AIM: We studied the estrogen receptor (ER) and progesterone receptor (PR) isoforms expression in gastric antrum and corpus of female gerbils and their regulation by estradiol (E2) and progesterone (P4). METHODS: Ovariectomized adult female gerbils were subcutaneously treated with E2, and E2 + P4. Uteri and stomachs were removed, the latter were cut along the greater curvature, and antrum and corpus were excised. Proteins were immunoblotted using antibodies that recognize ER-alpha, ER-beta, and PR-A and PR-B receptor isoforms. Tissues from rats treated in the same way were used as controls. RESULTS: Specific bands were detected for ER-alpha (68 KDa), and PR isoforms (85 and 120 KDa for PR-A and PR-B isoforms, respectively) in uteri, gastric antrum and corpus. We could not detect ER-beta isoform. PR isoforms were not regulated by E2 or P4 in uterus and gastric tissues of gerbils. ER-alpha isoform content was significantly down-regulated by E2 in the corpus, but not affected by hormones in uterus and gastric antrum. CONCLUSION: The presence of ER-alpha and PR isoforms in gerbils stomach suggests that E2 and P4 actions in this organ are in part mediated by their nuclear receptors. AIM: We studied the estrogen receptor (ER) and progesterone receptor (PR) isoforms expression in gastric antrum and corpus of female gerbils and their regulation by estradiol (E2) and progesterone (P4). METHODS: Ovariectomized adult female gerbils were subcutaneously treated with E2, and E2 + P4. Uteri and stomachs were removed, the latter were cut along the greater curvature, and antrum and corpus were excised. Proteins were immunoblotted using antibodies that recognize ER-alpha, ER-beta, and PR-A and PR - B receptor isoforms. Tissues from rats treated in the same way were used as controls. RESULTS: Specific bands were detected for ER-alpha (68 KDa), and PR isoforms (85 and 120 KDa for PR-A and PR-B isoforms , respectively) in uteri, gastric antrum and corpus. We could not detect ER-beta isoform. PR isoforms were not regulated by E2 or P4 in uterus and gastric tissues of gerbils. ER-alpha isoform content was significantly down-regulated by E2 in the corpus, but not affected by hormones i CONCLUSION: The presence of ER-alpha and PR isoforms in gerbils stomach suggests that E2 and P4 actions in this organ are part-mediated by their nuclear receptors.