Post-natal Changes in Testicular Concentrations of Interleukin-1 Alpha and Beta and Interleukin-6 during Sexual Maturation in Bulls

Abstract

Based on observations in laboratory animals interleukins could be regulators of testicular development. The objects of this study were to see if interleukins (IL-1 and IL-6) are present in the developing bull testis and to establish the temporal patterns of concentrations of IL-1 and IL-6 in the bovine testis during development. Separate groups of six bull calves were castrated every 4 weeks from 5 to 33 weeks of age, and at 56 weeks of age. Mean testicular IL-1 alpha concentrations decreased (p < 0.01) from 5 to 9 weeks of age and 13 to 21 weeks of age. Mean testicular IL-1 beta concentrations decreased (p < 0.01) from 13 to 17 weeks of age and from 29 to 33 weeks of age. Mean IL-1 bioactivity increased from 13 to 17 weeks of age, decreased to 21 weeks, increased to 25 weeks, decreased to 29 weeks and decreased from 33 to 56 weeks of age (p < 0.05). Mean testicular IL-6 concentrations decreased (p < 0.05) from 9 to 13 weeks of age, increased (p < 0.05) to 21 weeks, decreased (p < 0.05) to 25 weeks, increased (p < 0.05) to 29 weeks and decreased (p < 0.01) to 56 weeks of age. In conclusion, testicular IL-1 alpha, IL-1 beta and IL-6 were found in the bovine testis and concentrations were age dependent. Testicular IL-1 alpha and IL-1 beta concentrations were highest in the early post-natal period; however, IL-1 bioactivity and IL-6 concentrations were greatest in the immediate pre-pubertal period. These findings suggest a functional role for interleukins in testicular development in the bull.

β-Defensins: Farming the Microbiome for Homeostasis and Health

“…The blood-testis barrier is maintained by several types of cell junctions, which limit the access of systemic immune contents to the inner reproductive compartments (225). Cytokines and chemokines are expressed in healthy tissue and function during normal testicular development (226), and increased concentrations of inflammatory cytokines have been associated with increased reactive oxygen species and histone abnormalities in sperm (227). Whereas, levels of the anti-inflammatory cytokine IL-10 in bull seminal fluid is positively associated with sperm motility, inverse correlations was detected with proinflammatory cytokines (228).…”

The Effects of Interleukin‐6 Signal Blockade on Immune System, Reproductive and Skeletal Development in Juvenile Mice

“…Regarding spermatogenesis, IL‐6 has been suggested to exert adverse effects on the male reproductive function, inducing suppression of Leydig cell steroidogenesis and/or persistent testicular resistance to luteinizing hormone action in healthy men (Tsigos et al, ; Bornstein et al, ). Previously reported age‐dependent (Potashnik et al, ; Bagu et al, ) and/or testicular stage‐dependent (Hakovirta et al, ) alterations in IL‐6 level may raise the hypothesis that IL‐6 has a suppressive role in the process of testicular development and/or spermatogenesis at specific times. However, when the whole body systems, including Leydig cells in the interstitium and basal lamina of Sertoli cells within the testes, were exposed to the IL‐6R neutralizing antibody during the juvenile period, no biologically important changes were detected in sperm evaluations.…”

“…IL‐6 expression, in terms of protein and mRNA levels, has been reported to be higher in the testicular tissues of sexually immature mice compared with adult mice (Potashnik et al, ), and the testicular IL‐6 concentration varies in an age‐dependent manner in bulls (Bagu et al, ). Although previous reports indicate involvement of IL‐6 in testicular development, no noteworthy effects were detected on male sexual maturity parameters, including histopathology of male reproductive organs, in normal mice that were administered MR16‐1 in our study.…”