In utero sFlt-1 exposure differentially affects gene expression patterns in fetal liver.

The soluble fms-like tyrosine kinase factor 1 (sFlt-1) is a major contributor to antiangiogenesis during preeclampsia. However, little is known about the effects of sFlt-1 on fetal health. In this study we aim to evaluate the effects of the sFlt-1 concentration during pregnancy on fetal liver physiology. We used adenoviral gene delivery in Sprague-Dawley dams (seven females, 10 weeks old) during mid-gestation (gestational day 8) with adenovirus overexpressing sFlt-1, and age-matched controls (six females, 10 weeks old) with empty adenoviral virus in order to quantify the sFlt-1 concentrations in pregnant dams. Dams exposed to adenoviral sFlt-1 delivery were subdivided into a low (n=4) and high sFlt-1 (n=3) group based on host response to the virus. One-way analysis of variance showed that fetuses (five per dam) exposed to high sFlt-1 concentrations in utero show fetal growth restriction (1.84±0.043 g high sFlt-1 v. 2.32±0.036 g control; mean (M)±s.e.m.; P<0.001), without hypertension or proteinuria in the dams. In continuation, the microarray analysis of the fetal liver of the high sFlt-1 group showed significant enrichment of key genes for fatty acid metabolism and Ppara targets. In addition, using pyrosequencing, we found that the Ppara enrichment in the high sFlt-1 group is accompanied by decreased methylation of its promoter (1.89±0.097 mean % methylation in high sFlt-1 v. 2.26±0.095 mean % methylation in control, M±s.e.m., P<0.02). Our data show that high sFlt-1 concentrations during pregnancy have detrimental effects on the fatty acid metabolism genes and the Ppara targets in the fetal liver.

Hydrogen sulfide producing enzymes in pregnancy and preeclampsia.

Preeclampsia, a human pregnancy specific disorder is characterized by an anti-angiogenic state. As hydrogen sulfide (H(2)S) has pro-angiogenic and anti-oxidative characteristics, we hypothesized that H(2)S levels could play a role in the pathogenesis of preeclampsia and studied the placental expression of the H(2)S-producing enzymes cystathionine-γ-lyase (CSE) and cystathionine-ß-synthase (CBS). CBS and CSE protein are expressed in the fetal-placental endothelium and CBS only in Hofbauer cells. CBS mRNA expression is decreased (p = 0.002) in early-onset preeclampsia, while CSE mRNA is unchanged. Thus, down regulation of CBS during early-onset preeclampsia may result in less H(2)S-production and may aid in the anti-angiogenic state.

PP016. Circulating lymphangiogenic factors in preeclampsia.

INTRODUCTION: Preeclampsia, a human pregnancy specific disorder is characterized by an anti-angiogenic state due to high levels of circulating soluble vascular endothelial growth factor 1 (sVEGFR1). However, the role of lymphangiogenesis in preeclampsia has not been investigated. Recently, impaired VEGF-C (factor that regulates lymphangiogenesis) signalling has been implicated in the pathogenesis of interstitial edema and salt-sensitive hypertension. OBJECTIVES: Therefore, we hypothesized that circulating VEGF-C and its circulating receptors (sVEGFR2 and sVEGFR3) may also be altered in preeclampsia and correlate with the severity of the phenotype. METHODS: We analyzed plasma levels of VEGF-C, sVEGFR1, sVEGFR2 and sVEGFR3 in women with gestational hypertension (GHTN, n=20), preeclampsia (PE, n=20) and normotensive pregnancies (NP, n=20) in the third trimester and values reported as mean±SD in pg/ml. RESULTS: As previously reported, sVEGFR1 levels were significantly higher in subjects with PE (19938 ± 12973) than in GHTN (7156±5432), p<0.01 or NP (7760±6018), p<0.01. VEGF-C levels were lower in subjects with GHTN (676±323) than in PE (1335±625), p<0.01, but not statistically different than in NP (971±556), p=0.11. There was a trend towards lower sVEGFR-2 in PE as compared to GHTN or NP. Interestingly sVEGFR-3 was significantly lower in PE (54,371±21,107) as compared to NP (83,709±24,983), p<0.01, but not different as compared to GHTN (54,642±26,947). The ratio of sVEGFR-2+sVEGFR-3/VEGF-C was dramatically lower during PE (57±38) as compared to GHTN (113±72), p<0.01 or NP (133±91), p<0.01. CONCLUSION: Preeclampsia is characterized by circulating pro-lymphangiogenic state as evidenced by decreased sVEGFR-3, slightly decreased VEGFR-2, increased VEGF-C and a dramatically lower ratio of sVEGFR2+sVEGFR3/VEGF-C. Our data suggests that the circulating pro-lymphoangiogenic state during preeclampsia may be a compensatory response to edema and hypertension. Additional studies are needed to evaluate the clinical relevance of the altered lymphangiogenic signalling pathway during preeclampsia.

Combination of calcium channel blockers and beta-blockers for patients with exercise-induced angina pectoris: beneficial effect of calcium channel blockers largely determined by their effect on heart rate.

