The Inhibin B Response in Male Rats Treated with a GnRH Agonist and an Endothelin Receptor Antagonist
Article first published online: 24 JAN 2013
© 2013 Wiley Periodicals, Inc.
Birth Defects Research Part B: Developmental and Reproductive Toxicology
Special Issue: Part B: Developmental and Reproductive Toxicology
Volume 98, Issue 1, pages 82–90, February 2013
How to Cite
Coulson, M., Mitchard, T., Bickerton, S., Harris, J., Betts, C. and Stewart, J. (2013), The Inhibin B Response in Male Rats Treated with a GnRH Agonist and an Endothelin Receptor Antagonist. Birth Defects Research Part B: Developmental and Reproductive Toxicology, 98: 82–90. doi: 10.1002/bdrb.21044
- Issue published online: 5 FEB 2013
- Article first published online: 24 JAN 2013
- Manuscript Accepted: 12 DEC 2012
- Manuscript Received: 30 NOV 2012
- Inhibin B;
- Endothelin receptor
This study examined the correlation between Inhibin B and testicular pathology.
Male Han Wistar rats (approximately 10 weeks old) were administered either vehicle or an endothelin receptor antagonist (ET-An) orally for 28 days or a Gonadotropin Releasing Hormone (GnRH) agonist (GnRH-A) as a subcutaneous implant on day 1. Ten animals/group/time point were killed on days 4, 8, 15, and 29 (controls on days 15 and 29) for testes weights and histopathology. In-life blood samples were taken on days 4, 8, 15, and 29 to measure Inhibin B, Follicle-Stimulating Hormone (FSH), and Lutenising Hormone (LH), and at necropsy for the same hormones plus testosterone.
Plasma Inhibin B showed a wide concentration range in controls (group means 76.4–184.2 pg/ml; individual animals 17.8–381 pg/ml). GnRH-A caused decreased testes weights plus degenerative testicular pathology from day 4 with partial recovery by day 29. Statistically significant reductions in Inhibin B were observed at all time points and appeared to track the development and partial recovery of the pathology (generally <50 pg/ml on days 4–15; group mean 92 pg/ml on day 29). ET-An produced an increase in testes weights and a nondegenerative lesion of minimal tubular dilatation. There was a trend for lower Inhibin B values (30–50%) at all time points, including on day 4 when tubular dilatation was not yet evident.
Inhibin B showed a good correlation with testicular pathology for GnRH-A, and following ET-An administration appeared to give a signal that might reflect changes in tubular function in the absence of degenerative pathology.