Histological study of the operative zone in dogs with parotid gland grafts in the sella turcica.

No remnants of adenohypophyseal tissue were found in 83% of the 70 dogs studied; in 17% of the animals remnants amounting to from 1 to 3% of normal hypophyseal tissue were found. These traces showed significant histological and cytological changes, and were most frequently found located on the floor of the sella turcica at some distance from their usual site. It is doubtful whether these residua have any functional significance, since the hypophysectomized dogs with such remnants had a survival time that corresponded to that of dogs with total hypophysectomy (6 months). The microscopic structure of the fragment of transplanted parotid (salivary gland) presents rich vascularization, changes in cellular distribution and a loss of the excretory duct. A better histological aspect was observed in the transplanted cells of the dogs with longer survival time. An important correlation exists between functional behavior of the operated animals and the histological state of the transplanted parotid tissue.