This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart 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 Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Sjöquist, M. Articles by Sved, A. F. Search for Related Content PubMed PubMed Citation Articles by Sjöquist, M. Articles by Sved, A. F.

Sodium Excretion and Renin Secretion after Continuous Versus Pulsatile Infusion of Oxytocin in Rats¹

Department of Physiology, Biomedical Center, Uppsala University (M.S., E.J.), Uppsala S-75123, Sweden; the Department of Physiology, University of Odense (O.S.), Odense DK-5000, Denmark; and the Department of Neuroscience, University of Pittsburgh (W.H., E.M.S., A.F.S.), Pittsburgh, Pennsylvania 15260 U.S.A.

Address all correspondence and requests for reprints to: Dr. Mats Sjöquist, Department of Physiology, Box 572, Biomedical Center, S-75123 Uppsala, Sweden. E-mail: mats.sjoquist{at}physiology.uu.se

Neurohypophyseal oxytocin (OT), secreted continuously under conditions of hyperosmolality, is a potent natriuretic hormone in rats. In contrast, OT secretion during lactation is pulsatile and is not accompanied by increased urinary Na⁺ excretion. The present experiments compared the effects of continuous and pulsatile infusion of OT on natriuresis in rats. In male rats anesthetized with Inactin, continuous infusion of OT (125 ng/kg·h) increased plasma OT to about 70 pg/ml; renal Na⁺ excretion increased 10-fold, and urine volume and K⁺ excretion also were elevated. However, when OT was administered iv in the same amount but in pulses given once every 5 or 10 min, to simulate the pattern of OT secretion during lactation, rats did not excrete significantly more urine, Na⁺, or K⁺ than did vehicle-treated animals. The plasma renin concentration, measured in these experiments because OT receptors are present in the macula densa, increased 2-fold when OT was infused either continuously or in pulses. These results indicate that the effects of OT administration on urinary Na⁺ excretion in rats varies depending on whether the infusion is pulsatile or continuous, whereas the effects of OT on renin secretion show no such difference.

This article has been cited by other articles:

				Z. K. Krowicki and D. R. Kapusta Tonic Nociceptinergic Inputs to Neurons in the Hypothalamic Paraventricular Nucleus Contribute to Sympathetic Vasomotor Tone and Water and Electrolyte Homeostasis in Conscious Rats J. Pharmacol. Exp. Ther., April 1, 2006; 317(1): 446 - 453. [Abstract] [Full Text] [PDF]

				N. Sabatier and G. Leng Presynaptic actions of endocannabinoids mediate {alpha}-MSH-induced inhibition of oxytocin cells Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2006; 290(3): R577 - R584. [Abstract] [Full Text] [PDF]

				W. Huang, M. Sjoquist, O. Skott, E. M. Stricker, and A. F. Sved Oxytocin antagonist disrupts hypotension-evoked renin secretion and other responses in conscious rats Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2001; 280(3): R760 - R765. [Abstract] [Full Text] [PDF]

				W. Huang, M. Sjoquist, O. Skott, E. M. Stricker, and A. F. Sved Oxytocin-induced renin secretion in conscious rats Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2000; 278(1): R226 - R230. [Abstract] [Full Text] [PDF]