The main cause in formation of the polyorgan insufficiency syndrome, which is a definitive one in severe trauma, is a syndrome of endogenous intoxication. While simulation of the mechanical trauma, of the burn on the polytrauma background there were noted essential enhancement of the middle molecular mass peptides (MMMP) content and the transaminases activity with maximum value at the 7th day of follow-up. The degree of the investigated indices enhancement on the burn background have had overweighted such after the mechanical trauma. There was established, that application of xenodermoplasty for temporary substitution of the affected skin impacts positively the organism general state, promotes the MMMP concentration reduction and the transaminases activity normalization.