Sertoli cells, proximal convoluted tubules in the kidney, and neurons in the brain contain cyclic protein-2.
We analyze by immunocytochemistry the in vivo distribution in rat Sertoli cells of Cyclic Protein-2 (CP-2), which is maximally synthesized and secreted in vitro at stages VI and VII of the cycle of the seminiferous epithelium. This analysis demonstrates that CP-2 staining is strongest in Sertoli cells in stage VI and VII tubules. Additionally, we demonstrate that the staining for CP-2 within a stage VII tubule differs from the staining of another Sertoli cell secretory product, androgen-binding protein. CP-2 is not detected by immunocytochemistry in any other tissues of the reproductive tract, though immunoblot analysis demonstrates the presence of CP-2 in rete testis and epididymal fluids. CP-2 was immunocytochemically detected in only three other organs: the kidney, the brain (with greatest concentration in the supraoptic and paraventricular nuclei), and the posterior pituitary. The presence of CP-2 in the kidney was confirmed by metabolic radiolabeling, immunoprecipitation, and peptide analysis. The presence of CP-2 in the brain was confirmed by immunoblot analysis of radioinert protein immunoprecipitated from the anterior hypothalamus.
Zabludoff
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SD
Department of Population Dynamics, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, Maryland 21205.
Erickson-Lawrence
M
M
Wright
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WW
D000727:Androgen-Binding Protein / Q000032:analysis; D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D004822:Epididymis / Q000032:analysis; D007668:Kidney / Q000032:analysis / Q000166:cytology; D007687:Kidney Tubules, Proximal / Q000032:analysis*; D008297:Male; D010904:Pituitary Gland, Posterior / Q000032:analysis; D011233:Precipitin Tests; D011467:Prostate / Q000032:analysis; D011506:Proteins / Q000032:analysis* / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains; D012152:Rete Testis / Q000032:analysis; D012669:Seminal Vesicles / Q000032:analysis; D012708:Sertoli Cells / Q000032:analysis* / Q000166:cytology; D014649:Vas Deferens / Q000032:analysis
D000727:Androgen-Binding Protein; D011506:Proteins