LONG-TERM SUPPLEMENTATION WITH A HIGH CHOLESTEROL DIET DECREASES THE RELEASE OF ATP FROM THE CAUDAL ARTERY IN AGED RATS

We examined the effects of high cholesterol (HC) diet on the spontaneo us and noradrenaline-induced release of ATP, ADP, AMP and adenosine fr om caudal arteries and on the plasma levels of these adenyl purines in aged (100-week-old) Wistar rats. Administration of this diet for 12 w eeks significantly reduced spontaneous and noradrenaline (1 mu mol/L)- evoked release of adenyl purines from the caudal arteries relative to rats given the control diet The unsaturation index of fatty acids (UI) , which gives the average number of double bonds, of both the plasma a nd the caudal artery was significantly less in the HC diet-fed rats th an in those fed the control diet. The HC diet for 12 weeks produced a slight but significant increase in systolic and diastolic blood pressu re with advancing age. Regression analysis revealed a significant inve rse relationship between the total amount of purines released from the artery and diastolic blood pressure, and also a positive relationship between the total amount of purines released and the UI of the caudal artery. These results suggest that the high cholesterol diet decrease d the release of adenyl purines from the caudal arteries of aged rats, leading to an increase in blood pressure.