Upper panel, Mean (± sem) CSF AgRP (RIA) levels shown on the left axis in 11 OVX monkeys before (solid bars) and after 6 wk of E2 replacement (hatched bars). CSF AgRP (RIA) decreased significantly after E2 (*, P = 0.016). The corresponding POMC to AgRP (RIA) ratio is shown on the right axis and increased after E2 (*, P = 0.01). Lower panel, Mean (±sem) CSF AgRP (RIA) levels in four OVX monkeys studied before (solid bar) and after 1 and 6 wk of E2 replacement (hatched bars). CSF AgRP (RIA) levels were significantly lower after 6 wk of E2 (*, P < 0.05) but not after 1 wk of E2.