Hollow fiber-encapsulated pituitary cells for the study of adenohypophyseal regulation of growth in poultry: 1. Preparation and use.

A technique for transplantation of viable, functionally active pituitary cells was adapted for use in poultry. Enzymatically dispersed adenohypophyseal cells were prepared from broiler strain donor chicks and loaded into hollow fiber capsules; ultrafiltration membranes consisting of an open-celled, spongy outer layer of polymer material with an internal lumen which is surrounded by a thin skin of tightly controlled pore size. Cell-filled capsules were surgically implanted intracranially into pituitary-intact, recipient birds for extended time periods. Immunoreactive growth hormone (I-GH)-containing cells persisted in hollow fiber capsules for up to 30 days of implantation. Final capsule I-GH reflected starting cell densities. Capsules implanted intracranially became highly vascularized, with capillary endings imbedded in the spongy, open-celled outer surface of the capsule. This provides a means for hormones secreted by cells contained within the capsule to reach the peripheral circulation. Mean plasma I-GH concentration of birds implanted at 10 weeks of age with capsules containing donor cells from 2 to 3-week-old chicks was significantly higher than sham-implanted controls by 2 weeks postimplantation. Thus, hollow fiber-encapsulated pituitary cells remain viable for extended time periods when implanted intracranially in pituitary-intact chickens. These capsules provide a means by which naturally secreted pituitary hormones may be administered in vivo and provide a viable model system for studies of adenohypophyseal hormone action.