I.S. Raginov Dr.Sc. (Med.), Head of Department of Pathology Republican Clinical Hospital, Associate Professor, Department of Histology, Kazan State Medical University, Kazan, Russia. E-mail: raginovi@mail.ru G.V. Vafina Post-graduate Student, Department of Histology, Kazan State Medical University, Kazan, Russia V.I. Egorov Ph.D. (Vet.), Head of Department of Veterinary Pharmacology, FCTRBD-VNIVI, Kazan, Russia M.V. Lekishvili Dr.Sc. (Med.), Head of Laboratory «Tissue Bank», N.N. Priorov Research Institute of Traumatology and Orthopaedics, Moscow, Russia. E-mail: leki@mail.ru

E-mail: leki@mail.ru In dorsal root ganglion by morphofunctional attributes, distinguish the large proprioceptive neurones with myelinic fibers and small pain neurones which have unmyelinic fibers. It has been shown, that P2Y-receptors participate in all key endocellular processes: a proliferation, migration, a differentiation and apoptosis. The large neurones expressing P2Y4-receptors, and small neurones P2Y1. Glial cells  Schwann-s cells and cells - sattelite expressing P2Y2 and P2Y12. The purpose of our research  to estimate change of regenerating myelinic and unmyelinic fibers number in a sciatic nerve of a rat under influence of not selective blocker of P2Y-receptors  Reactive Blue 2. In experiment 16 rats male have been used. At all animals unitary a nerve crush by means of microsurgical a clamp such as «mosquito» duration 30 with on standard procedure. Next day after operation of 8 animals i/p introduced so-lution Reactive blue 2 (30 mg/kg). The staying 8 animals in similar conditions introduced a normal saline solution. For 15 day after operation secreted a distal fragment of a nerve and fixed, dehydrated and concluded in epon-araldit. Transversal semithinc sections of a nerve imbued Metyle Blue and used for inventory of amount of myelinic fibers. Inventories carried out on the light microscope (Jenaval) at augmentation х600 with the built - in ocular grid. Number of unmyelinic fibers counted up with use of a electron microscope (Hitachi). By 15 day after of crush nerve under influence Reactive Blue 2 does not descend change of number myelinic, but the number unmyelinic fibers decreases by 73,8%. Results of our work specify big value P2Y of receptors in posttraumatic neogenesis of a nerve.