Hormonal protection of gender-related peculiarities of testosterone metabolism in the brain of prenatally stressed rats.
OBJECTIVE
Prenatal stress results in demasculinization and feminization of sexual behavior in adult male rats. Earlier the preventive effect of testosterone replacement of an androgen deficiency in male fetuses during exposure to stress has been demonstrated. Nevertheless the neuroendocrine mechanisms underlying hormonal protection of the brain sexual differentiation are not clear.


METHODS
Time-mated rats were undergone to 1 h strict immobilization during days 15 to 21 of gestation. Another group of stressed dams was injected with testosterone propionate on the 17th, 19th and 21st gestational days subcutaneously (5 mg/kg b.w.) 30 min prior to restraining. Aromatase and 5alpha-reductase activities were determined in the preoptic area and medial basal hypothalamus of 10-day old offspring.


RESULTS
Aromatase activity in the preoptic area declined in affected with prenatal stress males and reached the normal female level. It completely restored in prenatally stressed males under influence of prenatal testosterone replacement. 5alpha-reductase activity decreased in the preoptic area of prenatally stressed females. In those pretreated with testosterone propionate, 5alpha-reductase activity was significantly elevated above normal level.


CONCLUSIONS
The data obtained demonstrate a preservation of aromatase activity in the preoptic area of males resulted from testosterone replacement. Presumably testosterone exerts its protective effect on the male sexual behavior by prevention of neurochemical feminization of the brain preoptic area and, perhaps, due to some other mechanisms.
Reznikov
Alexander G
AG
Department of Endocrinology of Reproduction and Adaptation, Institute of Endocrinology and Metabolism, Kiev, Ukraine. dccie@mail.kar.net
Tarasenko
Larisa V
LV
D000818:Animals; D001141:Aromatase / Q000378:metabolism*; D042944:Cholestenone 5 alpha-Reductase / Q000378:metabolism; D005260:Female; D007033:Hypothalamus, Middle / Q000196:embryology / Q000201:enzymology*; D007103:Immobilization; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011301:Preoptic Area / Q000196:embryology / Q000201:enzymology*; D051381:Rats; D017208:Rats, Wistar; D012727:Sex Characteristics; D013315:Stress, Psychological / Q000201:enzymology*; D013739:Testosterone / Q000378:metabolism*
D013739:Testosterone; D001141:Aromatase; D042944:Cholestenone 5 alpha-Reductase