Prenatal exposure to inflammation produces offspring that are hypertensive in adulthood. This study explored alterations of the renin-angiotensin system (RAS) during the development of hypertension induced by prenatal exposure to lipopolysaccharide (LPS). In addition, the effects of an inhibitor of the nuclear transcription factor (NF)-jB (pyrrolidine dithiocarbamate, PDTC) on this process were assessed. Pregnant rats were randomly divided into four groups (n¼8): a control group, an LPS group, a PDTC group and an LPS+PDTC group. The rats in these groups were intraperitoneally administered vehicle, 0.79 mg kg À1 LPS, 100 mg kg À1 PDTC or LPS plus PDTC, respectively. LPS was given on the 8th, 10th and 12th days, whereas PDTC was given from the 8th to the 14th day during gestation. At various ages from day 1 to 25 weeks, plasma renin activity, plasma angiotensin II (Ang II) levels, renal function, glomerular number, mRNA expression levels of renal cortex renin and angiotensin-converting enzyme (ACE), the number of Ang II-positive cells and NF-jB activation were determined. The results showed that prenatal exposure to LPS resulted in significantly lower glomerular numbers and creatinine clearance rates and higher urinary protein and renal cortex ACE mRNA expression in adult offspring. Prenatal LPS also decreased the renal cortex renin mRNA expression and the number of Ang II-positive cells in offspring at 1 day of age, but these increased at 7, 16 and 25 weeks, whereas the plasma renin activity and Ang II concentration remained unchanged. Simultaneously, PDTC treatment markedly reversed the action of LPS. In conclusion, prenatal exposure to LPS resulted in alteration of the intrarenal RAS and renal damage in adult offspring rats.
INTRODUCTIONThe effects of hypertension on the cardiovascular and renal systems are of major concern due to its morbidity and mortality. Though many efforts have been made to understand the pathophysiology of hypertension, it is still unclear because of its complexity. 1 A growing body of evidence indicates that hypertension is an inflammatory state wherein proinflammatory cytokines, such as tumor necrosis factor-a and interleukin-6, contribute to the hypertensive effect. 2-5 Angiotensin II (Ang II), the major biologically active component of the reninangiotensin system (RAS), not only induces vasoconstriction, aldosterone release and sodium reabsorption by the nephron, but is also intricately interrelated with inflammation. Furthermore, the association of Ang II and inflammation induces an amplification process that involves oxidative stress and proinflammatory transcription factors, leading to progressive vascular injury 6 and having an important role in the development of hypertension and target organ damage. 2 It has been shown in our laboratory that maternal exposure to lipopolysaccharide (LPS) results in hypertension in offspring rats. 7