Soybean isoflavones alter parvalbumin in hippocampus of mid-aged normal female, ovariectomized female, and normal male rats.
OBJECTIVE
To investigate the long-term effect of soybean isoflavones on changes in parvalbumin (PV) immunoreactivity in the hippocampus in normal female, ovariectomized (OVX) female and normal male rats.


METHODS
Ten-month-old rats were assigned to one of 9 groups (n = 7 in each group) based on body weight using a randomized complete-block design. The groups were: control diet-treated females, OVX females, and males; 0.3 g/kg isoflavone-treated females, OVX females, and males; and 1.2 g/kg isoflavone-treated females, OVX females, and males. The PV immunostaining was conducted by using the standard avidin-biotin complex method.


RESULTS
PV immunoreactivity and the number of PV-immunoreactive neurons in all the groups after isoflavone treatment were significantly changed in the hippocampal CA1 region and in the dentate gyrus, but not in the hippocampal CA2/3 region. PV immunoreactivity and the number of PV-immunoreactive neurons in the control diet OVX females were similar to those in the control diet, and were greater than those in the control diet normal females. PV immunoreactivity and the number of PV-immunoreactive neurons in all the isoflavone-treated groups decreased dose-dependently after isoflavone treatment.


CONCLUSIONS
Long-term administration of isoflavones may induce a reduction of PV in interneurons in the hippocampal CA1 region and in the dentate gyrus. The reduction of PV in these regions suggests that the long-term administration of isoflavones may cause a change in calcium homeostasis in the hippocampal CA1 region and in the dentate gyrus.
Hwang
In-koo
IK
Department of Anatomy, College of Medicine, Hallym University, Chunchon, Korea.
Lee
Yoon-bok
YB
Yoo
Ki-yeon
KY
Kang
Tae-cheon
TC
Lim
Soon-sung
SS
Kim
Sang-moo
SM
Sohn
Heon-soo
HS
Kim
Woo-jung
WJ
Shin
Hyun-kyung
HK
Won
Moo-ho
MH
D000818:Animals; D018891:Dentate Gyrus / Q000378:metabolism; D005260:Female; D019833:Genistein / Q000494:pharmacology; D006624:Hippocampus / Q000378:metabolism*; D007529:Isoflavones / Q000302:isolation & purification / Q000494:pharmacology*; D008297:Male; D009474:Neurons / Q000378:metabolism; D010052:Ovariectomy; D010320:Parvalbumins / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013025:Glycine max / Q000737:chemistry
D007529:Isoflavones; D010320:Parvalbumins; C004742:daidzein; C086566:glycitein; D019833:Genistein