Dispersed cell cultures of the rat pineal: growth and morphological differentiation.

A method is described for the preparation and growth of rat pineal monolayer cultures derived from both mature and immature animals. The cultures were observed to undergo profound but reversible morphological differentiations by addition of dibutyryl-cAMP, monobutyryl-cAMP, papaverine, prostaglandins, and adenosine, and by removal of serum. Sodium butyrate and theophylline had no effect. Time-lapse photography indicated that this reversible transformation took place via a contraction-relaxation mechanism. Both colcemid and cytochalasin B inhibited the transformation. These results demonstrate that this type of morphological transformation, previously demonstrated in tumour and embryonic cell cultures, can also occur in nonembryonic, non-neoplastic tissue, and may be related to a general dedifferentiative process occurring in monolayer cultures.