Hypertension: increase of collagen biosynthesis in arteries but not in veins.

In two models of hypertension in rats, it was shown that collagen synthesis and deposition are increased in arteries where blood pressure is elevated. By contrast, there were no alterations in any of the markers of collagen synthesis in veins, where blood pressure was only slightly elevated. It would appear that the stimulus for vascular collagen synthesis is provided by a direct effect of the increased pressure on the arterial cells rather than by a humoral factor released into the general circulation.