help button home button Endocrine Society Endocrinology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Copyright Permission
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Steinetz, B. G.
Right arrow Articles by Lust, G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Steinetz, B. G.
Right arrow Articles by Lust, G.

Endocrinology, Vol 127, 1057-1063, Copyright © 1990 by Endocrine Society

ARTICLES

Diurnal variation of serum progesterone, but not relaxin, prolactin, or estradiol-17 beta in the pregnant bitch

BG Steinetz, LT Goldsmith, SH Hasan and G Lust
New York University Medical Center, Laboratory for Experimental Medicine and Surgery in Primates, Tuxedo, New York 10987.

The concentrations of progesterone (P), relaxin (Rlx), estradiol (E2) and PRL were measured by specific RIAs in serum samples collected twice daily at 8:00 am and 3:00 pm at weekly intervals after mating and until whelping in five Labrador Retriever bitches. From weeks 3 to 6 of pregnancy, P exhibited a conspicuous and statistically significant diurnal pattern (P less than 0.05), its serum concentration being approximately twice as high at 8:00 am as at 3:00 pm. A similar but nonsignificant trend was observed weeks 2, 7, and 8, and the overall ratio of the am/pm P concentrations was 2.4 +/- 0.28 (P less than 0.001). Rlx, E2, and PRL did not show a diurnal pattern at any time during pregnancy. The glandular sources and regulation of secretion of Rlx were further investigated. Rlx bioactivity was detected in canine placentas and ovaries, providing supportive evidence that these organs may be a dual source of the hormone in canine pregnancy. Injection of ovine PRL in three pseudopregnant bitches significantly increased serum P concentration as compared with seven untreated pseudopregnant controls, but Rlx was not detectable in serum before, during or after PRL treatment. The data support the view that Rlx and P are independently regulated in the bitch; PRL may be a regulator of P, but not of Rlx secretion. However, as PRL showed no diurnal changes in concentration, it does not appear to be directly responsible for the diurnal pattern exhibited by P.


This article has been cited by other articles:


Home page
 Biol. Reprod.Home page
T. Klonisch, J. Kauffold, K. Steger, M. Bergmann, R. Leiser, B. Fischer, and S. Hombach-Klonisch
Canine Relaxin-Like Factor: Unique Molecular Structure and Differential Expression Within Reproductive Tissues of the Dog
Biol Reprod, February 1, 2001; 64(2): 442 - 450.
[Abstract] [Full Text]

Home page
 Biol. Reprod.Home page
T. Klonisch, S. Hombach-Klonisch, C. Froehlich, J. Kauffold, K. Steger, B.G. Steinetz, and B. Fischer
Canine Preprorelaxin: Nucleic Acid Sequence and Localization within the Canine Placenta
Biol Reprod, March 1, 1999; 60(3): 551 - 557.
[Abstract] [Full Text]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Endocrinology Endocrine Reviews J. Clin. End. & Metab.
Molecular Endocrinology Recent Prog. Horm. Res. All Endocrine Journals
Copyright © 1990 by The Endocrine Society