Age-dependent participation of the adenohypophysis and adrenal cortex in the estrogenic response of the quail oviduct.

Abstract

The purpose of this work was to study the role played by the pituitary in the overall estrogenic response of the quail oviduct during the first 30 days of life. The oviduct response (weight, soluble protein, and DNA content) was measured in castrated and castrated-hypophysectomized quails 24 h after a single im dose of 0.1 or 1 mg estradiol benzoate (EB)/kg BW. The effect of ACTH (0.5 mg/kg) and corticosterone (1 mg/kg) alone or in combination with EB has been investigated as well. The monitored parameters show different patterns as a function of age whether the castrated quails were injected with 0.1 mg or 1 mg EB/kg. These patterns are linear in quails treated with low doses of EB and nonlinear in animals treated with high doses of EB. In this latter group, the oviduct responses to EB, regardless of parameter measured, are constant from days 8-18, increase progressively from days 18-22, and are constant again from days 22-30. Hypophysectomy, ACTH administration, or corticosterone administration does not...