[Postoperative debasement of the host-defense system and wound healing in elderly patients, and nutritional support as a therapeutic implication].

Plasma opsonic activity and several kinds of plasma protein levels in each pre- and post-operative days were compared between older 25 cases (70 years or older) and 31 younger cases (59 years or younger) which both underwent elective abdominal surgery. The activity to opsonize E. coli 075 as a host-defense capacity was reduced on postoperative days 1,3 and returned gradually in either young or elderly. But opsonic activity levels in elderly patients in each postoperative days were significantly lower than in younger group. Plasma albumin level and rapid turnover protein levels in elderly patients tended to be lower than those in younger group through the postoperative period but statistically not significant. Plasma levels of C3 and fibronectin overshot the each preoperative value on days 5-7, after sharp reduction on day 1 in younger patients, but those in elderly didn't. Opsonic activity levels were closely correlated with plasma protein levels. Based on these clinical results, the experiments were designed to evaluate the effect of nutritional support in the early postoperative period on opsonic activity and protein synthesis in aged rats. These studies elucidated that early nutritional support brought beneficial effects on opsonic activity and plasma protein levels on postoperative days 7, but not on days 3 in aged rats. This may be because in aged animals, protein synthetic function has not fully recovered in the early postoperative period.