Fig. 2.

Effects of KNDy neuron ablation on serum LH (A) and FSH (B). Rats were ovariectomized and injected with NK₃-SAP or Blank-SAP in the arcuate nucleus on d 0, given E₂ capsules 20–23 d later (shown as d 22), and killed after 11 d of E₂. Serum LH and FSH were markedly increased by OVX and reduced by E₂ treatment in Blank-SAP animals. In contrast, serum LH after OVX was not significantly different from intact values in NK₃-SAP rats, and the rise in FSH was attenuated (mean ± sem, n = 6–11 rats/group for both A and B). Serum LH and FSH were significantly lower in KNDy-ablated rats than Blank-SAP controls in both OVX and OVX + E₂-treated groups. #, Significantly different, NK₃-SAP vs. Blank-SAP, P ≤ 0.05; +, significantly different from intact values on d 0, P ≤ 0.01; *, significantly different after E₂ (vs. OVX), P ≤ 0.05.