Extracellular Signal-Regulated Kinase (ERK) Activation and Mitogen-Activated Protein Kinase Phosphatase 1 Induction by Pulsatile Gonadotropin-Releasing Hormone in Pituitary Gonadotrophs
Figure 3
Induction of MKP1 by high frequency of GnRH pulse stimulation. (a) LbT2 cells were stimulated with vehicle (control) or pulsatile GnRH (10 nM, 5 min pulse flow per each pulse) at a frequency of one pulse every 30 min (high) or one pulse every 2 h (low). After 16 h stimulation, MKP1 protein expression was determined by Western blotting. MKP1 expression was increased predominantly following high rather than low-frequency GnRH pulse stimulation. (b) Time course of MKP1 expression following high-frequency GnRH pulse. Under the high frequency GnRH pulse stimulation, MKP1 protein expression was observed clearly at 2 h after the start of pulse stimulation (four GnRH pulses). ** versus control [26].
