Occurence of fibronectin was detected in paraffin sections of burn skin samples, excised from surviving patients, as well as skin samples removed from the death persons, who succumbed burn wounds. The other groups of samples, used for comparison with the previous one, consisted of the intact skin excisions and skin samples post-mortem exposed to thermic changes. Indirect immu- noperoxidase reaction was the immunohistochemical method used in all examinations. In post-mortem burn skin samples there was a loss of fibronectin activity in the epidermo-dermal junction area as well as in the papillary dermis. In burn skin samples, excised from patients who only survived for very short time their (serious skin) burns, no evidence of any fibronectin activity was seen. Also in two other cases, when patients - due to their severe burns - survived for several hours only, there were no conspicuous differences in the intensity of fibronectin activity seen in comparison with features found in the intact skin samples. Fibronectin activity was, however, increased in all other burn skin samples, where the survival time of patients was from 30 minutes to 5 weeks and there were following differences in its intensity and also in its pattern of distribution. In the 1st-degree and in a superficial 2nd-degree skin burn wounds, fibronectin was also present in the epidermis. In the papillary dermis, fibronectin was distributed rather diffusely or in a spot-like pattern while in the reticular dermis, there was a tendency to form net-like structures among collagen fibers. In deeper 2nd-degree and in the 3rd-degree burn wounds, fibronectin was deposited in vicinity of blood vessels and skin appendages in a fibrillar pattern. In 6 out of 11 samples, where the survival time ranged from 7 to 21 days, fibroblasts were arranged among fine collagen fibers and some of these cells exhibited positive fibronectin activity on their surface. Numerous fibroblasts with finely scattered fibronectin spots and also a decrease of fibronectin activity were observed in more mature granulation tissue, present in burn skin samples where survival time of patients was five weeks.

        Key words: fibronectin - burns - immunohistochemistry