Temporal variation in the recovery from impairment in adriamycin-induced wound healing in rats

BACKGROUND: An adriamycin-induced impairment of wound healing has been demonstrated experimentally in rats. The purpose of this study is to investigate a possible temporal variation in recovery from the impairment of wound healing caused by adriamycin administration. METHODS: The subjects were 120 female Spraque-Dawley rats. They were divided into eight groups, undergoing adriamycin administration (8 mg/kg, i.v.) at 9 a.m. or 9 p.m. on day 0 and laparotomy on day 0, 7, 14 or 21. Blast pressures were recorded after the incision line had been opened, and tissue samples were kept at -30°C for later measurement of hydroxyproline levels. RESULTS: Adriamycin treatment in rats at 9 p.m. resulted in significantly lower blast pressure levels than treatment at 9 a.m. between days 7 and 21, indicating a lag effect of healing time in wounded tissues. However the decreased hydroxyproline levels were not changed at these days and sessions. CONCLUSION: It is concluded that adriamycin-induced impairment of wound healing in adult female rats exhibits nycthemeral variation.