Figure 1.

In vivo and in vitro expression patterns of rat pituitary Gnrhr. (A) Female and male developmental profiles of Gnrhr expression in vivo. Notice the differences in the peak of Gnrhr expression in females and males, as indicated by vertical dotted lines and a horizontal arrow. (B) Gonadotropin-releasing hormone (GnRH)-induced Gnrhr expression in 2-day-old static cultures of anterior pituitary cells from 7-week-old females. Cells were cultured in the absence or in continuous presence of 10 nM GnRH. Notice that desensitization of GnRH-induced Gnrhr expression does not affect basal expression. (C) The amplitude of GnRH-induced (10 nM continuously for 6 h) Gnrhr expression in female and male pituitary static cultures obtained from animals of different age is sex specific, in contrast to comparable levels of expression of this gene in both sexes in vivo (A). (D) GnRH-induced Gnrhr expression in perifused pituitary cells from rat females. Cells were stimulated with 1, 10, or 100 nM GnRH for 1 × 5 min/hour, 2 × 5 min/hour, and 3 × 5 min/hour during 6 h. Notice that 1 nM GnRH was sufficient to induce maximum in response. This figure is derived from data published in Ref. (11, 16, 20); no permission is required from the copyright holder.