Long-term
hormone replacement therapy due to
panhypopituitarism can lead to serious complications and thus, pituitary
transplantation is considered a more desirable. We investigated functional restoration after allotransplatation of the pituitary gland. We transplanted extracted pituitary gland into the omentum of an hypophysectomized rat. Two experiments were performed: (1) to confirm the
hypophysectomy was successful and (2) to assess functional restoration after pituitary
transplantation. Pituitary
hormone level and weight change were consecutively assessed. Electron microscopic (EM) examinations were performed to identify morphological changes at 3 days after
transplantation. We confirmed that pituitary gland was properly extracted from 6 rats after sacrifice. The findings showed (1) a
weight loss of more than 3% or (2) a weight change of less than 2% along with a decreased
growth hormone (GH) level by more than 80% at 2 weeks post-
hypophysectomy. A further four rats underwent pituitary
transplantation after
hypophysectomy and were compared with the previously hypophysectomized rats. All showed rapid
weight gain during the two weeks after
transplantation. The
thyroid-stimulating hormone,
prolactin, and GH levels were restored at one week post-
transplantation and maintained for 10 weeks. Hypophyseal tissue architecture was maintained at 3 days after
transplantation, as indicated by EM. These data suggest that a transplanted pituitary gland can survive in the omentum with concomitant partial restoration of
anterior pituitary hormones.