Browsing by Subject "Fetal programming"

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    COX2 inhibition during nephrogenic period induces ANG II hypertension and sex-dependent changes in renal function during aging
    (American Physiological Society, 2014-03-01) Reverte, Virginia; Tapia, Antonio; Loria, Analia; Salazar, Francisco; Llinas Más, María Teresa; Salazar, Francisco Javier; Fisiología
    This study was performed to test the hypothesis that ANG II contributes to the hypertension and renal functional alterations induced by a decrease of COX2 activity during the nephrogenic period. It was also examined whether renal functional reserve and renal response to volume overload and high sodium intake are reduced in 3–4- and 9–11-mo-old male and female rats treated with vehicle or a COX2 inhibitor during nephrogenic period (COX2np). Our data show that this COX2 inhibition induces an ANG II-dependent hypertension that is similar in male and female rats. Renal functional reserve is reduced in COX2np-treated rats since their renal response to an increase in plasma amino acids levels is abolished, and their renal ability to eliminate a sodium load is impaired (P < 0.05). This reduction in renal excretory ability is similar in both sexes during aging but does not induce the development of a sodium-sensitive hypertension. However, the prolonged high-sodium intake at 9–11 mo of age leads to a greater proteinuria in male than in female (114 ± 12 μg/min vs. 72 ± 8 μg/min; P < 0.05) COX2np-treated rats. Renal hemodynamic sensitivity to acute increments in ANG II is unaltered in both sexes and at both ages in COX2np-treated rats. In summary, these results indicate that the reduction of COX2 activity during nephrogenic period programs for the development of an ANG II-dependent hypertension, reduces renal functional reserve to a similar extent in both sexes, and increases proteinuria in males but not in females when there is a prolonged increment in sodium intake.
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    Role of angiotensin II in arterial pressure and renal hemodynamics in rats with altered renal development: age- and sex-dependent differences
    (2013-01-01) Reverte, Virginia; Tapia, Antonio; Baile, Goretti; Gambini, Juan; Giménez, Ignacio; Llinas, María Teresa; Salazar, F. Javier; Fisiología
    Numerous studies have demonstrated that angiotensin II (ANG II) is involved in hypertension and renal changes occurring as a consequence of an adverse event during renal development. However, it was unknown whether this involvement is sex and age dependent. This study examines whether the increments in arterial pressure (AP) and in the renal sensitivity to ANG II are sex and age dependent in rats with altered renal development. It also evaluates whether the ANG II effects are accompanied by increments in AT1 receptors and oxidative stress. Experiments were performed in 3- to 4- and 10- to 11-mo-old rats treated with vehicle or an AT1 receptor antagonist (ARAnp) during the nephrogenic period. ARAnp-treated rats were hypertensive, but an age-dependent rise in AP was only found in males. Three days of treatment with candesartan (7 mg·kg−1·day−1) led to a fall of AP that was greater (P < 0.05) in male than in female 10- to 11-mo-old ARAnp-treated rats. Oxidated proteins were elevated (P < 0.05), and the decrease in AP elicited by candesartan was reduced (P < 0.05) when these rats are also treated with tempol (18 mg·kg−1·day−1). Hypertension was not maintained by an elevation of AT1 receptors in kidneys and mesenteric arteries. The acute renal hemodynamic response to ANG II (30 ng·kg−1·min−1) was similarly enhanced (P < 0.05) in both sexes of ARAnp-treated rats at 3–4 but not at 10–11 mo of age. Our results suggest that an adverse event during the nephrogenic period induces an ANG II-dependent increment in AP that is aggravated only in males during aging and that oxidative stress but not an increase in AT1 receptor contributes to the rise in AP. This study also shows that the renal hemodynamic sensitivity to ANG II is transitorily enhanced in both sexes of rats with altered renal development.