Contrasting levels of transferrin gene activity in cultured rat Sertoli cells and intact seminiferous tubules.
AUTOR(ES)
Lee, N T
RESUMO
Two-dimensional polyacrylamide gel electrophoresis of proteins and transfer blot hybridization of RNA have been used to study the activity and expression of the rat transferrin gene in cultured Sertoli cells and in whole testis and isolated seminiferous tubules of sexually immature and mature rats. Although the transferrin gene in cultured Sertoli cells is actively engaged in the transcription of mRNA and the mRNA is translated into a secretory product, little transferrin mRNA and transferrin protein are present in whole testes and isolated seminiferous tubules. Sertoli cells upon culturing show a time-dependent transferrin gene activation, and abundant transferrin mRNA can be detected 6 hr after plating. A similar study using intact seminiferous tubular segments from the same rats failed to show a comparable temporal activation of the transferrin gene. Results of this study, together with previous experimental data, suggest that Sertoli cells in vivo are most likely not actively engaged in the synthesis of a testicular transferrin but, instead, rely mainly on plasma transferrin contributed by the liver. In vitro, Sertoli cells, released from the physiological constraints that operate in vivo, rapidly activate the transferrin gene, resulting in abundant newly synthesized Sertoli cell transferrin product.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=386890Documentos Relacionados
- Calcium and potassium currents in spermatogenic cells dissociated from rat seminiferous tubules.
- Sertoli cells and various types of multinucleates in the rat seminiferous tubules following temporary ligation of the testicular artery.
- On the ultrastructure of modified Sertoli cells in the terminal segment of seminiferous tubules in the boar.
- Modulation of renal sodium-potassium-adenosine triphosphatase by aldosterone. Effect of high physiologic levels on enzyme activity in isolated rat and rabbit tubules.
- Hormonal regulation of protein synthesis, secretion, and phosphorylation in cultured rat Sertoli cells.