Organ culture of foetal rat pancreas. Effects of parabiotic culture with foetal adrenal glands.

The differentiation and growth of the foetal rat pancreas (20 days postcoitum) was studied in parabiotic organ culture with foetal adrenal tissue. In such co-cultures, characteristic pancreatic morphology was preserved and further acinar cell differentiation was fostered. Acinar cells contiunued to represent about 65% of the total explant volume following short-term incubation. The selective islet cell proliferation, previously observed in control pancreatic explants cultured alone, did not occur when adrenals were co-cultured. In addition, the amylase content of the incubation media and of the explanted pancreatic tissue remained high with adrenal co-culture, while the insulin content of the media and of the explanted tissue was markedly suppressed when compared to control pancreatic explants cultured alone. The effects of the adrenal in maintaining the differentiated acinar component of the pancreas and suppressing media insulin concentration diminished over extended incubation. The addition of adrenals to culture of foetal pancreatic explants after 6 days of control culture (at a time when differentiated acinar cells were not identifiable in the explant) did not result in redifferentiation of the acinar component, but did markedly depress media insulin content. Removal of adrenals after 4 days of co-culture resulted in an immediate rise in media insulin concentration and a rapid decline in pancreatic acinar mass. An adrenal-exocrine pancreatic axis is proposed and it is suggested that foetal adrenal secretions may play an important role in the development of the exocrine pancreas in vivo as well as in vitro.