J. Anim Sci.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
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 reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Schmitt, E. J.
Right arrow Articles by Thatcher, W. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Schmitt, E. J.
Right arrow Articles by Thatcher, W. W.

Journal of Animal Science, Vol 74, Issue 8 1915-1929, Copyright © 1996 by American Society of Animal Science

JOURNAL ARTICLE

A cellular and endocrine characterization of the original and induced corpus luteum after administration of a gonadotropin-releasing hormone agonist or human chorionic gonadotropin on day five of the estrous cycle

E. J. Schmitt, C. M. Barros, P. A. Fields, M. J. Fields, T. Diaz, J. M. Kluge and W. W. Thatcher
Department of Dairy and Poultry Sciences, University of Florida, Gainesville 32611, USA.

To determine whether injection of hCG or GnRH-agonist on d 5 after estrus (d 0) has a differential functional effect on an induced and the original corpus luteum (CL), two experiments were conducted. In Exp. 1, nonlactating Holstein cows were injected on d 5 with saline (n = 4; T1), a GnRH-agonist (Buserelin, 8 micrograms i.m.; n = 4; T2), or hCG (1,000 i.u., i.v., and 2,000 i.u., i.m.; n = 4; T3). Induced CL were removed on d 13 and weights were different (GnRH-agonist < hCG). In vitro production of progesterone by CL tissue (microgram/g; microgram/CL) was affected by treatment (GnRH-agonist < hCG) and dose of LH (ng.mL) in culture media. Experiment 2 was a replicate of Exp. 1, except that the original CL was removed on d 17 for in vitro culture. Day-17 CL weights and in vitro production of progesterone by original CL were not affected by treatment. The daily rate of increase of plasma progesterone from d 6 to d 13 differed: saline < GnRH-agonist < hCG (P < .01). From d 14 to 17, the rate of plasma progesterone decrease was not different between treatments. Electron micrographic study of the original and induced CL indicates that LH-like exposure delays involution of steroidogenic luteal cells. In summary, the higher levels of progesterone from d 6 to d 13 of the estrous cycle following an injection of hCG vs GnRH-agonist on d 5 is due to a greater response of hCG-induced CL.


This article has been cited by other articles:


Home page
 J DAIRY SCIHome page
K. N. Galvao, J. E. P. Santos, A. C. Coscioni, S. O. Juchem, R. C. Chebel, W. M. Sischo, and M. Villasenor
Embryo survival from gossypol-fed heifers after transfer to lactating cows treated with human chorionic gonadotropin.
J Dairy Sci, June 1, 2006; 89(6): 2056 - 2064.
[Abstract] [Full Text] [PDF]

Home page
 J ANIM SCIHome page
R. N. Funston, R. J. Lipsey, T. W. Geary, and A. J. Roberts
Effect of administration of human chorionic gonadotropin after artificial insemination on concentrations of progesterone and conception rates in beef heifers
J Anim Sci, June 1, 2005; 83(6): 1403 - 1405.
[Abstract] [Full Text] [PDF]

Home page
 Biol. Reprod.Home page
T.L. Davis, M.L. Mussard, H. Jimenez-Severiano, W.J. Enright, and J.E. Kinder
Chronic Treatment with an Agonist of Gonadotropin-Releasing Hormone Enhances Luteal Function in Cattle
Biol Reprod, August 1, 2003; 69(2): 398 - 403.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1996 by the American Society of Animal Science.