Antagonism of estrogenic effects on feeding behavior by central implants of anisomycin

The following experiment determined whether the estrogenic suppression of food intake is dependent upon changes in protein synthesis within neurons of the paraventricular nucleus of the hypothalamus (PVN). Ovariectomized rats were treated centrally with anisomycin-filled or empty (control) cannulae in the PVN. Females were injected with either 2.0 micrograms of estradiol benzoate (EB) or the oil vehicle and the inner cannulae were removed 2 h later. EB injections significantly lowered food and water intake in the central control group but not in animals given PVN implants of anisomycin. Body weight gain decreased for all females. EB induced comparable levels of female sexual behavior in both groups, demonstrating that anisomycin implants did not affect the ability of estradiol to stimulate lordosis. These findings indicate that the effects of estradiol on food intake require the activation of protein synthesis in estrogen-sensitive PVN neurons.