Heterotransplantation of human prostatic tissue.

Pieces of human prostatic tissue (approximately 1 mm3) were encapsulated in XM-50 Amicon hollow fibers and either implanted into the testis of an adult male rat or placed in culture. The protein synthetic capacity of such tissue pieces removed 1-42 days later was monitored by TCA precipitation, SDS-PAGE, and autoradiography. The results showed that tissue pieces retained their functional protein synthetic elements after this procedure. A newly developed solid-phase enzyme immunoassay for human prostatic antigen (PA), described in this report, was used to monitor PA levels in the serum of the recipient host or culture media. In some instances PA was detected 1-2 weeks postimplantation, a result that implies maintenance of functional secretory elements in vivo. Finally, morphology of tissue pieces 1-2 weeks postimplantation sometimes showed the presence of ductal epithelia and stromal elements in distribution patterns typical of those seen in fresh biopsy samples. We conclude that the function and structure of prostatic tissue implanted intrastesticularly compares favorably with that maintained in conventional explant culture. As such, the hollow fiber method offers promise for a new way of monitoring hormonal and/or chemotherapy testing of human prostatic tissue.

Pituitary cell transplants to the cerebral ventricle suppress the pituitary of the recipient host.

Implantation of 1 x 10(6) acutely dispersed rat pituitary cells into the lateral ventricles of sexually immature and mature female rats of both the Sprague-Dawley and Fisher strains significantly suppressed the weight and protein content of the in situ pituitary 12 days postimplantation. Body weight gains in the young animals were also significantly lower. Changes in the in situ pituitary of the cell implanted groups were demonstrated by repeatable reductions (approximately 50%) in total pituitary GH and PRL content. Total pituitary TSH, FSH and LH were usually unaffected. Although the mechanism of cell-mediated suppression of the host pituitary is unknown, the approach should be of use in future studies of feedback regulation on pituitary gland function.

Pituitary hollow fiber units in vivo and in vitro.

A new technique is described for the study of mammalian pituitary cells in vivo and in vitro. The method involves encapsulation of freshly trypsinized rat, sheep or human pituitary cells in XM-50 Amicon hollow fibers followed by their intracranial implantation into hypophysectomized rats. These pituitary fiber units promoted recipient growth for 3 weeks before weight gains plateaued. Body composition analyses showed that significant quantities of protein, fat and ash accounted for the weight gain. Morphological study of the capsule contents 7-39 days postimplantation revealed the presence of intact somatotrophs and corticotrophs. The hollow fibers may provide an immunologically privileged site by virtue of the fact that the 50,000 dalton pores making up the lumen surface permit pituitary hormones to diffuse from the capsule, but theoretically do not permit immunoglobulin molecules to penetrate the capsule. Growth of hypox rats receiving capsules containing allogeneic rat pituitary cells, sheep cells or pieces of human postmortem pituitary support this concept. Furthermore, rats implanted with human PRL adenoma cells had detectable quantities of circulating hPRL 100 days postimplantation. It is suggested that the pituitary hollow fiber units function when they come in contact with a ventricular surface of a hypox animal. With these units, it will be possible to study function of the same group of pituitary cells in vitro and in vivo.