adverse effects / Q000502:physiology; D017552:Solitary Nucleus / Q000378:metabolism
D007028:Hypothalamic Hormones; D007328:Insulin; D020738:Leptin; D009479:Neuropeptides; C534379:Prlh protein, rat; D056690:Prolactin-Releasing Hormone; D012333:RNA, Messenger