Effects of Melatonin and Pycnogenol on Small Artery Structure and Function in Spontaneously Hypertensive Rats
| Autor: | Daniele Avanzi, Caterina Platto, Francesca Bonomini, Luigi Fabrizio Rodella, Gianluca E.M. Boari, Damiano Rizzoni, Carolina De Ciuceis, Rita Rezzani, Silvia Paiardi, Annamaria Pilu, Enrico Agabiti Rosei, Enzo Porteri |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Male
medicine.medical_specialty Endothelium Systole medicine.disease_cause Rats Inbred WKY Melatonin Random Allocation Rats Inbred SHR Internal medicine In Situ Nick-End Labeling Internal Medicine medicine Animals oxidative stress cardiovascular diseases Endothelial dysfunction Antihypertensive Agents Probability Flavonoids Analysis of Variance biology Plant Extracts Chemistry Endothelial function medicine.disease Immunohistochemistry Mesenteric Arteries Rats Disease Models Animal Endocrinology Blood pressure medicine.anatomical_structure Cyclooxygenase 2 Pycnogenol Hypertension biology.protein Matrix Metalloproteinase 2 Vascular Resistance Endothelium Vascular Cyclooxygenase Nitric Oxide Synthase Biomarkers Acetylcholine Oxidative stress medicine.drug Myograph |
| Zdroj: | Hypertension. 55:1373-1380 |
| ISSN: | 1524-4563 0194-911X |
| Popis: | It was suggested that oxidative stress has a key role in the development of endothelial dysfunction, as well as microvascular structural alterations. Therefore, we have investigated 2 substances with antioxidant properties: melatonin and Pycnogenol. We treated 7 spontaneously hypertensive rats (SHRs) with melatonin and 7 with Pycnogenol for 6 weeks. We compared results obtained with those observed in 7 SHRs and 7 Wistar-Kyoto normotensive control rats kept untreated. Mesenteric small resistance arteries were dissected and mounted on a wire myograph, and a concentration-response curve to acetylcholine was performed. Aortic contents of metalloproteinase 2, Bax, inducible NO synthase, and cyclooxygenase 2 were evaluated, together with the aortic content of total collagen and collagen subtypes and apoptosis rate. A small reduction in systolic blood pressure was observed. A significant improvement in mesenteric small resistance artery structure and endothelial function was observed in rats treated with Pycnogenol and melatonin. Total aortic collagen content was significantly greater in untreated SHRs compared with Wistar-Kyoto control rats, whereas a full normalization was observed in treated rats. Apoptosis rate was increased in the aortas of untreated SHRs compared with Wistar-Kyoto control rats; an even more pronounced increase was observed in treated rats. Bax and metalloproteinase 2 expressions changed accordingly. Cyclooxygenase 2 and inducible NO synthase were more expressed in the aortas of untreated SHRs compared with Wistar-Kyoto control rats; this pattern was normalized by both treatments. In conclusion, our data suggest that treatment with Pycnogenol and melatonin may protect the vasculature, partly independent of blood pressure reduction, probably through their antioxidant effects. |
| Databáze: | OpenAIRE |
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