The Effect of Sciatic Nerve Transection on the Somatostatin and Substance P Cells in Dorsal Root Ganglia of Rats

ABSTRACT

The authors investigated the morphometric analysis of substance P(SP)- and somatostatin(SOM)- containing nerve cells in dorsal root ganglia. For this purpose, immunohistochemical method was used to determine the number, size and the morphological characteristics of SP- and SOM-reactive cells in L5 dorsal root ganglia of rats. In addition, changes in type A, type B, SP- and SOM-containing nerve cells in ganglia after sciatic nerve transection were also determined. The results were as follows 1) SP- and SPOM-reactive nerve cells belong to the population of type B cell, but N/C ratios of immunoreactive cells were higher than others ; 2) in normal group, SP- and SOM-reactive nerve cells were 12.5 and 3.2% of total nerve cells in ganglia, respectively ; 3) the case of coexistence of SP and SOM in one cell was not found ; 4) and there was a marked reduction in the number of SP- and SOM-reactive cells at 2 weeks after nerve injuries. And SP-reactive nerve cells were increased in number at 6 weeks after operation, but SOM-reactive cells were not. According to these results, SP- and SOM-reactive nerve cells belong to type B cells, but do not coexist in one cell. These nerve cells were decreased in number after nerve transection. SP-reactive nerve cells were recovered at 6 weeks after operation but recovery of SOM-reactive cell was not found.