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| Author(s): |
Matheus Augusto Callegari
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Botucatu. 2021-07-16. |
| Institution: | Universidade Estadual Paulista (Unesp). Faculdade de Medicina. Botucatu |
| Defense date: | 2021-06-23 |
| Advisor: | Sergio Alberto Rupp de Paiva |
| Abstract | |
Vitamin D (VitD) deficiency is considered a public health problem. As a consequence, health professionals have encouraged the supplementation of VitD. However, VitD has a biphasic dose-response curve in cardiovascular pathophysiology, and deficiencies and excesses can be harmful. A previous study conducted by our research group showed that VitD supplementation in excessive doses for 2 months in male Wistar rats resulted in a process that is aggressive to the heart through oxidative stress (OS). OS can activate different pathways depending on their intensity and duration. Thus, it is necessary to define which paths are involved in the process, as well as when the changes start. Another important question is whether these changes also occur in females, as the metabolism of VitD appears to be different between both sexes. The present work aimed to evaluate whether vitamin D supplementation leads to different cardiac changes in male and female rats and whether these are time-dependent. For this, 72 male Wistar rats and 72 female Wistar rats weighing approximately 250g and 200g, respectively, were used. The animals were allocated to receive standard chow without and with VitD supplementation (+10000 UI / kg of feed) and distributed into groups according to the duration of supplementation (20, 40, and 60 days). Therefore, 12 groups were formed (n = 12). After the experimental period, the animals were euthanized and the material was collected for analysis. The comparison between groups was made by three-factor ANOVA, taking into account the factors sex, supplementation, and time. There were differences between the sexes for body weight and feed intake which were higher in male animals. The biochemical evaluation showed that VitD supplementation promoted a time-dependent increase in serum calcium, but that it did not characterize hypercalcemia. In addition, the animals also presented higher values of heme oxygenase-1 and alteration in the behavior of proteins involved in the NF-kB pathway and cellular apoptosis. These data show that vitamin D supplementation in excessive doses leads to biochemical and molecular changes in the heart, probably due to medium OS intensity and that the supplementation time is an important factor for the observation of these changes. (AU) | |
| FAPESP's process: | 19/15581-5 - Influence of gender and time on cardiac remodeling induced by vitamin D supplementation |
| Grantee: | Matheus Augusto Callegari |
| Support Opportunities: | Scholarships in Brazil - Master |