[Membrane testosterone receptors in cultured vascular smooth muscle cells].
OBJECTIVE
To determine the presence of membrane testosterone receptors in cultured vascular smooth muscle cells (VSMC), and investigate their relationship with classical intracellular androgen receptors (iAR).


METHODS
VSMCs were cultured from the thoracic aorta of male Sprague-Dawley rats by the explant method. Subconfluent VSMCs were incubated with serum-free medium for 24 h to obtain quiescent non-dividing cells, and then treated with the indicated agents. The aliquots of VSMCs were labeled with testosterone-BSA-FITC (T-BSA-FITC) and analyzed by flow cytometry. Classical iARs in intact- and permeabilized-cells were detected with anti-iAR antibodies and FITC-labeled secondary antibodies by immunofluorescence, followed by flow cytometry analysis.


RESULTS
Incubation of VSMCs with T-BSA-FITC obviously increased their relative fluorescence intensity at 10 sec as compared with the untreated controls (P < 0.01), and so did it at 10 min in comparison with the treatment with BSA-FITC alone or together with free testosterone (P < 0.01). Pretreatment with iAR antagonist flutamide exhibited no significant influence on the relative fluorescence intensity of VSMCs (P = 0.318). Traditional iARs were not detectable on the surface of intact VSMCs, although permeabilized cells contained iARs.


CONCLUSIONS
VSMCs contain testosterone receptors in the plasma membrane, and these membrane receptors are not identical to classical iARs.
Ma
Rui
R
Department of Cardiology, Nanjing General Hospital of Nanjing Military Region, Nanjing, Jiangsu 210002, China. rui_ma@126.com
Jiang
Shi-sen
SS
Cheng
Xun-min
XM
Gong
Jian-bin
JB
Zhang
Qi-gao
QG
Lin
Qi-shui
QS
D000818:Animals; D002478:Cells, Cultured; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011944:Receptors, Androgen / Q000378:metabolism*; D013739:Testosterone / Q000378:metabolism
D008565:Membrane Proteins; D011944:Receptors, Androgen; D013739:Testosterone