Sensitivity to noradrenaline and electrical stimulation decreases with age in the rat tail artery

We have studied vasoconstrictor responses to noradrenaline and electrical field stimulation in the isolated perfused/superfused tail arteries of rats of 6-7, 16-17 and 30-31 months of age. Maximal vasoconstrictor responses to noradrenaline were the same at all three ages. Sensitivity to noradrenaline and to electrical stimulation were reduced in the 16-17 and 30-31 month old rats. The noradrenaline content of the arteries of the two latter age groups was reduced. We conclude that aging in this resistance vessel is accompanied by a decrease in the arterial noradrenaline content and in the sensitivity of the artery to noradrenaline.