RESUMEN
BACKGROUND: Alzheimer's disease (AD) is a progressive neurodegenerative disease in which endothelial cell (EC) can be affected. In brain, functional changes in ECs contribute to reductions in resting blood flow. Furthermore, angiotensin-converting enzyme inhibitors (ACE-I) have beneficial effects on endothelial dysfunction. This is the first study that presents direct experimental evidence associating endothelial apoptosis as a basis of AD pathogenesis and response to an ACE-I therapy. MATERIALS AND METHODS: Human umbilical vein ECs (HUVECs) were treated with sera from AD patients and sera from healthy volunteers (each group, n = 10). Apoptosis was determined by annexin V-propidium iodide staining and cell death detection kit. The effect of 50 µM enalapril on endothelial apoptosis was assessed. Nitrite (NO2 (-)) levels were determined in the culture supernatants. RESULTS: Enalapril suppressed the induction of apoptosis by the serum of patients only when used before treating HUVECs with the sera of AD. Mean ± SD of apoptosis induction in the control group was 6.7 ± 3.69; in the group treated with sera of AD for 24 h was 47.78 ± 0.65; in the group wherein sera from AD was added (pretreatment) after exposure of HUVECs by 50 µM enalapril for 24 h was 26.6 ± 2.63; and in the group wherein HUVECs were exposed in the sera of AD for 24 h and then 50 µM enalapril was added to these cells for another 24 h (post-treatment) was 56.87 ± 5.51. Also, the mean ± SD of NO2 (-) concentration showed significantly greater levels of dissolved NO2/NO3 metabolite in the culture media of untreated HUVECs by enalapril (1.03 ± 0.06) as compared with control (0.26 ± 0.13; P < 0.05), while the rate of nitric oxide (NO) significantly decreased when enalapril was presented in culture both in the pretreatment (0.07 ± 0.003) and in the post-treatment group (0.06 ± 0.005; P < 0.05). CONCLUSION: It could be concluded that EC treated with sera from AD patients activates apoptosis in HUVECs; this effect was reversed by enalapril pretreatment. This can be proposed as a therapeutic approach for Alzheimer's patients.
RESUMEN
BACKGROUND: There are increasing evidences of endothelial dysfunction in migraine. The ACE-inhibitors have previously been shown to be effective in migraine prophylaxis. Furthermore, ACE inhibitors have beneficial effects on endothelial dysfunction. We therefore investigated whether Enalapril is effective in endothelial function improvement. METHODS: In this randomized clinical trial, 10 mg Enalapril daily was compared with matched placebo in 40 patients with migraine for two months. Flow Mediated Dilation (FMD), serum total nitrite and C-reactive protein (CRP) were measured in all patients at the baseline and after 2 months. RESULTS: patients' FMD increased in the case group after treatment with Enalapril (p = 0.002) while there was no significant change in control group. Total nitrite concentration increased in case group (p = 0.000), while there was no significant difference before treatment. There was no significant difference in the CRP concentrations in two groups. CONCLUSIONS: These results indicate that ACE inhibition can improve endothelial function in patients with migraine, as it has been shown by both FMD and serum levels of nitric oxide. The mechanism could be either that Enalapril limits the angiotensin IIinduced production of superoxide radicals which would normally inactivate nitric oxide, or that it may increase bradykinin-mediated nitric oxide release.