Maintenance of normal pituitary weight and cytology in the spayed rat following estradiol implants in the arcuate nucleus


  • Supported by grant NSF G-14580 from the National Science Foundation.


Estradiol contained within the lumen of 30 gauge hypodermic tubing was implanted into the arcuate nucleus, mammillary bodies, or anterior lobe of the pituitary, either at the time of spaying or 11 days or 60 days after castration. The normal pituitary weightand cytological characteristics of the gonadotrophs were maintained only when estradiolwas implanted in the arcuate nucleus after spaying. Blank tubing implants in all the previously mentioned locations or estradiol implants in the mammillary bodies or anteriorpituitary were completely ineffective in inhibiting the typical sequence of castration cell formation which occurs in the pituitary of the spayed rat.