|Chamber||applicator/ 350 mm x 470 mm x 455 mm|
|Setup||6 virgin rats and pregnant rats were placed in a semicylindrical acrylic plastic holder (5 mm thick x 60 mm in diameter, 170 mm long)|
|Additional info||Equal number of virgin and pregnant rats served as control, in which identical treatment as the exposed rats was observed except that the microwave generator was switched off. The environment during exposure was maintained at 21 to 23°C and 50 to 60% humidity.|
Skin temperature in virgin and pregnant rats increased immediately after exposure. Although splenic activity of natural killer cells and any of the subset populations not differ in virgin rats with or without irradiation, pregnant rats exposed to microwaves showed a significant reduction of splenic activity of natural killer cells. Furthermore corticosterone and ACTH increased, and estradiol decreased in exposed virgin and pregnant animals. In contrast, microwaves produced significant increases in beta-endorphin and progesterone only in pregnant animals.
These data in pregnant rats suggest that with irradiation pregnancy induces immunosuppression, which could result in successful maintainance of pregnancy. This increase of adaptability to heat stress may be mediated by activation of placental progesterone and placental or pituitary beta-endorphin.