Uteroglobin in the rabbit

Summary

Rabbit uterine uteroglobin (UGL) was studied by electrophoretic and immunological methods following normal copulation, after ovariectomy and progesterone treatment, 17β-oestradiol and combined progesterone treatment, 17β-oestradiol treatment alone and after HCG-induced pseudopregnancy. Electrophoretic studies show the amount of ULG in uterine secretions, the immunological investigations indicate the intracellular localization of ULG and the distribution of ULG-positive cells in the endometrium.

No obvious differences were found between the uteri 7 days after injection with chorion-gonadotropin and those 7 days following normal copulation. No differences could be demonstrated between the uteri of animals 35 days following ovariectomy and subsequent progesterone treatment on Days 31–33 and those of normal 7 d. post coitum (p.c.) animals. Uteri from animals treated with progesterone on Days 2–5 p.c. contained more ULG-positive cells than controls. 17β-oestradiol treatment with and without subsequent progesterone treatment resulted, in both gravid and ovariectomized animals, in the formation of a tall columnar endometrial epithelium. Treatment with 17β-oestradiol on Days 1 and 2 p.c. led to a decrease in the number of UGL-positive cells at 7 days p.c. Even after ovariectomy with 17β-oestradiol substitution, UGL-positive cells were still present in the endometrium. However a secretion of any magnitude could not be detected. The importance of differentiation between synthesis and secretion (= release) as distinct phases of the glandular response is especially emphasised by the latter findings.