Elevated levels of endothelin-1 and prostaglandin E2 and their effect over nitric oxide generation in placental tissue from neonatal streptozotocin induced diabetic rats.

CAPOBIANCO EVANGELINA; JAWERBAUM ALICIA; WHITE VERÓNICA; PUSTOVRH CAROLINA; SINNER DÉBORA; GONZÁLEZ ELIDA

PROSTAGLANDINS LEUKOTRIENES AND ESSENTIAL FATTY ACIDS

CHURCHILL LIVINGSTONE

Lugar: Edimburgo; Año: 2003 vol. 68 p. 225 - 231

0952-3278

Endothelin-1 (ET-1), nitric oxide (NO) and prostaglandin E2 (PGE2) are regulators of feto-placental hemodynamics. In this study we explore the inter-regulatory pathways that modulate the levels of these vasoactive agents in control and neonatal streptozotocininduced (n-stz) diabetic rat placenta. ET-1 levels are increased in diabetic placenta when compared to controls (p<0.001), and are strongly reduced by an NO inhibitor (p<0.001). PGE2 production is increased in diabetic placenta when compared to controls (p<0.01), but these levels are not modulated by ET-1. NO levels, similar in control and in diabetic placenta, are not influenced by PGE2, but they are negatively modulated by ET-1 in both control (p<0.05) and diabetic (p<0.01) placenta. We conclude that rat placental ET-1 inhibits NO levels but does not modify PGE2 concentrations. The elevated levels of ET-1 and PGE2 in diabetic placenta, potent vasoconstrictor of placental vasculature, are probably related to the induction of placental insufficiency and fetal hypoxia in this pathology.