Document Details

Document Type : Thesis 
Document Title :
POTENTIAL PROTECTIVE EFFECT OF VITAMIN D ON CARDIAC APOPTOSIS IN OBESE RATS.
التأثير الوقائي لفيتامين د على الموت المبرمج لعضلة القلب في فئران مصابة بالسمنة
 
Subject : Faculty of Medicine 
Document Language : Arabic 
Abstract : Background: Both diet quality and vitamin D status are important factors associated with many cardiovascular risk factors. Cardiac apoptosis has been associated to proinflammatory cytokines and oxidative stress, while implications of uncoupling proteins (UCPs) in cardiac apoptosis was not much investigated and the effects of long-term high fat diet (HFD) consumption on cardiac uncoupling proteins (UCPs) was not previously examined according to the available literature. The current work aimed to assess the effect of chronic consumption of HFD on the cardiac markers of; both apoptotic pathways, inflammatory and oxidative stresses and mitochondrial uncoupling and whether vitamin D supplementation with HFD would alter the expression of these markers. Materials and methods: 30 rats were divided into the following groups: Group I: Control, received the standard diet (10%fat) for 3 months (n= 5). Group II: received the standard diet for 3 months with vitamin D 400 IU/kg/day oral gavage (n=5). Group III: received HFD (45% fat) for 3 months (n=10), Group IV: received HFD for 3 months with vitamin D 400 IU/kg/day oral gavage (n=10). Another 30 rats were divided into the same previous groups, but the duration was extended to 6 months. Body weight and BMI were assessed at the start, every 45 days and at the end of the experiment. At the end of the experiment, blood samples were collected and sera were used to measure levels of total Cholesterol (TC), LDL, HDL, triglycerides, calcium and cortisol. Rats were sacrificed by decapitation under diethyl ether and heart specimens were preserved in RNA later for the quantitative real-time RT-PCR assessments. Results: TNF was highly expressed in the hearts of HFD group and treatment of vitamin D decreased TNF expression towards the control group. MDA was significantly up-regulated in hearts of HFD fed rats while it got significantly down-regulated in response to vitamin D supplementation with the HFD. Also, HFD feeding increased Fas-L expression in the cardiac tissue while, vitamin D supplementation with HFD reduced the expression of both Fas and Fas-L towards control levels. Moreover, the BAX gene was highly expressed in HFD fed rats for 6 months and an up-regulation of BCL2 and down regulation of BAX was observed in rats fed HFD with vitamin D. The present findings revealed significant up-regulation of UCP2 following 3 months of HFD, this up-regulation got reversed after more 3 months of continuous HFD. On the contrary, UCP3 showed persistent up-regulation in response to HFD at the end of both 3 and 6 months compared to control rats. Vitamin D supplementation with HFD brought expression levels of both UCP2 and 3 towards control levels at the end of the experiment. Conclusion: The present findings confirm the negative impact of HFD ingestion on cardiomyocytes and the beneficial effects of vitamin D supplementation on apoptotic, inflammatory and oxidative markers. The current work highlighted two novel findings; the effect of long term HFD consumption on cardiac expression of UCP 2&3 and their downregulation in response to vitamin D supplementation. The current observations expand our knowledge concerning the cardiac beneficial effects of vitamin D against chronic consumption of HFD. Future studies are required to establish the possible association between vitamin D status and cardiac mitochondrial uncoupling. 
Supervisor : Prof. Dr. Zienab Alrefaie 
Thesis Type : Doctorate Thesis 
Publishing Year : 1440 AH
2019 AD 
Added Date : Thursday, May 9, 2019 

Researchers

Researcher Name (Arabic)Researcher Name (English)Researcher TypeDr GradeEmail
خديجة مسعد السلميALSOLAMI, KHADEEJAH MESAIDResearcherDoctorate 

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