A novel and simple technique for ectopic transplantation of the pituitary gland

Sites for ectopic transplantation of the pituitary include the kidney capsule of mammals, the anterior eye chamber, the so-called hypophysiotropic area of the brain, the third cerebral ventricle, and the tail of the amphibian tadpole. Transplantation of pituitary in the kidney capsule of mammals is a simple technical procedure but most nonmammalian species do not offer such a convenient site. Transplantation of pituitaries at other ectopic sites involves technical sophistication and cannot be undertaken by all investigators, and retrieving the transplant is often difficult. A new technique is described to overcome these difficulties. Silastic tube pieces (7-10 mm) were ligated at both ends and cut longitudinally, and pituitaries taken from sister animals (homologous donors) were inserted through the incision. The Silastic tubes were then implanted either in the abdominal cavity or in the liver of rat, Japanese quail, and toad. They were retrieved after 7 or 14 days (in the case of rat and Japanese quail) or after 10 or 20 days (in the case of toad), and the pituitary was sectioned and stained immunocytochemically using rat and human prolactin (PRL) antisera. Taking the preponderance of PRL cells in the pars distalis as a parameter for determining the viability and functional status of the transplants (because ectopically transplanted pituitaries secrete abundant PRL), it was found that 13 of 16 pituitary homografts had been well established and there was no visible host-graft incompatibility. The technique reported is novel and simple, and it ensures quick delivery of the grafts and their easy retrieval without any loss whatsoever. It is expected that the technique would be very useful and would find wider application because it can also be employed for transplanting other organs/tissues into a wide range of animals, including invertebrates.