الفهرس 
Endothelial physiologyOnly 14 pages are availabe for public view
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Abstract
The present study was planned to elucidate the effect of ovariectomy, and high fat diet feeding on endothelial function, which mimicks postmenopausal state, and to evaluate the efficiency of three suggested lines of treatment, namely caloric restriction, -lipoic acid (α-LA) administration and physical exercise, in ameliorating endothelial dysfunction in ovariectomized high fat diet-fed rats.
The study was performed on 140 female Wistar albino rats, allocated into 7 groups:
Group 1: Sham-operated normal diet-fed control group (n=19).
Rats in this group were subjected to all surgical procedures of ovariectomy except for removal of ovaries. After one week recovery of the operation, they were fed control diet formula for 14 weeks.
Group 2: Sham-operated high fat diet-fed group (n=18).
Rats in this group were subjected to all surgical procedures of ovariectomy except for removal of ovaries. After one week recovery, they were fed high fat diet formula for 14 weeks.
Group3: Ovariectomized normal diet-fed group (n= 19).
Rats in this group were subjected to bilateral ovariectomy, and were fed control diet formula for 14 weeks starting after one week recovery.
Group 4: Ovariectomized high fat diet-fed group(n=24 ).
Rats in this group were subjected to bilateral ovariectomy, and were fed high fat diet (butter rich) formula for 14 weeks, starting after one week recovery.
Groups 5-7, the treated groups, were all fed high fat diet for 6 weeks starting after one week recovery of the ovariectomy operation, the treatment regimen starting thereafter as follows:
Group 5: Caloric restriction-treated, ovariectomized high fat diet-fed group (n=15 )
Treatment regimen was based on caloric restriction for 8 weeks, being allowed 70% of food intake of controls. The 30 % caloric reduction was calculated from the daily energy intake average of the 2 preceding weeks in normally fed rats.
Group 6: Alpha-Lipoic Acid-treated, ovariectomized high fat diet-fed group (n=18 )
Rats in this group continued on high fat diet while receiving intraperitoneal injection of the antioxidant -lipoic acid (Thiotacid, Eva-Pharma), 100mg/kg BW for 8 weeks, 7days/week.
Group 7: Exercise-treated, ovariectomized high fat diet-fed group (n= 14 )
Rats in this group continued to receive high fat diet for 8 weeks while being subjected to the exercise regimen, which consisted of treadmill running, at treadmill velocity of 1m/min, 30 min/day, 5 days/week. Rats were trained for one week, 15 min/day, before starting the exercise regimen.
One day before sacrifice, the blood pressure was measured, and on the day of sacrifice the body weight and length were determined for body mass index (BMI) assessment. Blood samples were collected, and the separated plasma was used for determination of plasma levels of von willebrand factor (vWF), tissue factor pathway inhibitor (TFPI) and nitric oxide (NO), and, as well, for the estimation of lipid profile. Peri-renal fat was excised and weighed.
The encountered results showed that high fat (butter rich) diet feeding and ovariectomy resulted in significant increase in the BMI gain % , peri-renal fat weight together with dyslipidemia; evidenced by significant elevation of plasma triglycerides, total cholesterol, LDL-C and atherogenic index and decreased plasma HDL-C. In addition, both high fat diet feeding and ovariectomy resulted in endothelial dysfunction; evidenced by increased plasma vWF and TFPI levels and decreased plasma NO level, accompanied by significant elevation of systolic, diastolic and mean arterial blood pressure, as well as the pulse pressure values.
30% caloric reduction, α-LA administration and exercise performance all resulted in decreased BMI gain %, plasma TG, LDL-C and atherogenic index, and elevated plasma HDL-C levels. Moreover, endothelial markers were markedly improved, with significant reduction in both plasma vWF and TFPI levels and significant increase in plasma NO level. Also, the systolic, diastolic and mean blood pressure and pulse pressure values were all reduced in treated groups. The peri-renal fat weight was only reduced in the caloric restriction-treated group.
However, the recorded values of the different studied variables in the different treated groups did not reach the matching values in the sham-operated normal diet-fed control group.
It could, thus, be concluded that estrogen deficiency states, as in postmenopausal females, and high fat diet feeding are associated with BMI gain, dyslipidemia, endothelial dysfunction and elevated blood pressure, the effects becoming more marked in high fat diet-fed, estrogen deficient females. Caloric restriction, α-LA administration or exercise could partially improve the changes, thereby ameliorating endothelial dysfunction and all its consequences.
The present data support the non-pharmacological concept of improving endothelial dysfunction.