Abstract
In several species the myometrium is quiescent shortly before parturition1. At this time high titres of relaxin are present in the plasma2 and there is evidence3 that the hormone has a direct inhibitory action on the uterine muscle. Relaxin could also contribute to uterine quiescence by inhibiting oxytocin release. To determine whether relaxin has a central action on the release of oxytocin, we have studied the effect of intravenous injections of porcine relaxin on milk ejection in the anaesthetized lactating rat. We report that reflex milk ejection was suppressed by relaxin in a dose-dependent manner, the onset of inhibition being rapid and lasting from 10 to 60 min. After the period of inhibition the normal temporal pattern of reflex milk ejection was resumed. Mammary sensitivity to exogenous or endogenous oxytocin was reduced by relaxin but not sufficiently to explain the effects observed. Furthermore, relaxin (1 µg per rat) injected into the cerebral ventricles profoundly disturbed the pattern of reflex milk ejection without affecting the response of the mammary gland to oxytocin. These results suggest a novel role for relaxin within the central nervous system. The site in the brain at which the effects of relaxin are exerted remains unknown.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Porter, D. G. in Biology of Relaxin and its Role in the Human (eds Bigazzi, M., Greenwood, F.C. & Gasparri, F.) 114–124 (Excerpta Medica, Amsterdam, 1983).
Porter, D. G. in Oxford Reviews of Reproductive Biology Vol. 1 (ed. Finn, C. A.) 1–57 (Clarendon, Oxford, 1979).
Bradshaw, J. M. C., Downing, S. J., Moffatt, A., Hinton, J. C. & Porter, D. G. J. Reprod. Fert. 63, 145–153 (1981).
Clarke, G., Fall, C. H. D., Lincoln, D. W. & Merrick, L. P. Br. J. Pharmac. 63, 519–528 (1978).
Lincoln, D. W., Hill, A. & Wakerley, J. B. J. Endocr. 57, 459–476 (1973).
Walsh, J. R. & Niall, H. D. Endocrinology 107, 1258–1260 (1980).
Wiqvist, N. Acta endocr., Copenh. 32, Suppl. 46, 15–32 (1959).
Voloschin. L. M. & Tramezzani, N. Endocrinology 105, 1202–1207 (1979).
Lincoln, D. W. et al. Expl Brain Res. 38, 151–162 (1980).
Porter, D. G., Downing, S. J. & Bradshaw, J. M. C. J. Endocr. 83, 183–192 (1979).
Knox, F. S. & Griffith, D. R. Proc. Soc. exp. Biol. Med. 133, 135–137 (1970).
Cowie, A. T., Cox, C. P., Folley, S. J., Hosking, Z. D. & Tindal, J. S. J. Endocr. 31, 165–172 (1965).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Summerlee, A., O'Byrne, K., Paisley, A. et al. Relaxin affects the central control of oxytocin release. Nature 309, 372–374 (1984). https://doi.org/10.1038/309372a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/309372a0
This article is cited by
-
Relaxin family peptide systems and the central nervous system
Cellular and Molecular Life Sciences (2010)
-
Comparison of relaxin receptors in rat isolated atria and uterus by use of synthetic and native relaxin analogues
British Journal of Pharmacology (1998)
-
A test for prorelaxin-processing enzymes using unmodified peptide substrates
Letters in Peptide Science (1995)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.
