Junctional specialization in estrogen-induced renal adenocarcinomas of the golden hamster

Estrogen-dependent renal adenocarcinoma and normal proximal tubules of the hamster kidney exhibit junctional differences. Although both cell types possess gap junctions, the neoplastic cells have in addition a cytoplasmic configuration of gap-junctional membrane (annular nexuses) not found in the kidneys of untreated or estrogenized hamsters or in the nontumorous kidney adjacent to the adenocarcinoma. The presence of these unique structures in the renal tumor and its abdominal metastases was demonstrated by electron microscopy with the use of lanthanum impregnation. A possible correlation between these structures and the estrogen sensitivity of the kidney neoplasm is made.