title: Basal and FSH-stimulated steady state levels of SGP-2, alpha 2-macroglobulin, and testibumin in culture media of rat seminiferous tubules at defined stages of the epithelial cycle.
abstract: Production of several proteins by rat Sertoli cells is dependent on the stage of the cycle of the seminiferous epithelium. The authors have determined steady state levels and follicle-stimulating hormone responsiveness of three Sertoli cell products in culture media of rat seminiferous tubule segments at different stages of the epithelial cycle: SGP-2 (sulfated glycoprotein-2), alpha 2-macroglobulin, and testibumin. Basal SGP-2 levels were twofold higher in stages VII through VIII compared with stages XIII to I to VI (P less than 0.05). Highest basal alpha 2-macroglobulin levels were found in stages II through VIII; this was about 35% greater than in stages XIII through I of the cycle (P less than 0.05). Basal testibumin levels were twofold higher in stages II through VI compared with stages IX through XII of the cycle. Follicle-stimulating hormone had no effect on SGP-2, but by contrast it (50 mg/L) increased the level of alpha 2-macroglobulin significantly (P less than 0.05) in stages XIII through I. Follicle-stimulating hormone treatment (10 mg/L) elevated testibumin levels at each stage-pool by about 40% (P less than 0.05). The current results using staged tubular segments in vitro demonstrate cyclic basal steady-state levels of the three proteins along the seminiferous tubules and follicle-stimulating hormone regulation of alpha 2-macroglobulin and testibumin.
authors.affiliation: Department of Anatomy, University of Turku, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Kangasniemi
authors.forename: C Y
authors.initials: CY
authors.lastname: Cheng
authors.forename: J
authors.initials: J
authors.lastname: Toppari
authors.forename: J
authors.initials: J
authors.lastname: Grima
authors.forename: M
authors.initials: M
authors.lastname: Stahler
authors.forename: C W
authors.initials: CW
authors.lastname: Bardin
authors.forename: M
authors.initials: M
authors.lastname: Parvinen
mesh_terms: D000818:Animals; D051152:Clusterin; D005640:Follicle Stimulating Hormone / Q000502:physiology*; D006023:Glycoproteins / Q000032:analysis*; D008297:Male; D018832:Molecular Chaperones; D011506:Proteins / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains; D049231:Saposins; D012671:Seminiferous Tubules / Q000737:chemistry*; D013091:Spermatogenesis; D000511:alpha-Macroglobulins / Q000032:analysis*
chemical_list: D051152:Clusterin; D006023:Glycoproteins; D018832:Molecular Chaperones; D011506:Proteins; C483347:Psap protein, rat; D049231:Saposins; D000511:alpha-Macroglobulins; D005640:Follicle Stimulating Hormone