PROLIFERATION OF MAST CELLS IN PERIPHERAL NERVES DURING WALLERIAN DEGENERATION - A RADIOAUTOGRAPHIC STUDY

A study was made on mast cell proliferation in control and sectioned rat sciatic nerve using radioautography with3H-thymidine. The main findings were as follows: 1. In control nerves only a small fraction of the mast cell nuclei was labelled with3H-thymidine 45 minutes and 24 hours after the injection. 2. In the distal part of sectioned nerves from the same rats there was about a tenfold increase in number of labelled endoneurial mast cells on the fourth up to the fifteenth day after the operation. There was also an increased number of labelled mast cells in the perineurium and epineurium. The results indicate that mast cells in nerves can synthetisize DNA and proliferate by division and that the numerical increase previously observed in the endoneurial mast cell in sectioned nerves is preceeded by a significant proliferation of cells as soon as on the third day after the section. © 1969 Springer-Verlag.