Collagen in the aortae of spontaneously hypertensive (SHR) rats

A biphasic pattern of collagen biosynthesis was found in the aortae of spontaneously hypertensive (SHR) rats; the time course of the rate of biosynthesis is similar to that described in the heart by Sen and Bumpus. In comparison to age-matched controls, collagen biosynthesis is elevated in the SHR rats, diminishes during the first fourteen weeks and rises again at the stage of established hypertension. In the period of established hypertension, the increased rate of collagen biosynthesis was associated with a pronounced rise of the collagen type I to type III ratio. On the other hand, in the pre-hypertensive stage, the proportion of collagen type III clearly exceeds the proportion of collagen type I in SHR rats.