The Composition of Rat Uterine Luminal Fluid

The chemical composition of uterine fluid collected from ewes cannulated by three different procedures was studied.Sodium and chloride were the major inorganic ions present. Smaller amounts of potassium, magnesium, calcium, ammonium, bicarbonate, and phosphate ions were also found. Orcinol-reactive carbohydrate was present in high concentration but only 1--4 % could be accounted for as the reducing sugar, glucose. Approximately 5 mM lactate was present in the uterine secretions.Protein concentration varied from 1 to 3 g/loo ml and some differences existed between uterine fluid and blood serum both in electrophoretic mobility and relative concentration of the various protein components. Uterine fluid also differed in amino acid composition from blood serum and the results suggest that uterine fluid is, at least in part, a true secretion and not merely a blood transudate.Differences in chemical composition between stages of the oestrous cycle were small and only minor differences were found between fluid collected from the uterine horn and that collected from the body of the uterus. By contrast the composition of fluid collected from ewes with a cannula inserted through the cervical canal differed considerably from that of fluid collected by the other two methods of cannulation and the former method may give a less reliable estimate of the true uterine environment.

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

The Uterus of the Ewe II. Chemical Analysis of Uterine Fluid Collected by Cannulation

Rg¹

1973

“…Although there were no significant differences in the concentration of protein between stages of the cycle in the present study, other workers have found cyclical changes in the level of protein in fluids from other parts of the female genital tract. Thus Ringler (1961) found that oestrogen elevated the levels of protein in uterine fluid from the rat, and Wallace, Stone, and White (1965) found a greater protein concentration in rinsings from the rat uterus during pro-oestrus and oestrus.…”

Section: C) Statistical Analysesmentioning

confidence: 99%

“…Howard and de Feo (1959) noted a similar elevation in the concentration of potassium in the rat uterus and concluded that a true secretion occurred. Ringler (1961), also studying the uterine fluid of the rat, found levels of potassium 10 times greater than found in blood and concluded that this fluid was at least supplemented by a true secretion. The lowest concentrations of the electrolytes in the normal ewes occurred during metoestrus, when endogenous levels of oestrogen can be expected to be waning.…”

Section: C) Statistical Analysesmentioning

confidence: 99%

The Fallopian Tube of the Sheep III. The Chemical Composition of the Fluid from the Fallopian Tube

Restall¹,

Wales²

1966

SummaryThe chemical composition of fluid from the fallopian tube of the ewe was studied in four cycling ewes and in four groups of four ovariectomized ewes receiving oestrogen and progesterone in factorial combination. Both the major electrolytes and some organic constituents in the fluids were examined.Sodium was found to be the main cation present and chloride the main anion. Smaller amounts of potassium, magnesium, calcium, phosphate, and bicarbonate were also present. Fluid from the normal ewes contained less magnesium than that from the spayed ewes. Within the spayed ewes, oestrogen caused an increase in potassium and bicarbonate and a decrease in magnesium. The concentration of sodium, potassium, chloride, and bicarbonate were lowest during metoestrus. The concentration of magnesium, on the other hand, was lowest during oestrus and highest during dioestrus.Total phosphorus, acid-insoluble phosphorus, total orcinol-reactive carbohydrate, protein, and lactic acid in the fluids was also assayed. All these constituents showed considerable variation between samples. However, no changes during the oestrous cycle were evident. Glucose could not be detected in any of the fluids.Within the spayed ewes, oestrogen, administered alone, decreased the con· centration of protein but when given in combination with progesterone, caused the opposite effect. Carbohydrate and lactate increased during the second cycle of treatment in those spayed ewes receiving oestrogen. Acid-insoluble phosphorus was found to increase in the second cycle of treatment in all animals.

“…Whilst the role of K + during embryonic development has not been studied extensively, this ion is known to affect the metabolism of energy substrates by cells such as spermatozoa (Wallace and Wales 1964). Thus the high concentration of K + found in the uterine fluid of mice (Edirisinghe and Wales 1980) and other animals (Olds and VanDemark 1957;Howard and De Feo 1959;Ringler 1961;Heap 1962;Wales 1973) may have some significance in the control of the metabolism of the differentiating embryo.…”

Section: Introdnctionmentioning

confidence: 99%

Influence of Environmental Factors on the Metabolism of Glucose by Preimplantation Mouse Embryos in vitro

Edirisinghe¹,

Wales²

1985

The metabolism of glucose by late pre implantation mouse embryos was studied in a variety of media whose composition had been changed to reflect the environmental conditions in the uterus more closely than do standard culture media. The effects of combinations of energy substrates, the presence or absence of amino acids and the level of potassium in the medium were investigated.The use of energy substrates for in vitro culture at levels present in the uterine environment resulted in rates of synthesis and degradation of glycogen pools similar to those obtained using standard in vitro culture conditions but elevated incorporation into non-glycogen macromolecules. Amino acids influenced the metabolism of glucose by limiting the entry of glucose carbon into the non-glycogen macromolecular pool and directing more glucose into the synthesis of acid-soluble glycogen.Increasing the K + concentration to 60 mM in the culture medium caused a small but significant increase in the number of eight-cell embryos degenerating during culture for 24 h but the metabolism of glucose was unaffected over this time. At the time of morula transformation to the blastocyst this level of potassium ions suppressed glycogen synthesis by 50% over 5 h but did not affect its turnover during chase culture.It is concluded that factors other than those studied here contribute to the maintenance of the low glycogen levels found in uterine embryos. IntrodnctionEarlier work (Ozias and Stern 1973;Ozias and Weitlauf 1971;Snyder et al. 1971;Edirisinghe et al. 1984aEdirisinghe et al. , 1984b indicates that the uterine environment influences the metabolism of late preimplantation mouse embryos and in particular the utilization of glycogen stores. This environment is more complex than, and differs in the range and concentration of components from, the standard chemically defined media normally used for in vitro culture (Hamner 1971;Wales 1973;Beier 1974; Edirisinghe and Wales 1985). Changes in the environment may well be important in modifying the metabolism of glucose by embryos and be responsible for the differences in the turnover of glycogen in vivo as compared to its utilization in vitro.The possible control of glycogen metabolism by the level of exogenous energy substrate has been studied using different concentrations of the major energy substrates, glucose, lactate and pyruvate (Pike and Wales 1982). It is clear from this study that embryos, especially at the late preimplantation stages, have the ability to synthesize large amounts of glycogen and that the presence of the alternative energy substrates, lactate and pyruvate during culture influences the synthesis of glycogen, particularly when the medium contains a low concentration of glucose. Recently, the levels of lactate, pyruvate and glucose in the uterine fluid of mice have been measured and found 0004-9417/85/040411 $02.00