O.R. Shangina - Dr.Sc. (Biol.), Leading Research Scientist, FSBI «Russian Eye and Plastic Surgery Centre» of the Russian Federation Ministry of Health, Ufa, Russia. E-mail: alloolga@mail.ru L.A. Musina - Dr.Sc. (Biol.), Leading Research Scientist, FSBI «Russian Eye and Plastic Surgery Centre» of the Russian Federation Ministry of Health, Ufa, Russia. E-mail: morphoplant@mail.ru L.A. Bulgakova - Ph.D. (Biol.)., Research Scientist, FSBI «Russian Eye and Plastic Surgery Centre» of the Russian Federation Ministry of Health, Ufa, Russia

The relevance of the study of lyophilized and preserved tendinous allograft regeneration peculiarities is determined by the absence of these data. The aim of the investigation was a comparison analysis of regenerative properties of preserved and lyophilized allo-grafts made from Achilles tendon (dense regular connective tissue with an oriented type of fibrous framework). Achilles tendon orthotopic transplantation was selected as an experimental model. Allograft transplantation in the control (preserved in ethanol) and experimental (lyophilized) groups was performed on 40 sexually mature Wistar rats. The results of the investigation allowed to evaluate differences in the resorption - replacement process following the implantation of preserved and lyophilzed Achilles tendon. In the first series of the experiments Achilles tendon al-lografts had retained fibroarchitectonics. In the second series lyophilized allografts had pronounced changes of the fibrous framework. In the control group of the animals the allograft resorption and replacement process ended with the formation of the dense connective tissue regenerate with the architectonics similar to the tendon. The orthotopic allotransplantation of lyophilized Achilles tendons led to the quick and total replacement. When this takes place the role of allograft fibrous framework morphogenesis factor is excluded. The formed connective tissue regenerate re-sembled fibrous tissue with a disordered architectonics of collagen fibres. Thus, change degree of allograft fibroarchitectonics and plastic properties depending upon the treatment determined the resorption speed, character of replacement and structure of the formed regenerate. A substantial restriction in the use of lyophilized allografts is their inefficiency when they are used in reinforcement operations with tissue physico-mechanical properties playing the main part. Lyophilized connective tissue allografts may be used in filling in extensive volume defects of different tissues, in neurosurgical practice, as closing membranes, to restore tissues with a drainage function, as allogenic carriers for various physical preparations.