Histological and biochemical studies of the uterus of ovariectomized gilts during the first two months of pregnancy after different hormone substitutions. 4. Effect of the conceptus on the activities of alkaline and acid phosphatase and the concentration of glycogen in the uterus during different supplies of progesterone and norgestrel

Forty-five ovariectomised gilts in early gravidity received injections of progesterone doses between 120 mg and 40 mg as well as 250 micrograms/die of oestradiol-benzoate and oral application of 12 mg/die of norgestrel, the latter being administered in addition to the 40 mg dose of progesterone. The animals were killed between the 20th and 24th or on the 35th days of gravidity, before endometrial activities were determined of alkaline and acid phosphatases at various points of the uterus (centre and sides of ampullae and in-between ampullae). Under conditions of sufficient progesterone supply (120 mg/die and 100 mg/die), endometrial activities of both alkaline and acid phosphatases in the centre of ampullae were found to be higher than those in-between them. Activities were lower with inadequate progesterone supply (40 mg/die), and differences between points of sampling were less strongly pronounced for alkaline phosphatase. Endometrial glycogen concentrations in the centre of ampullae were lower than those in-between. Values in response to inadequate progesterone administration were lower than those following sufficient supply. With regard to glycogen concentrations, differences between points of sampling in the myometrium were below those in the endometrium.