Adrenocortical function in hypophysectomized dogs with parotid gland transplants in direct contact with the basal hypothalamus.

Adrenocortical activity was studied in three groups of dogs: control-normal, hypophysectomized (hypox), and dogs with a piece of parotid gland grafted into the sella turcica immediately after removal of the whole hypophysis (hypox + graft). Cortisol plasma level (Fk) was estimated by the competitive protein binding method. The mean base-line Fk for 21 normal dogs was 0.8 +/- 0.1 microgram/dl; for 12 hypox dogs 0.03 +/- 0.01 microgram/dl, and for hypox + graft dogs 0.5 +/- 0.2 microgram/dl. After mild or severe stresses the normal and hypox + graft dogs showed an increment in Fk; hypox dogs showed no change. Adrenal glands of hypox dogs revealed striking diminution in fasciculata and reticularis layers, whereas hypox + graft dogs approached normal. Light microscopy studies of the parotid gland graft showed signs of cellular differentiation. Groups of proliferating cells forming follicular structures were present mainly in the part of the parotid tissue closely associated to third ventricle presenting different staining affinities.