Abstract
This paper is a report of studies made upon the morphological response of the anterior lobe of the hypophysis following bilateral thyroidectomy in the salamander, Triturus torosus. The work was undertaken as a prelude to physiological studies upon amphibia designed to throw light upon the possibility of a reciprocal action between the thyroid and hypophysis. It seemed necessary to determine first whether or not the anterior lobe of a typical amphibian shows morphological changes after thyroidectomy such as have been reported by numerous investigators in the mammalia. (See Severinghaus1 for bibliography.)
The technic of thyroidectomy was essentially that recommended by Taylor. 2 Darkening of the integument 2 , 3 occurred usually some 15 to 25 days after operation. Animals were killed by decapitation after periods ranging from 5 to 114 days.
All glands were fixed in Heidenhain's “Susa” (Sublimate-Trichloracetic Formalin) and imbedded by the dioxan method. Sections were cut at 5μ and stained in hematoxylin, acid fuchsin, and anilin blue. In several cases sections of the hypophyses from control and thyroidectomized animals were mounted on the same slide to ensure uniform treatment.
Glands from 8 controls and 33 operated animals were studied. It appears that the most conspicuous change in the anterior lobe of Triturus torosus following thyroidectomy is the development of vacuoles in the cytoplasm of certain basophilic cells. The exact classification of these cells has not yet been worked out but it is supposed that they are degranulated basophiles.
The vacuoles apparently first make their appearance in small clusters in one or 2 localized areas of the cytoplasm. They may be in close association with the nucleus or considerably removed from it, all on one side of the nucleus or scattered around it.
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