An electron microscopic study of cells with steroid-secreting morphology in the paraaortic lymph node of the hamster.

Clustered cells with steroid-secreting morphology (SH), located within the paraaortic lymph node (PLN) capsules of normal and pregnant female golden hamsters, were examined by light and electron microscopy. Hydroxysteroid dehydrogenase (HD) activity of the SH cell cluster also was examined by histochemical techniques. The cluster was composed of mostly packed SH cells and surrounding mesenchymal cells. Individual SH cells possessed prominent smooth endoplasmic reticulum, well-developed Golgi complexes, some lipid droplets, and numerous mitochondria containing tubulovesicular cristae common to mammalian SH cells. Intermediate-type junctions were often observed between SH cells. The same SH cells were rarely detected in the subcapsular sinus and in the cortical parenchyma of the PLN. Early oophorectomy of the hamster resulted in cytoplasmic degeneration of the SH cell at day 5 after the operation. On the other hand, normal adult male hamsters possessed similar PLNs, but no SH cells were recognized in the nodes. The present histochemical preparation of normal female PLNs revealed moderate-to-strong HD activity, probably associated with SH cell clusters, in the limited regions of the capsules. Based on the present ultrastructural and histochemical findings, it is proposed that the SH cell cluster consists of steroid hormone producing cells.