INSL3 Variation in Dogs Following Suppression and Recovery of the HPG Axis

Anand-Ivell, Ravinder; Coutinho, Acacia Rebello; Dai, Yanzhenzi; England, Gary; Goericke-Pesch, Sandra; Ivell, Richard

Abstract

Insulin-like peptide 3 (INSL3) is a constitutive product of mature, adult-type Leydig cells of the testes and consequently in most mammals is an ideal biomarker with which to monitor pubertal development. A new heterologous time-resolved fluorescence immunoassay was developed and validated to measure circulating INSL3 in the blood of adult male dogs. Compared to other species, INSL3 concentration is low with marked variation between individuals, which appears to be independent of breed, age, or weight. A model system was then used in which a cohort of beagle dogs was subject to a GnRH-agonist implant to suppress the HPG axis and spermatogenesis, followed by implant removal and recovery. Unlike testosterone, INSL3 levels were not fully suppressed in all animals by the GnRH agonist, nor was the recovery of Leydig cell function following implant removal uniform or complete, even after several weeks. In dogs, and dissimilar from other species (including humans), Leydig-cell INSL3 appears to be quite variable between individual dogs and only weakly connected to the physiology of the HPG axis after its suppression by a GnRH-agonist implant and recovery. Consequently, INSL3 may be less useful in this species for the assessment of testis function.

Citation

Anand-Ivell, R., Coutinho, A. R., Dai, Y., England, G., Goericke-Pesch, S., & Ivell, R. (2024). INSL3 Variation in Dogs Following Suppression and Recovery of the HPG Axis. Animals, 14(5), Article 675. https://doi.org/10.3390/ani14050675

• Journal Article Type: Article
• Acceptance Date: Feb 18, 2024
• Online Publication Date: Feb 21, 2024
• Publication Date: 2024-03
• Deposit Date: Feb 21, 2024
• Publicly Available Date: Feb 21, 2024
• Journal: Animals
• Electronic ISSN: 2076-2615
• Publisher: MDPI
• Peer Reviewed: Peer Reviewed
• Volume: 14
• Issue: 5
• Article Number: 675
• DOI: https://doi.org/10.3390/ani14050675
• Keywords: INSL3; male contraception; GnRH implant; HPG axis; canine
• Public URL: https://nottingham-repository.worktribe.com/output/31610964
• Publisher URL: https://www.mdpi.com/2076-2615/14/5/675
• Additional Information: © 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).