Time course of the LH level in serum of castrated rats after
administration of the test substances. (a) s.c.
administration of the unmodified Spiegelmer NOX 1255
(●, blue). (b) i.v. administration
of PEGylated Spiegelmer NOX 1257 (●, blue). The
control groups received Cetrorelix (▴, green) and vehicle
(■, red). A group of intact animals receiving vehicle (⋄,
black) provided the baseline level of LH. The blood samples were
analyzed by RIA. Each data point represents the average value of all
animals per group. d1 represents the LH concentration before
castration. The suppression observed in the experiment shown in
a was not statistically significant; however, the
suppression found in the experiment shown in b showed a
clear statistical significance. One animal that received NOX 1257
showed a delayed response, causing the slight increase of the curve at
time point 3 h.