Function of interleukin-6 as an inhibitor of meiotic DNA synthesis in the rat seminiferous epithelium.
Interleukin-6 bioactivity (IL-6) has been shown to be present in Sertoli cells. To further characterize the IL-6 in the seminiferous epithelium, the IL-6 like-antigen was detected, stage-specific basal distribution of IL-6-like bioactivity and its regulation by FSH, cAMP and TPA was characterized in isolated, rat seminiferous tubule segments. In addition, the effects of human recombinant IL-6 on stage-specific DNA synthesis was investigated. Both monoclonal and polyclonal antibodies recognized M(r) 22 and 23 kDa of IL-6 like immunoreactivity in the seminiferous epithelium. The basal IL-6 production showed high levels during stages XIII-XIV-I-V, low during VII and VIII. FSH stimulated IL-6 production at nearly all stages and most significantly at stage VII of the cycle. Human recombinant IL-6 dose-dependently inhibited the onset of meiotic DNA synthesis of preleptotene spermatocytes, and a minor inhibition was found on advanced (A3-type B) spermatogonia. These results support the hypothesis that IL-6 is a stage-specific paracrine regulator of the seminiferous epithelium exerting a specific inhibitory action on meiotic DNA synthesis.
Hakovirta
H
H
Department of Anatomy, University of Turku, Finland.
Syed
V
V
Jégou
B
B
Parvinen
M
M
D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis / Q000494:pharmacology / Q000502:physiology*; D008297:Male; D008540:Meiosis; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000494:pharmacology; D012671:Seminiferous Tubules / Q000166:cytology / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D015850:Interleukin-6; D011994:Recombinant Proteins; D003994:Bucladesine; D005640:Follicle Stimulating Hormone; D004247:DNA; D013755:Tetradecanoylphorbol Acetate