[The effect of nerve tissue growth factor on the structural-functional state of the sympathetic neurons after cutting their axons].

Abstract

Under study was the influence of the nerve growth factor on morpho-functional and cytometrical characteristics of sympathetic neurons after cutting their axons. The work was carried out in albino rats which were subjected to dissection of the external and internal carotid nerves of the cranial cervical ganglion. This operation resulted in death of about 50% of the neurons of the node in question, in 30 and 60% in reduction of the intensity of fluorescence of the neuron body catecholamines within 7 and 14 days. The cause of these changes might be the cessation of entrance of the nerve growth factor from target tissues by means of retrograde transport. After 6-10 exogenous administrations of the latter (10-20 mkg/g of the body weight) 14 days after operation the amount of neurons in the cranial cervical ganglion did not practically differ from that in the group of intact rats. Seven and fourteen days later specific luminescence of the neuron body catecholamines was 24-22% greater than the values found in the operated animals given the isotonic solution of sodium chloride. Parallel stimulation of the formation of a powerful network of collateral branches by injured axons was performed resulting in more considerable (3-fold) increase of the ganglion mass than in the operated animals (2-fold) not treated with a neuro-growth protein. The newly formed fibers had not only an intercellular but also subcapsular arrangement which spoke of higher reparative--regenerative potencies of the neuron.