Changes in Ribs of Guinea Pigs Following Administration of Cattle Anterior Pituitary Extract. ( Acromegalic Rosary )

Abstract

Summary

Administration of acid extract of cattle anterior pituitary, when continued over long periods of time, leads to the following changes at the chondro-osseous junction of the ribs of the growing guinea pig: (1) The preexisting resting and columnar cartilage cells undergo hyperplastic and hypertrophie changes which are associated with certain retrogressive processes in the cells. (2) In the cells of the perichondrium and periosteum a pronounced hyperplasia takes place followed by an accelerated conversion of these cells into cartilaginous tissue with subsequent calcification. (3) The bone marrow becomes transformed into fibrous connective tissue in which cartilaginous islands develop in places adjoining the hyperplastic cartilage. Through the cooperation of both these growth processes an abundance of cartilage may develop.

We find various transitions between ordinary hypertrophy and hyperplasia of the preexisting cartilage cells to the formation of a rosary-like newgrowth. In advanced cases, at a time when usually the growth of the skeleton is terminated, the formation of tissue may become so very extensive that it leads to the production of a parosteal “rosary”. These changes are very similar to those described by Erdheim 3 in cases of human acromegaly. They also correspond to the alterations observed by us in the cartilage of the epiphyseal line and the joint following injections of the extract over shorter periods of time. These changes may be even more marked in thyroidectomized than in non-thyroidectomized animals, which provides further proof for the conclusion that, in guinea pigs, cattle anterior pituitary extract acts on the growth of bone and cartilage without the mediation of the thyroid gland.