The effects of aqueous-alcoholic red grape seed extract on the knee joint blood flow in rats receiving lead

Chronic exposure to low amounts of lead causes hypertension in humans and experimental animals. The main objective of this study was to determine the effect of aqueous-alcoholic red grape seed extract (GSE) on the knee joint blood pressure and blood flow changes in rats receiving lead. Thirty two adult male Wistar rats were divided into four groups of 8 each. Group A (control) received ordinary feed and tap water. The other three groups received tap water containing 100 ppm lead acetate alone (group B)، GSE alone (100 mg/kg، orally، group C)، or 100 ppm lead acetate in drinking water + GSE (100 mg/kg، orally، group D) for 60 days. A laser Doppler flow-meter was used to measure changes in the blood flow. The responsiveness of blood vessels in the knee joint area to the different doses of sodium nitroprusside (SNP) (endothelium-independent vasorelaxant) was determined. The results indicated that chronic exposure to lead could increase blood pressure significantly (129. 12± 3. 3; p<0. 05) in rats. Consumption of GSE prevented the increase significantly (p<0. 001) in the group receiving lead and GSE (110. 2± 2. 1). SNP at a dose of10-4resulted inan increase in blood flow (22. 28 ±1. 89%) in the knee joint by increasing diameter of the vessels in the group receiving lead and in a reduction in blood pressure (p<0. 05). In addition، GSE prevented the lead from reducing blood flow in the knee joint in the group receiving (p<0. 05). Based on the result of this study، it can be concluded that grape seed extract can، through its strong antioxidant activity and eliminating free radicals، reduce blood pressure in rats receiving lead، thereby lessening its toxic effects.