Functional and Morphological Changes in the Hypothalamus-Pituitary Posterior Lobe System after Hypophysectomy in the Dog

Journal of Veterinary Medical Science

Susumu TAKEKOSHI¹  Robert Y. OSAMURA¹  Yasushi HARA²  Hiroyuki MASUDA²  Yoshinori NEZU²  Masahiro TAGAWA²  Naoko SANNO³  Takahiro TAODA²  Akira TERAMOTO³ 

[1] Department of Pathology, Tokai University School of Medicine;Division of Veterinary Surgery, School of Veterinary Medicine, Nippon Veterinary and Animal Science University;Department of Neurosurgery, Nippon Medical School

关键词: arginine vasopressin;    canine;    hypophysectomy;    hypothalamus;    pituitary;   

DOI  :  10.1292/jvms.68.1

学科分类：兽医学

来源: Japanese Society of Veterinary Science

【 摘 要 】

References(30)Cited-By(1)Acute diabetes insipidus-like symptoms have been reported as a complication after hypophysectomy in dogs. These symptoms are believed to be the consequence of deficiency of arginine vasopressin (AVP) secretion. The symptoms spontaneously resolve within 2 weeks, but the mechanism is unclear. In the present study, AVP secretion related to increases in Na+ concentration and serum osmotic pressure was measured, and immunohistochemical analysis in the paraventricular and supraoptic nuclei was perfomed after hypophysectomy in normal dog. In the hypertonic saline test, the plasma AVP concentration slightly increased in hypophysectomized dogs, although the increase was markedly smaller than that in normal dogs. An immunohistochemical study of the hypothalamus nucleus revealed that, AVP-positive cells tended to decrease after hypophysectomy. It suggests that excision of the posterior lobe by surgery injured the axon of magnocellular neuron in the hypothalamus. A decrease in the function and the number of AVP-producing and -secreting magnocellular neurons after hypophysectomy, suggests that the clinical improvement of postoperative diabetes insipidus-like symptoms may not be related to the recovery of AVP secretion.

【 授权许可】

Unknown