Control of the koala (Phascolarctos cinereus) anterior pituitary-godadal axis with analogues of GnRH

Allen, Camryn D., Burridge, Michelle, Chafer, Mandy L., Nicolson, Vere N., Jago, Sophia C., Booth, Rosemary L., Fraser, Grant, Ensabella, Traza-Jade, Zee, Yeng Peng, Lundie-Jenkins, Geoff, Holt, William V., Lisle, Allan T., Carrick, Frank N., Curlewis, Jonathan D., D'Occhio, Michael J. and Johnston, Stephen D. (2008) Control of the koala (Phascolarctos cinereus) anterior pituitary-godadal axis with analogues of GnRH. Reproduction Fertility And Development, 20 5: 598-605. doi:10.1071/RD07214

Author Allen, Camryn D.
Burridge, Michelle
Chafer, Mandy L.
Nicolson, Vere N.
Jago, Sophia C.
Booth, Rosemary L.
Fraser, Grant
Ensabella, Traza-Jade
Zee, Yeng Peng
Lundie-Jenkins, Geoff
Holt, William V.
Lisle, Allan T.
Carrick, Frank N.
Curlewis, Jonathan D.
D'Occhio, Michael J.
Johnston, Stephen D.
Title Control of the koala (Phascolarctos cinereus) anterior pituitary-godadal axis with analogues of GnRH
Journal name Reproduction Fertility And Development   Check publisher's open access policy
ISSN 1031-3613
Publication date 2008-01-01
Sub-type Article (original research)
DOI 10.1071/RD07214
Open Access Status DOI
Volume 20
Issue 5
Start page 598
End page 605
Total pages 8
Editor Sharon Mortimer
Place of publication Collingwood, VIctoria Australia
Publisher CSIRO Pubishing
Language eng
Subject C1
070206 Animal Reproduction
970106 Expanding Knowledge in the Biological Sciences
Abstract The aim of the present study was to determine whether analogues of gonadotrophin-releasing hormone (GnRH) could be used to both induce an acute testosterone response and suppress anterior pituitary function in male koalas, and induce a luteal phase in female koalas. Experiment 1 characterised the steroidogenic response of male koalas to administration of 30 μg (4.3 μg kg–1) natural-sequence GnRH. Intra-muscular injection of natural-sequence GnRH induced the release of LH and testosterone with peak concentrations at 30 min (3.7 ± 1.9 ng mL–1) and 2 h (5.4 ± 0.5 ng mL–1), respectively. In Experiment 2, a single injection of the GnRH antagonist acyline (100 μg (14.3 μg kg–1) or 500 μg (71.4 μg kg–1)) did not influence the testosterone response to subsequent injections of natural-sequence GnRH. In Experiment 3, 4 μg (~0.67 μg kg–1) of the GnRH agonist buserelin induced a luteal phase in five female koalas based on a LH surge, secretion of progestogen, and a normal-length oestrous cycle. The findings have shown that (1) natural-sequence GnRH can be used to test gonadotroph cell function and determine the testosterone-secreting capacity of male koalas, (2) the GnRH antagonist, acyline, at the dose rates used, does not suppress the pituitary-testis axis in male koalas, and (3) the GnRH agonist, buserelin, induces a normal luteal phase in female koalas.
Keyword acyline
GnRH agonist
GnRH antagonist
natural-sequence GnRH
Q-Index Code C1
Q-Index Status Confirmed Code

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Agriculture and Food Sciences
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Created: Tue, 31 Mar 2009, 20:33:36 EST by Mrs Kathy Bachmann on behalf of School of Animal Studies