Deoxycorticosterone stimulates the activity of nicotinamide adenine dinucleotide phosphate-diaphorase/nitric oxide synthase immunoreactivity in hypothalamic nuclei of rats.
Mineralocorticoids (MC) play an important role in development of salt appetite. Part of this effect involves the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei, in which MC treatment increases arginine vasopressin (AVP) synthesis and release. Since the AVP system is also modulated by nitric oxide (NO), we studied if deoxycorticosterone acetate (DOCA) treatment changed the number of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) active neurons and neuronal NO synthase (nNOS)-immunoreactive (IR) cells in the PVN and SON. After four injections of DOCA (10 mg/rat per day), rats developed a salt appetite and increased NADPH-d active and nNOS-IR neurons in both nuclei. A single DOCA injection did not change salt consumption or nNOS-IR cells, but increased the number of NADPH-d positive neurons in the PVN only. Therefore, while acute MC treatment stimulated the activity of pre-existing enzyme, chronic steroid treatment recruited additional neurons showing nNOS immunoreactivity/NADPH-d activity. These data suggest a role for NO produced in the PVN and SON in DOCA stimulatory effects on AVP mRNA and salt appetite.
Laboratory of Neuroendocrine Biochemistry, Instituto de Biologi;a y Medicina Experimental, Obligado 2490, 1428 Buenos Aires, Argentina.
Flavia E
FE
Saravia
Luciana
L
Pietranera
Analia
A
Lima
Paulina
P
Roig
Yanina
Y
Revsin
Alejandro F
AF
De Nicola
D000818:Animals; D003900:Desoxycorticosterone / Q000494:pharmacology*; D007032:Hypothalamus, Anterior / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D007150:Immunohistochemistry; D008297:Male; D009252:NADPH Dehydrogenase / Q000032:analysis* / Q000276:immunology; D009474:Neurons / Q000201:enzymology; D019001:Nitric Oxide Synthase / Q000032:analysis* / Q000276:immunology; D052248:Nitric Oxide Synthase Type I; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017673:Sodium Chloride, Dietary / Q000494:pharmacology
D017673:Sodium Chloride, Dietary; D003900:Desoxycorticosterone; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496322:Nos1 protein, rat; D009252:NADPH Dehydrogenase