Advanced increase in plasma luteinizing hormone (LH) levels in female rats
treated with a kappa-opioid receptor antagonist, nor-binaltorphimine
(nor-BNI), or a neurokinin 3 receptor agonist, senktide. Plasma LH profiles
in representative animals are shown in panel A. Arrowheads indicate peaks of
LH pulses identified by the PULSAR computer program. Mean LH concentrations
and the frequency and amplitude of LH pulses are shown in panel B. The
numbers in each column of mean LH concentrations and the frequency of LH
pulses indicate the numbers of animals used, and the numbers in each column
of the amplitude of LH pulses indicate the number of animals showing LH
pulses. Values are means ± SEM. Values with different letters are
significantly different (P < 0.05, one-way ANOVA followed by Tukey’s HSD
test) from each other. Statistical differences in amplitude of LH pulses
were not determined because only one vehicle-treated animal showed an LH
pulse.