Biology of Reproduction, Vol 21, 69-74, Copyright © 1979 by Society for the Study of Reproduction

Cytophotometric Measurements of DNA, RNA and Basic Protein in FSH Treated Rat Sertoli Cells in Culture

¹ Biology Department, The Pennsylvania State University, University Park, Pennsylvania 16802
² Department of Physiology and Cell Biology, University of Kansas, Lawrence, Kansas 66045

Immature rat Sertoli cells form colonies in response to follicle stimulating hormone (FSH). The levels of nuclear DNA, RNA and basic protein in 24 h cultures of 15-day-old rat testicular cells were quantitated cytophotometrically using Feulgen, azure B and fast green stains. Sertoli cells were identified by the presence of satellite karyosomes and by growth morphology; Leydig cells and fibroblasts were identified by growth pattern. Follicle stimulating hormone was found to increase nuclear basic proteins as well as Feulgen acid hydrolysis properties of Sertoli cell DNA. Feulgen DNA staining was higher in FSH treated Sertoli cells. This increase was not caused by cell cycling since G₂ DNA levels were low (0.2%) and no increase in number of G₂ cells was noted at 48 or 72 h of culture, suggesting the metabolic stimulation of previously quiescent nuclei rather than the induction of cycling. Mean and modal Feulgen-DNA were seen to be correlated with colonies (groups) of cells as well as hormone treatment. FSH had no effect on DNA, RNA or basic protein content of cocultured fibroblasts or Leydig cells. Taken together, the results indicate that FSH stimulation of colony formation is related to Sertoli cell-specific metabolic activity as measured by nuclear DNA, RNA and basic protein levels.

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ACKNOWLEDGMENTS This work was supported in part by contract NO1-HD-3-2794 and by grant 5-ROI-HD-10953, from NICHD and by the Kansas General Research Fund. We thank the NIAMDD for the gift of NIHOFSH-S₁₂.