Phosphomonoesterases and Histamine in the Uterus of the Ewe During Early Pregnancy

Abstract

An attempt was made to assess whether histamine is involved in the regulation of sheep uterine endometrial acid and alkaline phosphatases during early pregnancy. Interacting effects of progesterone and oestradiol on the endometrial enzymes and the behaviour of the phosphatases in the caruncles during early pregnancy were also examined.Histamine occurred in greater concentration in .the intercotyledonary endometrium than in the caruncles during early pregnancy and increased in both tissues between days 14 and 22. The concentration of the monoamine fell on day 31 of pregnancy and only low levels in the tissues were recorded on day 44. The subcutaneous administration of the potent histamine-releasing agent, compound 48/80, or the injection of histamine directly into the uterine lumen of ovariectomized ewes treated with combinations of progesterone and oestradiol benzoate, did not significantly alter the phosphatase activity of the endometrial tissue.Progesterone stimulated the acid and alkaline phosphatases in the intercotyledonary endometrium and maintained their activities at high levels for 21 days when administered at a dose rate of 10 mg/day. Oestradiol benzoate slightly decreased endometrial phosphatase activities when injected into ovariectomized ewes and limited the response of the enzymes to progesterone.. r Alkaline phosphatase activity in the caruncles increased between days 0 and 8 of pregnancy and fell on day 14. Only low levels of activity were found in the caruncles on days 22, 31, and 44 of pregnancy. Acid phosphatase maintained a constant level of activity in the caruncles throughout early pregnancy and was not influenced by the increase in histamine concentration between days 14 and 22.The results suggest the participation of factors other than histamine in the regulation of endometrial phosphatases during early pregnancy in the ewe. Progesterone and oestradiol may be involved to some extent but are not solely responsible for the control of the enzymes.

Comparison of Histoenzymological Alterations in the Contralateral Ovary of Nulliparous and Parous Females of the Bat <i>Taphozous melanopogon melanopogon</i> Temmnick (Microchiroptera, Mammalia) Displaying Absolute Dextral Dominance of the Genital Tract

“…1962). Further, several phos phatases are established to be estrogen/progesteronedependent [Murdoch andWhite. 1968.…”

A Quantitative Study of Some Lysosomal Enzymes in the Bovine Endometrium During Early Pregnancy

“…lb). Murdoch (1972b) was able to induce increases in endometrial phosphatase by progesterone treatment of ewes, but he did not consider the hormone to be solely responsible for the enzyme control. Our results provide evidence that, in addition to the effect of altered levels of circulating hormones in pregnancy, the presence of the conceptus itself has a local effect on some biochemical para¬ meters of the endometrium.…”

“…The lower levels of alkaline phosphatase and DNA in the horn containing the embryo at this stage of pregnancy may be artifacts since they were expressed in terms of protein, which itself showed a significant increase in the pregnant horn at that time. As Murdoch (1972b) suggested for the ewe, it seems that the bovine endometrium needs to be primed with progesterone, but there also appears to be a local effect of the conceptus which is transitory for acid phos¬ phatase and prolonged for the RNA:DNA ratio. Studies on steroid synthesis by pig blastocysts (Perry et al, 1973) indicate one possible means by which this local endometrial response may be effected.…”

Acid and Alkaline Phosphatases in Histologically Defined Areas of the Sheep Uterus and Placenta: Histochemical and Microfluorometric Analyses

“…When assayed flu oro metrically, ACP activity in the maternal caruncles remained unchanged between days 10 and 145 of gestation; similarly, Hafez and White (1968) and Murdoch (1972) found a constant activity during the first 6 weeks of gestation. ACP activity in the uterine glands decreased during pregnancy, but in the luminal epithelium maximum activity was recorded on days 15-25 and day 80.…”

“…All spectrophotometric (Hafez and White 1968;Murdoch 1970aMurdoch , 1970b and histochemical (Boshier 1969;Murdoch 1972) studies of ACP and ALP in the uterus of pregnant sheep have been confilled to the first few weeks of gestation. Histochemical findings have been reported mostly for the epithelial and caruncular tissues and other uterine tissues have not received much attention.…”