Effect of a gonadotrophin-releasing hormone antagonist on luteinising hormone secretion and early pregnancy in gilts
The aims of the present study were: (1) to determine the duration of suppression of luteinising hormone (LH) following a single treatment with a gonadotrophin-releasing hormone (GnRH) antagonist (BIM-21009; Biomeasure) at a dose of 100 microg kg(-1); (2) to block LH pulses only for certain days of p...
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Published in | Reproduction fertility and development Vol. 15; no. 7-8; p. 451 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Australia
01.01.2003
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Subjects | |
Online Access | Get more information |
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Summary: | The aims of the present study were: (1) to determine the duration of suppression of luteinising hormone (LH) following a single treatment with a gonadotrophin-releasing hormone (GnRH) antagonist (BIM-21009; Biomeasure) at a dose of 100 microg kg(-1); (2) to block LH pulses only for certain days of pregnancy; and (3) to determine the period of early pregnancy most susceptible to suppression of LH. Three groups of gilts were injected with 100 microg kg(-1) on Day 16 (n = 5), 14 (n = 6) or 19 (n = 4) of pregnancy. Blood for LH analysis was collected at 20-min intervals for 12 h on the day before treatment and during varying stages of early pregnancy. Blood for progesterone analysis was collected daily and development of pregnancy was followed using real-time ultrasound. Prior to treatment, gilts had 2.6 +/- 0.7 LH pulses per 12 h. The GnRH antagonist abolished LH pulses for a period of 2.7 +/- 1.8 days and, thereafter, suppressed the resumed LH pulses (P < 0.05). Pregnancy was disrupted in three pigs (20%) with a mean treatment-to-abortion period of 4.7 days concurrent with a mean treatment-to-progesterone decline interval of 4.3 days. In a proportion of pigs, short-term LH suppression may cause early disruption of pregnancy. |
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ISSN: | 1031-3613 |
DOI: | 10.1071/RD03050 |