31P NMR study of phosphorus containing metabolites in the uterus of hamster: changes during the estrous cycle and the effect of hormonal manipulation.

Changes in the concentrations of phosphorus containing metabolites were monitored by 31P NMR in the uteri of hamsters during the estrous cycle. Concentrations of phosphocreatine (PCr) and ATP were significantly increased in estrus animals compared to diestrus animals. Concentrations of these metabolites were also increased in immature female hamsters and ovariectomized (OVX) adult hamsters treated with estradiol indicating that estradiol was responsible for this effect. However, the steroid hormones progesterone and testosterone did not increase the concentrations of the phosphorus containing metabolites. Further, immature female hamsters also following treatment with estradiol showed an initial decline in phosphomonoester (PME), PCr, ATP and inorganic phosphate but by 24 h of treatment the concentrations returned to control levels. The NMR study also revealed that the intracellular pH of the hamster uterus was around 7.4 all through the estrous cycle.