Fig 1. Letrozole induced changes in tissue concentrations (pg/g) of estrogens and androgens in the testis, prostate, and liver.

Estrone (A) and estradiol (B) concentrations were decreased in the testis of 16, 20, and 40 week boars compared with vehicle-treated littermates. Estrone (A) and estradiol (B) concentrations in the prostate and liver were not affected by letrozole treatment. Estrone sulfate (C) and estradiol sulfate (D) concentrations were decreased compared with vehicle-treated littermates at week 16 and 20 in all tissues. The aromatase substrates, androstenedione (E) and testosterone (F), were not affected in any tissue by letrozole administration. * P < 0.05, ** P < 0.01.