Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

PROLACTIN AND LUTEINIZING HORMONE RECEPTORS IN MARSUPIAL CORPORA LUTEA: RELATIONSHIP TO CONTROL OF LUTEAL FUNCTION

PROLACTIN AND LUTEINIZING HORMONE RECEPTORS IN MARSUPIAL CORPORA LUTEA: RELATIONSHIP TO CONTROL... Prolactin and LH receptor concentrations in tammar wallaby corpora lutea (CL) have been examined and related to the control of luteal function in this and other marsupial species. During embryonic diapause, quiescent CL contained high concentrations of prolactin receptors. This was consistent with an earlier suggestion that prolactin may act directly on the CL to maintain its quiescent state. However, despite an apparent seasonal change in the mechanism by which the CL is maintained in quiescence, the number of luteal prolactin receptors remained constant throughout the year. Reactivation of quiescent CL led to an approximate halving of prolactin receptors on a per cell basis, but pregnancy had no effect. None of the wallaby CL showed any significant degree of LH binding, although wallaby follicles and testicular tissue did show binding. This lack of LH binding was consistent with previous findings that quiescent wallaby CL reactivate in response to hypophysectomy and are refractory to LH when cultured in vitro. Parturition, which occurs approximately 2 days before ovulation in this species, had no effect on numbers of either prolactin or LH receptors despite the occurrence of a peak of plasma prolactin at this time. The red kangaroo, which also exhibits embryonic diapause, showed a similar pattern of luteal receptor numbers with high prolactin and negligible LH binding, whereas the brush-tailed possum, which does not exhibit embryonic diapause, gave a pattern more like that seen in Eutheria with many more LH than prolactin receptors. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Endocrinology Bioscientifica

PROLACTIN AND LUTEINIZING HORMONE RECEPTORS IN MARSUPIAL CORPORA LUTEA: RELATIONSHIP TO CONTROL OF LUTEAL FUNCTION

Download PDF
10 pages

Loading next page...
 
/lp/bioscientifica/prolactin-and-luteinizing-hormone-receptors-in-marsupial-corpora-lutea-SfOvEFpa8V

References

References for this paper are not available at this time. We will be adding them shortly, thank you for your patience.

Publisher
Bioscientifica
Copyright
Copyright © 1982 The Authors. All Rights Reserved.
ISSN
0022-0795
eISSN
1479-6805
DOI
10.1677/joe.0.0920063
Publisher site
See Article on Publisher Site

Abstract

Prolactin and LH receptor concentrations in tammar wallaby corpora lutea (CL) have been examined and related to the control of luteal function in this and other marsupial species. During embryonic diapause, quiescent CL contained high concentrations of prolactin receptors. This was consistent with an earlier suggestion that prolactin may act directly on the CL to maintain its quiescent state. However, despite an apparent seasonal change in the mechanism by which the CL is maintained in quiescence, the number of luteal prolactin receptors remained constant throughout the year. Reactivation of quiescent CL led to an approximate halving of prolactin receptors on a per cell basis, but pregnancy had no effect. None of the wallaby CL showed any significant degree of LH binding, although wallaby follicles and testicular tissue did show binding. This lack of LH binding was consistent with previous findings that quiescent wallaby CL reactivate in response to hypophysectomy and are refractory to LH when cultured in vitro. Parturition, which occurs approximately 2 days before ovulation in this species, had no effect on numbers of either prolactin or LH receptors despite the occurrence of a peak of plasma prolactin at this time. The red kangaroo, which also exhibits embryonic diapause, showed a similar pattern of luteal receptor numbers with high prolactin and negligible LH binding, whereas the brush-tailed possum, which does not exhibit embryonic diapause, gave a pattern more like that seen in Eutheria with many more LH than prolactin receptors.

Journal

Journal of Endocrinology – Bioscientifica

Published: Jan 1, 1982

There are no references for this article.