UP-REGULATION OF NEURONAL NOS MESSENGER-RNA IN THE PVN AND SON OF INHERITED DIABETES-INSIPIDUS RATS

WE investigated the expression of neuronal nitric oxide synthase (nNOS ) gene in the paraventricular (PVN) and supraoptic nuclei (SON) of rat s with inherited diabetes insipidus (DI), using in situ hybridization histochemistry. The DI rats showed hypo-osmotic polyuria and polydipsi a with arginine vasopressin (AVP) deficiency. The expression of nNOS g ene in the PVN and SON in homozygous (di/di) rats was significantly in creased in comparison to normal Wistar and heterozygous (di/+) rats. n NOS gene-expressing cells were distributed throughout the PVN and SON, including the divisions of AVP and oxytocin gene expressing cells in di/di rats. These results suggest that the expression of nNOS gene is upregulated in the magnocellular neurons in the PVN and SON of inherit ed DI rats.