| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Geriatric Research, Education and Clinical Center, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304
1 To whom correspondence should be addressed. e-mail: eve.reaven{at}med.va.gov
This study examined the in vivo relationship between expression of the HDL receptor scavenger receptor class B (SR-BI) and corresponding structural changes in the rat adrenocortical cell microvillar compartment. Using hormonal stimulation and withdrawal protocols, we were able to manipulate adrenal SR-BI levels and carry out qualitative and quantitative measurements correlating SR-BI expression with microvillar mass and microvillar channel formation. Young male rats were used as controls or treated with adrenocorticotropin hormone (ACTH) (24 h), 17
-ethinyl estradiol (17-E2) (5 days), or dexamethasone (DEX) (24 h). Quantitative Western blot analysis and immunocytochemistry indicated that ACTH and 17-E2 treatment greatly increased SR-BI expression in the adrenal (especially in the microvillar compartment of adrenocortical cells), whereas DEX treatment led to a decrease of SR-BI by all measurements. At the same time, striking ultrastructural changes occurred in the adrenocortical cell microvillar compartment: e.g., microvillar area and microvillar channel formation and complexity dramatically increased (compared with control values) after ACTH or 17-E2 treatment, whereas the same values declined after DEX treatment.
These measurements illustrate the exceptional flexibility and responsiveness of the microvillar compartment to hormonal stimuli, and suggest that regulation of SR-BI expression and structural configuration of the surface of steroidogenic cells goes hand in hand.
Abbreviations: ACTH, adrenocorticotropin hormone; CRF, corticotropin-releasing factor; DEX, dexamethasone; SR-BI, scavenger receptor class B type I; 17-E2, 17-ethinyl estradiol
Supplementary key words SR-BI • HDL • steroid hormone • ACTH • corticosterone • cholesterol • 17-ethinyl estradiol • steroidogenesis
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  S. Parathath, Y. F. Darlington, M. de la Llera Moya, D. Drazul-Schrader, D. L. Williams, M. C. Phillips, G. H. Rothblat, and M. A. Connelly Effects of amino acid substitutions at glycine 420 on SR-BI cholesterol transport function J. Lipid Res., June 1, 2007; 48(6): 1386 - 1395. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. D. Akpovi, S. R. Yoon, M. L. Vitale, and R-M. Pelletier The predominance of one of the SR-BI isoforms is associated with increased esterified cholesterol levels not apoptosis in mink testis J. Lipid Res., October 1, 2006; 47(10): 2233 - 2247. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Reaven, Y. Cortez, S. Leers-Sucheta, A. Nomoto, and S. Azhar Dimerization of the scavenger receptor class B type I: formation, function, and localization in diverse cells and tissues J. Lipid Res., March 1, 2004; 45(3): 513 - 528. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Rigotti, H. E. Miettinen, and M. Krieger The Role of the High-Density Lipoprotein Receptor SR-BI in the Lipid Metabolism of Endocrine and Other Tissues Endocr. Rev., June 1, 2003; 24(3): 357 - 387. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Liu and M. Krieger Highly Purified Scavenger Receptor Class B, Type I Reconstituted into Phosphatidylcholine/Cholesterol Liposomes Mediates High Affinity High Density Lipoprotein Binding and Selective Lipid Uptake J. Biol. Chem., September 6, 2002; 277(37): 34125 - 34135. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Journal of Biological Chemistry |
| Molecular and Cellular Proteomics | ASBMB Today |
