Gender difference in BK channel expression in amygdala complex of rat brain.
The expression of large-conductance Ca(2+)-activated K(+) (BK) channel protein in amygdala complex was higher in adult (8-10 weeks old) male rats than in female. Castration at 4-6 weeks old significantly reduced BK channel expression in amygdala to the level similar to that in female. Immunocytochemical analyses of pyramidal-like neurons isolated from amygdala revealed that somas with relatively large size were highly immunoreactive to both anti-androgen receptor (AR) and anti-BK channel antibodies, while those with smaller size were not. The double-immunopositive neurons were dominant (60%) among pyramidal-like neurons isolated from amygdala of male rats but rare among those from female. The membrane current sensitive to penitrem A, a BK channel blocker, was the major K(+) current component in large neurons and showed higher current-density than that in smaller ones. These results suggest the gender-dependent cell population expressing BK channels in amygdala complex and its up-regulation by AR stimulation.
Ohno
Akitoshi
A
Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Mizuhoku, Nagoya, Japan.
Ohya
Susumu
S
Yamamura
Hisao
H
Imaizumi
Yuji
Y
D000679:Amygdala / Q000166:cytology / Q000378:metabolism*; D000728:Androgens; D000818:Animals; D005260:Female; D051036:Large-Conductance Calcium-Activated Potassium Channels / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D008297:Male; D009183:Mycotoxins / Q000494:pharmacology; D017966:Pyramidal Cells / Q000378:metabolism; D051381:Rats; D011944:Receptors, Androgen / Q000096:biosynthesis; D012737:Sex Factors; D015854:Up-Regulation
D000728:Androgens; D051036:Large-Conductance Calcium-Activated Potassium Channels; D009183:Mycotoxins; D011944:Receptors, Androgen; C003626:tremortin