THE EFFECT OF CORTICOTROPHIN ON THE RAT UTERINE WEIGHT RESPONSE TO HUMAN CHORIONIC GONADOTROPHIN

Abstract

ABSTRACT The activity of human chorionic gonadotrophin (HCG) in the mouse uterus assay is augmented by the daily injection of corticotrophin (ACTH). This phenomenon has been further investigated in the rat. Synthetic ACTH (75μg) and dehydroepiandrosterone (1.0 mg) augmented responses to 0.1 IU, 0.2 IU and 0.4 IU HCG in the rat uterus assay. The basal uterine weight was also elevated by the treatment. This effect could not be demonstrated in castrated or hypophysectomised animals, and in the latter the response to HCG was not augmented. Cortisone and corticosterone did not affect HCG assay. Cortisone administration did not suppress the augmenting effect of either carbon tetrachloride or urine extract administration on HCG activity. Mean uterine weights from bilaterally adrenalectomised rats were significantly higher than those from intact or sham operated animals. The results are discussed with reference to the augmentation of HCG activity produced by non-specific stressful procedures.