Alterations of angiotensin II receptor levels in full-thickness excisional wounds in rat skin

Angiotensin II was recently shown to have a growth-promoting role after vascular injury and in the development of cardiac hypertrophy and fibrosis. In addition, angiotensin II may play a role in dermal wound repair. In this article, alterations in angiotensin II receptor levels in tissue harvested from full-thickness excisional dermal wounds in adult Sprague-Dawley rats were examined. A 2.25 cm² full-thickness excision of the dorsal skin was made under general anesthesia and the tissue was harvested on days 1, 3, 5, 7, and 10 after wounding. The level of ¹²⁵l-Sar¹.lle⁸-angiotensin II bound to membrane preparations of both granulation tissue and wound edge increased from day 1, peaked on day 5, and returned to nonsurgical levels by day 10. In both granulation and wound edge segments of the injured skin the maximum binding on postoperative day 5 was about twice that of postoperative day 1 tissue or control skin. Competitive binding studies with angiotensin II type 1 receptor or type 2 receptor antagonists (DuP 753 and CGP 42112B, respectively) showed that the receptors present in the healing dermal tissue from the adult rat were almost entirely of the type 1 receptor form.