Stimulation of Vascular Glycosaminoglycan Synthesis by Subpressor Angiotensin II in Rats

    loading  Checking for direct PDF access through Ovid


The vascular trophic effects of angiotensin II (Ang II) in small doses may precede its hypertension-producing effect, and de novo synthesis of components of extracellular matrix may be a requirement for Ang II-stimulated growth. In the present study, therefore, the incorporation of 35SC4 into glycosaminoglycans (synthesis) of aorta and bladder wall of young adult, male Sprague-Dawley rats was measured ex vivo after 48 hours of Ang II administration at two dose levels, 100 and 200 ng · kg−1 · min−1 IP. Vehicle-infused rats served as controls. Compared with controls, systolic blood pressure was unchanged in rats receiving 100 ng · kg−1 · min−1 Ang II and rose by 13 mm Hg (P<.05) in rats receiving the 200- ng · kg−1 · rain−1 dose. In Ang II-treated rats, glycosaminoglycan synthesis of the aorta was increased by 20% (P<.05) and 52% (p<.005) at the two dose levels, respectively. Glycosaminoglycan synthesis of bladder smooth muscle was also increased in Ang II-treated rats (P<.01), but the response was not dose dependent. By 7 to 10 days of Ang II administration (200 ng · kg−1 · min−1), glycosaminoglycan synthesis of aorta returned toward baseline (P<.10, >.05). The rate of synthesis of subtypes of glycosaminogrycans in the aorta was proportionately increased by Ang II. The early occurrence, magnitude, and arterial pressure independence of Ang H-induced glycosaminoglycan synthesis suggest that restructuring of extracellular matrix may play an important role in both the trophic and hypertension-producing action of Ang II.

Related Topics

    loading  Loading Related Articles