title: c-fos protein expression in apoptotic rat spermatocytes induced by gossypol.
abstract: Proto-oncogene products such as c-fos protein with a molecular weight of 62 kDa have been identified in rat spermatocytes. In this study, cellular levels of c-fos proteins in spermatocyte, either with or without gossypol exposure, were quantitatively detected by Western immunoblot and a computer-controlled Spot-denso-program with an IS-1000 Digital Imaging System. Within 0.5-3.5 h (an average of 2 h) of the addition of gossypol, levels of c-fos proteins fell dramatically. The reduction in c-fos proteins occurred 6 h before the apoptosis of spermatocytes in the presence of gossypol. Four hours after exposure to gossypol, the c-fos protein content was overexpressed. The period of c-fos up-regulation lasted for approximately 8 h. The increase in c-fos protein coincided with a high rate of apoptotic cell death. Morphologic structure of the dying cell was revealed by electron microscopy. These results suggest that spermatocyte apoptosis induced by gossypol correlates with biphasic c-fos protein-mediated apoptosis.
authors.affiliation: Department of Anatomy, Physiological Sciences and Radiology, North Carolina State University, Raleigh 27606, USA.
authors.forename: C S
authors.initials: CS
authors.lastname: Teng
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D015153:Blotting, Western; D002478:Cells, Cultured; D015536:Down-Regulation; D004591:Electrophoresis, Polyacrylamide Gel; D006072:Gossypol / Q000494:pharmacology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D000090063:Proto-Oncogene Mas; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013090:Spermatocytes / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D015854:Up-Regulation
chemical_list: C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D016760:Proto-Oncogene Proteins c-fos; D006072:Gossypol