Document Detail

Influence of synthetic lamprey GnRH-III on gonadotropin release and steroid hormone levels in gilts.
MedLine Citation:
PMID:  20708243     Owner:  NLM     Status:  In-Process    
Based on the supposition that lamprey GnRH-III (lGnRH-III) elicits FSH releasing activity in swine, synthetic lGnRH-III (peforelin, Maprelin® XP10) was used in puberal estrus synchronized gilts. The secretion of reproductive hormones FSH, LH, estradiol and progesterone was analyzed, and follicle growth and ovulation recorded. Altogether, 24 German Landrace gilts were treated after an 18-day long synchronization of the estrus cycle with Regumate® as follows: 48 h after the last Regumate® feeding they received im either 150 μg Maprelin® XP10 (lGnRH-III, group Maprelin, n = 6), 50 μg Gonavet Veyx® (GnRH-I agonist, group GnRH, n = 6), 850 IE Pregmagon® (eCG, group eCG, n = 6) or saline (group Control, n = 6). Additionally, in eight gilts the concentrations of FSH and LH were analyzed after treatment with 150 μg Maprelin® XP10 (n = 3), 50 μg Gonavet Veyx® (n = 3) or saline (n = 2) at mid-cycle (day 10 of the estrus cycle). Blood samples were collected via implanted jugular vein catheters. Ovarian features were judged endoscopically at the end of the Regumate® feeding and on days 5 and 6 after treatment. Maprelin® XP10 had no effect on FSH release in gilts; neither at the pre-ovulatory period or at mid-cycle. Furthermore, LH levels were unaffected. In contrast, GnRH-I agonist stimulates FSH release, however less compared to LH secretion. LH secretion was induced by GnRH-I both during the follicular phase and at mid-cycle. Equine CG did not stimulate the release of pituitary hormones FSH and LH due to its direct action on the ovary. Increased estradiol concentrations during days 2 to 5 after Regumate® in all treatment groups indicated pre-ovulatory follicle growth in gilts. Equine CG stimulated a higher (P < 0.01) number of ovulatory follicles compared to the other treatment groups. All together, 83 to 100 % of gilts ovulated by day 6 post treatment. In summary, results of our study on reproductive hormone secretion do not provide evidence that synthetic lGnRH-III (Maprelin® XP10) selectively releases FSH in estrus synchronized gilts.
Klaus-Peter Brüssow; Falk Schneider; Armin Tuchscherer; Wilhelm Kanitz
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Publication Detail:
Type:  Journal Article     Date:  2010-08-12
Journal Detail:
Title:  Theriogenology     Volume:  74     ISSN:  1879-3231     ISO Abbreviation:  Theriogenology     Publication Date:  2010 Dec 
Date Detail:
Created Date:  2010-11-01     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0421510     Medline TA:  Theriogenology     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1570-8     Citation Subset:  IM    
Copyright Information:
Copyright © 2010 Elsevier Inc. All rights reserved.
Department of Reproductive Biology, Leibniz Institute for Farm Animal Biology (FBN), 18196 Dummerstorf, Germany.
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