Activation of hypothalamic neuronal nitric oxide synthase in lithium-induced diabetes insipidus rats.
The expression of the neuronal nitric oxide synthase (nNOS) gene in the paraventricular (PVN) and supraoptic nuclei (SON) in rats with lithium (Li)-induced polyuria was examined by using in situ hybridization histochemistry. The state of the thyroid axis in these rats was also examined by in situ hybridization histochemistry for thyrotropin-releasing hormone (TRH) and thyroid-stimulating hormone (TSH) mRNAs and radioimmunoassay for circulating thyroid hormones. Adult male Wistar rats consuming a diet that contained LiCl (60 mmol/kg) for 4 weeks developed remarkable polyuria. The urine in the Li-treated rats was hypotonic and had a large volume and low ionic concentration. The nNOS mRNA in the PVN and SON was significantly increased in the Li-treated rats in comparison with that in control. The increased levels of the nNOS mRNA in the PVN and SON were confirmed by NADPH-diaphorase histochemical staining. There were no differences of TRH mRNA in the PVN, TSH mRNA in the anterior pituitary and plasma concentrations of free T3 and free T4 between Li-treated rats and control rats. These results suggest that Li-induced diabetes insipidus may activate nNOS in the PVN and SON without change of the thyroid axis.
Anai
H
H
Second Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, 807-8555, Kitakyushu, Japan.
Ueta
Y
Y
Serino
R
R
Nomura
M
M
Nakashima
Y
Y
Yamashita
H
H
D000818:Animals; D018692:Antimanic Agents / Q000633:toxicity*; D003919:Diabetes Insipidus / Q000139:chemically induced* / Q000473:pathology; D004789:Enzyme Activation / Q000187:drug effects / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018021:Lithium Chloride / Q000633:toxicity*; D008297:Male; D019001:Nitric Oxide Synthase / Q000235:genetics*; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects* / Q000473:pathology; D011141:Polyuria / Q000139:chemically induced / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D013495:Supraoptic Nucleus / Q000187:drug effects* / Q000473:pathology
D018692:Antimanic Agents; D019001:Nitric Oxide Synthase; D018021:Lithium Chloride