The Effects of Sex Steroid Hormones on the Pigment Accumulation in the Shell Gland of Japanese Quail

Abstract

Effects of sex steroid hormones on the accumulation of the superficial pigment of the eggshell in the quail shell gland were investigated. In Experiment 1, 10 or 20 mg/100 g BW of aminoglutethimide (AG) was injected s.c. into laying quail hens 10 h before the expected ovulation. Thirty percent of the hens that received 10 mg/100 g BW and 87% of the hens that received 20 mg/100 g BW failed to ovulate. They had significantly (P < .01) lower concentrations of preovulatory plasma progesterone (P) than the control hens and showed significantly (P < .05) low concentrations of plasma estradiol-17β (E) and small amounts of the pigment in their shell glands after oviposition of the preceding egg. In Experiment 2, AG (20 mg/100 g BW) was administered s.c. to quail hens 10 h before the expected ovulation, followed by the administration of P (.05, .1, or .2 mg/100 g BW), E (.1, .2, or 1.0 mg/100 g BW), or testosterone (T) (.5 mg/100 g BW). Significant increases in the accumulated pigment 18 h after oviposition of the preceding egg were found when P was injected. However, administration of E and T had no influence on pigment accumulation. These results suggested that P might affect the accumulation of pigment in the quail shell gland.