The effects of brain natriuretic peptide on scar formation in incisional rat wounds.

Background: Brain natriuretic peptide (BNP) is a peptide that reduces scar formation in the heart by blocking transforming growth factor-beta (TGF-beta). Although TGF-beta is known to play a role in scar formation in the myocardium, little is known about the effects of BNP on cutaneous wound healing.

Objectives: The objective was to determine if the administration of BNP in healing cutaneous wounds reduces the amount of scarring.

Methods: This was a laboratory investigation using 40 wild-strain rats. Three full-thickness 1-cm incisional wounds were created on each animal and randomized to intradermal BNP, saline, or no treatment. Wounds were excised at 3, 7, 14, 31, and 60 days and examined histologically for scar surface area and collagen architecture. Those wounds excised at 30 days were subjected to a measure of tensile strength and those excised at 60 days were evaluated prior to excision for cosmesis using a scar evaluation scale. The proportion of wounds healing without visually apparent scar was the main outcome. Groups were compared with Fisher's exact and Kruskal-Wallis tests.

Results: Wounds treated with BNP were more likely to heal without an apparent scar when compared to those treated with saline or control (37.5% vs. 0%, p = 0.03). There were no between-group differences in the surface area of the scars or the collagen architecture. Incisional tensile strength was also similar across treatments.

Conclusions: Treatment of rat incisions with BNP reduced the number of visually apparent scars but did not affect the histologic appearance of the scars or the incisional tensile strength.