Overlapping effect of follicle stimulating hormone (FSH) and thyrotropin (TSH) on the ultrastructure of immature chicken testes.

In newly hatched chicken testes the gonadotropin receptors due to their immaturity are not specific but still structurally versatile and so they can bind both FSH and TSH which have a chemically related structure. The functional overlapping effect of FSH and TSH on the ultrastructure of Sertoli and Leydig cells of immature chicken testes was investigated. The activity of Sertoli cells was increased by FSH treatment and this increase correlated well with the amount of SER and RER in cells and with their increased surface activity. The vacuolization and degeneration observed at the apical part of the cells may refer to the formation of testicular tubules. After TSH treatment cell activity increased and in addition a considerable increase in RER and lipid droplets was observed. Fenestrated cisternae were often found in the Sertoli cells of the treated animals. In the Leydig cells, both hormones increased lysosomal activity and the number of lipid droplets. After FSH treatment the amount of SER increased while after TSH treatment the Golgi activity.