Fig. 2.
GnrhrE90K affects circulating concentrations of gonadotropins. Blood levels of LH and FSH were measured by RIA. A and B, Males. Serum levels for both LH (A) and FSH (B) were reduced in E90K homozygotes as compared with E90K heterozygotes, which are phenotypically identical to wild type. Serum levels of FSH and LH were mostly below the lower limit of detection for L117P homozygotes. C and D, Females. The serum level of LH (C) was not different between E90K heterozygotes and homozygotes. The serum level of FSH (D) was reduced in E90K homozygotes as compared with E90K heterozygotes, which are phenotypically identical to wild type. Serum levels of FSH and LH were mostly below the lower limit of detection for L117P homozygotes. E, Buserelin challenge. The serum level of LH was determined before and 75 min after buserelin injection. Buserelin increased serum LH levels for both E90K/+ and E90K/E90K mice; however, LH release was much greater for E90K/+. Significant differences are denoted by the lowercase letters above each bar (A–D) or by an asterisk (E). Equivalent means have the same letter; different letters indicate statistically significant differences (P < 0.05). Error bars represent sem.