Modulation of food intake by hypothalamic implants of estradiol benzoate, estrone, estriol and CI-628 in female rats

Ovariectomised rats were implanted unilaterally with cannulae aimed at the ventromedial nucleus-arcuate region of the hypothalamus. Crystalline implants of estradiol benzoate and of the antiestrogenic compound CI-628 over a 72-hour stimulation period caused significantly greater food intake reductions than did implants of cholesterol. More dorsal and lateral placements were generally ineffective in reducing food intake. Implants of estrone and estriol produced equivalent reductions in food intake and body weight to those produced by estradiol benzoate. The possible molecular mode of action is discussed.