Female rat pups were subcutaneously injected with oil or 2.5 mg of testosterone propionate on the day of birth. On PND 60, rats were either ovariectomized (OVX) or sham-operated and left intact. Six days later, these rats were fitted with jugular catheters. The following day, blood samples were collected every 30 minutes for 3 hours from 1200h to 2100h. Serum LH levels were determined by RIA. Both mean LH levels (ng/ml) and mean pulse amplitude of LH was significantly increased (*p<0.001) by ovariectomy in control-treated females as compared to the SHAM control group (SHAM, n=3; OVX, n=5). Ovariectomy did not alter LH levels or pulse amplitude in the T-treated (n=5 for both groups) females.