The effects of hypophysectomy on the digestive glands of the mouse.

The objective was to observe the influence of hypophysectomy on the secretory cells of digestive glands in the mouse and to compare these findings with those reported for other mammalian species. Hypophysectomy of the mouse induced involutional changes in glandular cells concerned with secretion of proteins and mucins, and in those involved in ion transport or release. Gastric chief cells, pancreatic acinar cells, and serous cells of submandibular tubules were markedly involuted; acinar cells of the parotid gland were changed less significantly. Gastric mucous neck cells and mucous acinar cells of the submandibular and sublingual glands contained less secretory material. A colloidal iron-positive variety of mucous neck cell became dominant. These changes were less profound than those which occurred in most types of zymogenic cells. Parietal cells became atrophic and contained a greatly contracted intracellular canalicular system. Salivary ducts of the parotid and sublingual glands showed partial involution. It was concluded that, as in the rat and man, proteinsecreting cells of the digestive tract of the mouse depend on the support of pituitary hormones. Those cells which secrete mucopolysaccharides or are involved in ion transport also require pituitary hormones for complete maintenance of their structure and function. Schooley, Riddle and Bates ('41) first demonstrated that the pituitary gland influences the digestive system, by observing a loss in weight of the gastrointestinal tract in the pigeon after hypophysectomy. More recently, others have shown that the hypophysis exerts significant control over the structure and function of digestive glands in the rat. Thus, all zymogenic cells which have been studied are dependent on the support of pituitary and other hormones for maintenance of normal structure and full secretory activity. These include the gastric chief cell (Baker and Abrams, '54), acinar cells of the pancreas (Haist, '55) and parotid gland (Baker and Abrams, '55), zymogenic cells of the submandibular serous ducts (Lacassagne and Chamorro, '40) and cells of Paneth in the intestine (Baker et al., '58). In addition, mild structural involution (Baker and Abrams, '54; Baker and Clark, '61) and functional depression (Crafts and Walker, '47) take place in the gastric parietal cells after pituitary ablation. In contrast to the rather detailed information available concerning the action of hormones on the digestive glands of the rat, relatively little is known about their effects in other mammals. Investigations AM. J. ANAT., 121: 571-600. carried out on the stomach indicate that regressive changes occur during pituitary deficiency in the cat (Cutting et al., '37; Haeger et al., '53) and man (Laumonier et al., '63; Dotevall and Westling, '63). In this report, the influence of hypophysectomy on the histology and histochemistry of the gastric mucosa, pancreas and parotid, submandibular and sublingual glands of the mouse will be described. Such information will help to indicate the extent to which digestive glands of mammals in general are dependent on hormonal stimulation. MATERIALS AND METHODS The experiments were carried out on young adult male ICR Swiss mice. Hypophysectomy was performed by the transauricular method of Falconi and Rossi ('64). Completeness of hypophysectomy was verified by histological observation of serial sections of the pituitary region. Incompletely hypophysectomized mice were discarded. A nonhypophysectomized mouse 1 Supported in part by research grant AM 00131-14 from the United States Public Health Service. ZFrom a dissertation submitted in partia! fuIfillment of the requirements for the Doctor of Philosophy degree.