The combination of calcium channel blockers and beta-blockers is more effective for the treatment of exercise-induced angina pectoris than beta-blocker monotherapy. As ischemia in exercise-induced angina is essentially preceded by an increase in heart rate, calcium channel blockers with a negative chronotropic property may perform better for this purpose than nonchronotropic compounds. A 335-patient, 10-week, double-blind, parallel-group comparison of amlodipine 5 mg and 10 mg, diltiazem 200 mg and 300 mg, and mibefradil 50 mg and 100 mg treatment added to baseline beta-blocker treatment was performed. Exercise testing (ETT) was performed by bicycle ergometry. All of the calcium channels blockers significantly delayed the onset of 1 mm ST-segment depression on ETT (p < 0.001 for any treatment vs. baseline). In addition, mibefradil, in both low- and high-dose treatments, produced the largest delays (low dose: different from diltiazem and amlodipine by 24.1 and 29.8 seconds, respectively, p < 0.003 and < 0.001; high dose: different from diltiazem and amlodipine by 33.7 and 37.0 seconds, respectively, p < 0.001 and < 0.001). A stepwise logistic regression analysis revealed that this beneficial effect of calcium channel blockers was largely dependent on their effect on heart rate. Serious symptoms of dizziness likewise occurred significantly more frequently on mibefradil (p < 0.05 vs. diltiazem) and urged no fewer than 19 patients on mibefradil to withdraw from the trial. The authors conclude that calcium channel blockers with a negative chronotropic property provide a better delay of ischemia in patients with exercise-induced angina, but the concomitant risk of intolerable dizziness may reduce this benefit.

Value of the addition of amlodipine to atenolol in patients with angina pectoris despite adequate beta blockade.

Anginal patients who remain symptomatic despite optimally dosed beta blockade may also be given dihydropyridine calcium antagonists. This treatment regimen was examined in a double-blind parallel, randomized, controlled study in 147 patients with angina and positive bicycle exercise tests despite optimal beta blockade with atenolol (heart rate at rest <60 beats/min). Patients were randomized to atenolol and/or placebo (control), and atenolol and/or amlodipine. The main outcome measurement was exercise tolerance after 8 weeks compared with baseline. After 8 weeks, no significant differences in time to 0.1-mV ST-segment depression, time to chest pain, and time to end of exercise were observed. The number of patients with chest pain during exercise decreased significantly in the amlodipine group (p = 0.04 vs controls). The subgroup of patients with an early (<6 minutes) onset of chest pain at baseline showed a significant increase in time to chest pain after amlodipine (p = 0.0001 vs controls). In the amlodipine group, ST depression and rate-pressure product at submaximum comparable workload decreased to 0.4 mm (0.56) (p = 0.03 vs controls) and 1.223 (2.652) beats/ min x mm Hg (p = 0.01 vs controls). The number of patients in each group with adverse events was not different. The addition of amlodipine to the treatment of patients with myocardial ischemia, despite optimal beta blockade, is well tolerated and may lead to improvement in symptomatic anginal patients, who have a rapid onset of exercise-induced ischemia.

Anti-ischaemic efficacy of L-propionylcarnitine--a promising novel metabolic approach to ischaemia?

L-propionylcarnitine, a naturally occurring derivative of L-carnitine, essential for mitochondrial fatty acid transport and high-energy phosphate exchange, acutely reduces myocardial ischaemia and improves ischaemia-induced cardiac dysfunction following intravenous administration. This randomized, crossover study was designed to compare the long-term anti-ischaemic effects of oral L-propionylcarnitine with diltiazem in patients with stable, exercise-induced angina. After a 2-week washout phase of anti-anginal medication and a 2-week single-blind placebo period, 46 patients were included in the study, 23 of whom received 1500 mg L-propionylcarnitine daily for 6 weeks, and 23 diltiazem (180 mg daily for 3 weeks, followed by 360 mg daily for 3 weeks), crossing over to the other treatment after a 1-week washout period. Three patients on L-propionylcarnitine and two on diltiazem discontinued. Both treatments resulted in comparable exercise duration (582 +/- 35 s and 588 +/- 33 s, mean +/- SEM), time to 0.1 mV ST depression (436 +/- 38 s and 465 +/- 36 s), and increase in time to 0.1 mV ST depression from baseline (20% and 28%), L-propionylcarnitine and diltiazem, respectively. Diltiazem decreased the rate-pressure product at rest and exercise, L-propionylcarnitine did not. Both compounds significantly reduced ST depression at maximal exercise [23% (L-propionylcarnitine) vs 35% (diltiazem), P < 0.05 diltiazem vs L-propionylcarnitine]. Diltiazem increased the time to onset of angina by 22%. In contrast, no significant changes occurred with L-propionylcarnitine. During the study, anginal attacks were reduced by 70% and 57%, and nitroglycerin consumption decreased by 57% and 70%, L-propionylcarnitine and diltiazem, respectively. Thus, both L-propionylcarnitine and (high-dose) diltiazem result in anti-ischaemic effects and decrease anginal attacks in daily life. Although the effect of diltiazem on exercise-induced ischaemia appears more pronounced than that of L-propionylcarnitine, this novel metabolic approach to ischaemia warrants further development.

Efficacy and safety of benazepril plus hydrochlorothiazide versus benazepril alone in hypertensive patients unresponsive to benazepril monotherapy.

A combination of benazepril 10 mg plus hydrochlorothiazide 12.5 mg once daily was investigated in the treatment of patients with mild-to-moderate essential hypertension who had not responded to monotherapy with benazepril 10 mg. Patients failing to respond to 4 weeks of benazepril 10 mg/d were randomized to continue with the monotherapy (n = 47) or receive the combination therapy (n = 46). After 4 weeks of double-blind treatment, reductions in blood pressure were significantly greater among patients given the combination than among those receiving benazepril alone: a 4.7 +/- 1.5 mm Hg difference in mean sitting diastolic blood pressure was noted in favor of the combination therapy (P = 0.0037). The incidence of adverse events, particularly cough, was lower with benazepril + hydrochlorothiazide than with benazepril alone; no notable changes in body weight or heart rate were seen in either group.