info:eu-repo/semantics/article
Role of nitric oxide in the metabolism of arachidonic acid in the rat anterior pituitary gland
Fecha
2001-02Registro en:
Velardez, Miguel Omar; Ogando, Diego; Franchi, Ana Maria; Duvilanski, Beatriz Haydee; Role of nitric oxide in the metabolism of arachidonic acid in the rat anterior pituitary gland; Elsevier Ireland; Molecular and Cellular Endocrinology; 172; 1-2; 2-2001; 7-12
0303-7207
CONICET Digital
CONICET
Autor
Velardez, Miguel Omar
Ogando, Diego
Franchi, Ana Maria
Duvilanski, Beatriz Haydee
Resumen
Nitric oxide (NO) affects cyclooxygenase (COX) and lipooxygenase (LOX) activities in several tissues. The aim of this study was to investigate the effect of NO on the AA metabolism in the anterior pituitary. LOX and COX products from anterior pituitaries of Wistar male rats were determined by [14C]-AA radioconversion method. Sodium nitroprusside (NP, 0.5 mM) and DETA NONOate (1 mM), NO donors, decreased 5-hydroxy-5,8,11,14-eicosatetraenoic acid (5-HETE) synthesis (P<0.05), effects that were reversed by hemoglobin. L-arginine also inhibited LOX activity. To the contrary, the inhibition of NO synthase by L-NAME (0.5 mM) or aminoguanidine (0.5 mM) increased 5-HETE production (P<0.05). COX activity was slightly stimulated by NP and L-arginine. However, DETA NONOate induced a stimulation of the synthesis of all prostanoids (P<0.05), this effect being reversed by hemoglobin. Neither NOS inhibitors nor hemoglobin modified basal prostanoids synthesis. These results indicate that NO inhibits LOX activity and stimulates COX activity in the anterior pituitary gland. The inhibition of LOX by NO may be another mechanism involved in the effects of NO on hormone release in the anterior pituitary.