Interrelationship between annulate lamellae and the cytoplasmic microtubule complex in tumor cells in vivo and in vitro.

Annulate lamellae were observed in untreated in vivo ascites tumor cells with a diminished cytoplasmic microtubule complex. The ascites tumor cells in vitro responded to prolonged colchicine treatment with the formation of annulate lamellae. Simultaneous treatment with dibutyryl cycle adenosine monophosphate and colchicine seemed to enhance the formation of annulate lamellae. Single pore complexes were found in the granular endoplasmic reticulum in untreated tumor cell in vitro, and a close association of microtubules with the nuclear envelope was observed. Our results suggest the existence of an interrelationship between the cytoplasmic microtubule complex and certain other cell structures, i.e. the nuclear envelope, annulate lamellae, and single pore complexes.