Dioxin exposure down-regulates nitric oxide synthase and NADPH-diaphorase activities in the hypothalamus of Long-Evans rat.
In this study, we investigated the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) gastric administration on the expression of neuronal nitric oxide synthase (nNOS) and the NADPH-diaphorase (NADPH-d) activities in the brain of the Long-Evans rat. A single dose of TCDD (dissolved in olive oil, 50 microg/kg) or olive oil alone was administered to the rats by gavage. nNOS Western blotting experiment indicated a marked decrease in nNOS immunoreactivity at 1 and 2 weeks after TCDD treatment. NADPH-d histochemistry results showed a marked decrease in the number of NADPH-d stained cell bodies in the paraventricular hypothalamic nucleus, lateral hypothalamic area and perifornical nucleus in the TCDD-treated rats. The present study suggests that TCDD administration down-regulates nitric oxide product in the hypothalamus, which may be partially responsible for TCDD-induced feeding inhibition.
Cheng
Shi-Bin
SB
Department of Anatomy, Faculty of Medicine, Kagoshima University, Sakuragaoka 8-35-1, Japan.
Kuchiiwa
Satoshi
S
Ren
Xiao-Qin
XQ
Gao
Hong-Zhi
HZ
Kuchiiwa
Toshiko
T
Nakagawa
Shiro
S
D000818:Animals; D015536:Down-Regulation; D004785:Environmental Pollutants / Q000009:adverse effects*; D007031:Hypothalamus / Q000187:drug effects* / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D009252:NADPH Dehydrogenase / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000096:biosynthesis*; D052248:Nitric Oxide Synthase Type I; D000072317:Polychlorinated Dibenzodioxins / Q000009:adverse effects*; D051381:Rats; D020318:Rats, Long-Evans
D004785:Environmental Pollutants; D000072317:Polychlorinated Dibenzodioxins; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496322:Nos1 protein, rat; D009252:NADPH Dehydrogenase