Angiotensin II and catecholamines increase plasma levels of 8-epi-prostaglandin F(2alpha) with different pressor dependencies in rats.

نویسندگان

  • Toru Aizawa
  • Nobukazu Ishizaka
  • Shin-Ichi Usui
  • Noriko Ohashi
  • Minoru Ohno
  • Ryozo Nagai
چکیده

We investigated the extent of oxidative stress evoked in the hypertensive rat by measuring plasma levels of 8-epi-prostaglandin F(2alpha) (8-epi-PGF(2alpha)), a marker of in vivo oxidative stress. Administration of angiotensin (Ang) II and norepinephrine at doses of 0.7 and 2.8 mg. kg(-1). d(-1), respectively, resulted in similar significant elevations in plasma levels of 8-epi-PGF(2alpha). A 7-day infusion of Ang II at a nonpressor dose, but not norepinephrine at a nonpressor dose, also increased plasma levels of 8-epi-PGF(2alpha). The norepinephrine-induced increase in 8-epi-PGF(2alpha) levels could be completely normalized by 3 different classes of antihypertensive drugs: prazosin, an alpha-adrenergic receptor blocker; hydralazine, a nonspecific vasodilator; and losartan, a specific angiotensin type 1 (AT(1)) receptor antagonist. This finding suggests that the norepinephrine-induced increase is a pressor-dependent event. In contrast, among these antihypertensive drugs, only losartan was effective in inhibiting the Ang II-induced increase in plasma 8-epi-PGF(2alpha), suggesting that Ang II increases plasma levels of 8-epi-PGF(2alpha) in both a pressor-independent and an AT(1) receptor-dependent manner. In summary, continuous infusion of both Ang II and norepinephrine potently increases plasma levels of 8-epi-PGF(2alpha) and thus in vivo oxidative stress. Ang II and norepinephrine seem to induce this increase in 8-epi-PGF(2alpha) via mechanisms with different pressor dependencies.

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Angiotensin II and Catecholamines Increase Plasma Levels of 8-Epi-Prostaglandin F2 With Different Pressor Dependencies in Rats

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عنوان ژورنال:
  • Hypertension

دوره 39 1  شماره 

صفحات  -

تاریخ انتشار 2002