Microfilaments and intermediate filaments (Ifs) represent an important components of the cytoskeleton. In mammals including rats, peritubular myoid cells (PMCs) contain alpha smooth muscle actin (ct-SMA) micro-filaments, while sertoli cells contain intermediate filaments vimentin. Previous studies mentioned some aspects about the distribution of these filaments in these cells, however little was mentioned about the changes in their distribution during postnatal (p.n) development.
In the present study, immunohisto-chemical methods were used to detect the changes in distribution of a-SMA in PMCs and vimentin in sertoli cells during postnatal development of rat testis (one day,7 days,14 days,28 days.42 days and 56 days) a- SMA immune reaction was seen early from the 1 st day of p.n age in few PMCs. On p.n day 7. there was increase in PMCs exhibiting +ve a-SMA immune reaction. This reaction was well established around the whole circumference of the seminiferous tubules on p.n day 14 and the adult distribution pattern was seen on p.n day 28. Intermediate filaments (Ifs) vimentin were mainly observed at the basal nuclear region of few sertoli cells on p.n day 7 and the first appearance in supranuclear or apical region was on p.n day 14.