|
|
||||||||
The release of oxytocin in response to an osmotic stimulus and immobilization stress was compared in lactating rats 8–12 days after delivery and in non-lactating rats. Intravenous injection of hypertonic saline or immobilization stress induced an increase in blood oxytocin levels in both lactating and non-lactating rats, but the increment in the former was significantly lower than that in the latter. The lower responsiveness of oxytocin release to stress in lactating rats was not altered by ovariectomy 2 days after parturition. Oxytocin release induced by electrical stimulation of the anteroventral third ventricle (an osmoreceptive area), paraventricular nucleus and neurohypophysis was significantly lower, to a similar extent, in lactating rats compared with non-lactating rats. These findings indicate that the structural reorganization reported in the hypothalamo-neurohypophysial system may not function to facilitate release of oxytocin in response to stress and osmotic stimulus in lactating rats. The reduced responsiveness of the release of oxytocin is independent of the influence of ovarian hormones, and may be due to the low ability of the oxytocin neurone itself to release oxytocin, and/or due to the activated inhibitory influence on the oxytocin neurone in the lactating rat.
J. Endocr. (1988) 116, 225–230
This article has been cited by other articles:
![]() |
A. J. Tilbrook, A. I. Turner, M. D. Ibbott, and I. J. Clarke Activation of the Hypothalamo-Pituitary-Adrenal Axis by Isolation and Restraint Stress during Lactation in Ewes: Effect of the Presence of the Lamb and Suckling Endocrinology, July 1, 2006; 147(7): 3501 - 3509. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. D. Hill, J. C. Aldag, R. T. Chatterton, and M. Zinaman Psychological Distress and Milk Volume in Lactating Mothers West J Nurs Res, October 1, 2005; 27(6): 676 - 693. [Abstract] [PDF] |
||||
![]() |
M. Heinrichs, G. Meinlschmidt, I. Neumann, S. Wagner, C. Kirschbaum, U. Ehlert, and D. H. Hellhammer Effects of Suckling on Hypothalamic-Pituitary-Adrenal Axis Responses to Psychosocial Stress in Postpartum Lactating Women J. Clin. Endocrinol. Metab., October 1, 2001; 86(10): 4798 - 4804. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. P. H. Burbach, S. M. Luckman, D. Murphy, and H. Gainer Gene Regulation in the Magnocellular Hypothalamo-Neurohypophysial System Physiol Rev, July 1, 2001; 81(3): 1197 - 1267. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. E. Stern and W. E. Armstrong Reorganization of the Dendritic Trees of Oxytocin and Vasopressin Neurons of the Rat Supraoptic Nucleus during Lactation J. Neurosci., February 1, 1998; 18(3): 841 - 853. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. J. Windle, M. M. Brady, T. Kunanandam, A. P. C. da Costa, B. C. Wilson, M. Harbuz, S. L. Lightman, and C. D. Ingram Reduced Response of the Hypothalamo-Pituitary-Adrenal Axis to {alpha}1-Agonist Stimulation during Lactation Endocrinology, September 1, 1997; 138(9): 3741 - 3748. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. J. Windle, N. Shanks, S. L. Lightman, and C. D. Ingram Central Oxytocin Administration Reduces Stress-Induced Corticosterone Release and Anxiety Behavior in Rats Endocrinology, July 1, 1997; 138(7): 2829 - 2834. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. E. Stern and W. E. Armstrong Changes in the Electrical Properties of Supraoptic Nucleus Oxytocin and Vasopressin Neurons during Lactation J. Neurosci., August 15, 1996; 16(16): 4861 - 4871. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. S. Fenelon and A. E. Herbison Plasticity in GABAA Receptor Subunit mRNA Expression by Hypothalamic Magnocellular Neurons in the Adult Rat J. Neurosci., August 15, 1996; 16(16): 4872 - 4880. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | CONTACT US | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |