HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 72/2/470    most recent biolreprod.104.035006v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Fink, J. W. Articles by Nicholson, H. D. Search for Related Content PubMed PubMed Citation Articles by Fink, J. W. Articles by Nicholson, H. D. Agricola Articles by Fink, J. W. Articles by Nicholson, H. D.

Seasonal Changes in Mesotocin and Localization of Its Receptor in the Prostate of the Brushtail Possum (Trichosurus vulpecula)

Department of Anatomy and Structural Biology,² Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand AgResearch Invermay,³ Mosgiel, New Zealand Department of Zoology,⁴ University of Melbourne, Parkville, Victoria 3010, Australia

The prostate gland in the brushtail possum grows and regresses seasonally. It has similarities to the human prostate and may therefore provide a unique model for investigating prostatic hyperplasia. Oxytocin has been implicated in the regulation of prostate growth in eutherian mammals, and the initial aim of this study was to identify and localize the marsupial equivalent, mesotocin, and its receptor in the prostate of the brushtail possum. Seasonal changes in prostatic mesotocin concentrations and receptor localization were then assessed and related to prostate growth. Mesotocin and mesotocin receptor gene transcripts with high sequence homology to eutherian oxytocin/oxytocin receptors were demonstrated, and mesotocin, neurophysin, and the receptor were all localized predominantly in the epithelial cells of the glandular acini. Western blot analysis confirmed the presence of a single immunoreactive receptor protein of 60 M_r^–3. Prostatic mesotocin concentrations were highest immediately before the increases in prostate weight associated with the autumn and spring breeding periods. At this time, mesotocin receptors were also present in the prostatic capsule in addition to those present in the glandular tissue. Mesotocin concentrations proceeded to decrease in association with the regression of prostate size toward the end of the breeding periods. No significant differences were present in serum testosterone or dihydrotestosterone throughout the year. The identification of mesotocin and its receptor in the possum prostate and the demonstration of seasonal changes in local mesotocin concentrations preceding changes in prostate size suggests that mesotocin may play a physiological role in regulating prostate growth and regression.

¹ Correspondence: Helen Nicholson, Department of Anatomy and Structural Biology, Otago School of Medical Sciences, University of Otago, P.O. Box 913, Dunedin, New Zealand. FAX: 64 3 479 7254; helen.nicholson{at}stonebow.otago.ac.nz

This article has been cited by other articles:

				M L Gould, P R Hurst, and H D Nicholson The effects of oestrogen receptors {alpha} and {beta} on testicular cell number and steroidogenesis in mice Reproduction, August 1, 2007; 134(2): 271 - 279. [Abstract] [Full Text] [PDF]

				H. Thackare, H. D. Nicholson, and K. Whittington Oxytocin--its role in male reproduction and new potential therapeutic uses Hum. Reprod. Update, July 1, 2006; 12(4): 437 - 448. [Abstract] [Full Text] [PDF]