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Immunolocalization and expression of the steroidogenic acute regulatory protein during the transitional stages of rat follicular differentiation

Immunolocalization and expression of the steroidogenic acute regulatory protein during the transitional stages of rat follicular differentiation

Authors :
Winston E. Thompson
Kewlyn H. Thomas
Jacqueline M. Powell
Joseph A. Whittaker
Source :
The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society. 47(6)
Publication Year :
1999

Abstract

SUMMARY This study was designed to determine the pattern of expression and cellular distribution of the steroidogenic acute regulatory protein (StAR) during the transitional stages of follicular differentiation in rat ovary. Using specific antisera against the StAR, immunohistochemistry, Western blotting, and immunoprecipitation analyses provide evidence confirming the localization and expression of StAR in granulosa cells (GCs) of juvenile rat ovaries before and after PMSG treatment. The results also show that StAR expression occurs in theca intersitial cells surrounding preantral, antral, and larger antral follicles in adult diestrous ovaries. Furthermore, we have demonstrated heterogenous StAR immunoreactivity in the granulosa cell layers and cells of the corpora lutea. A novel finding presented here is that, during ongoing growth and differentiation of the follicle, the immunoreactivity of StAR tends to shift from the GC of early antral follicles to the theca cell layers in the adult. The spatiotemporal changes or shifts in StAR expression and cellular localization also coincide with the appearance of more acidic isoforms of the 30-kD protein, as determined by two-dimensional gel electrophoresis. Although the functional implications of these observations remain unclear, the acute temporal changes in StAR expression and localization may not only reflect the dynamic steroidogenic capacity of follicular cells but may also support a possible role for FSH in the induction of follicular maturation. (J Histochem Cytochem 47:769‐776, 1999)

Details

ISSN :
00221554
Volume :
47
Issue :
6
Database :
OpenAIRE
Journal :
The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society
Accession number :
edsair.doi.dedup.....73c187db24f8f51901d4c9d3cce0295e