title: Regulated production of activin A and inhibin B throughout the cycle of the seminiferous epithelium in the rat.
abstract: Production and regulation of activin A and inhibin B during the cycle of the seminiferous epithelium were investigated in adult rats. Immunohistochemistry localised the activin beta(A)-subunit to the Sertoli cell cytoplasm, with much weaker expression in spermatocytes and spermatids. Both activin A and inhibin B, measured by ELISA were secreted by, seminiferous tubule fragments over 72 h in culture. Activin A was secreted in a cyclic manner with peak secretion from tubules isolated at stage VIII. Tubules collected during stage VI produced the least activin A. Inhibin B secretion was highest from stage IX-I tubules and lowest from stage VII tubules. Addition of interleukin-1beta (IL-1beta) had relatively little effect on activin A or inhibin B secretion in culture. In contrast, the peak secretion of activin A by stage VIII tubules was blocked by co-incubation with an excess of human recombinant IL-1 receptor antagonist, whereas inhibin B secretion increased slightly. Dibutyryl cAMP stimulated activin A secretion by late stage VII and VIII tubules and stimulated inhibin B across all stages. These data indicate that activin A and inhibin B are cyclically regulated within the seminiferous epithelium, with endogenous IL-1 (presumably IL-1alpha produced by the Sertoli cells), responsible for a peak of activin A production subsequent to sperm release at stage VIII. These data provide direct evidence that production of activin A and inhibin B by the Sertoli cell is locally modulated by IL-1alpha , in addition to FSH/cAMP, under the influence of the developing spermatogenic cells.
authors.affiliation: Monash Institute of Medical Research, Monash University, 27-31 Wright Street, Clayton, Victoria 3168, Australia.
authors.forename: Y
authors.initials: Y
authors.lastname: Okuma
authors.forename: A E
authors.initials: AE
authors.lastname: O'Connor
authors.forename: T
authors.initials: T
authors.lastname: Hayashi
authors.forename: K L
authors.initials: KL
authors.lastname: Loveland
authors.forename: D M
authors.initials: DM
authors.lastname: de Kretser
authors.forename: M P
authors.initials: MP
authors.lastname: Hedger
mesh_terms: D028341:Activins / Q000032:analysis / Q000096:biosynthesis*; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D003593:Cytoplasm / Q000737:chemistry; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D007150:Immunohistochemistry / Q000379:methods; D007265:Inhibins / Q000032:analysis / Q000096:biosynthesis; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000378:metabolism; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012670:Seminiferous Epithelium / Q000737:chemistry / Q000378:metabolism*; D012708:Sertoli Cells / Q000737:chemistry; D012795:Sialoglycoproteins / Q000494:pharmacology; D013091:Spermatogenesis / Q000502:physiology*; D013094:Spermatozoa / Q000737:chemistry; D013268:Stimulation, Chemical; D046509:Tissue Culture Techniques
chemical_list: C507763:IL1RN protein, human; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D012795:Sialoglycoproteins; C422405:activin A; C422364:inhibin B; D028341:Activins; D007265:Inhibins; D003994:Bucladesine