ALTERATIONS OF ANGIOTENSIN-II RECEPTOR LEVELS IN SUTURED WOUNDS IN RAT SKIN

Angiotensin II receptor levels have been shown to vary with postoperat ive time in tissue harvested from full-thickness dermal excisional wou nds on adult rats. This study examined the expression of AII receptors in a sutured wound model. Two full-thickness incisional wounds were m ade in the dorsal skin of adult Sprague-Dawley rats and sutured immedi ately under general anesthesia. The wound tissues were harvested at 0, 0.5, 1, 2, 4, 24 h and on days 2, 3, 4, 5, 7, and 10 after the woundi ng. The levels of I-125-Sar(1).Ile(8)-AII bound to membrane preparatio ns of the wound tissues decreased at early time points (from 0.5 to 4 h) increased from day 1 to day 7, and returned to nonsurgical levels b y day 10. Competitive binding studies showed that the receptors were p redominantly of the AT1 receptor subtype. These results suggest that a n immediate and transient reduction in AII receptor expression occurre d after wounding, followed by an increase in the number of AII recepto rs that was maintained for 5 to 7 days postoperatively. Because these data are consistent with those observed after excisional wounding, tem poral changes in AII receptor expression may be integral to the proces s of wound healing.