Objective:To observe the imprinting effects of prenatal overexposure to glucocorticoids on 11?-hydroxysteroid dehydrogenase type 1(11?-HSD1) expression in the rat offspring liver. Methods: Pregnancy was determined by examining vaginal smear. Eight pregnant rats were divided into dexamethasone(DEX) group and normal saline(NS) group at random with each group containing 4 rats.DEX group was given subcutaneous injection of DEX [0.05 mg/(kg?d)] and NS group was given injection of NS.Western blot was adopted to determine 11?-HSD1 protein in the liver of the offspring at the age of 4 months;RT-PCR was used to determine 11?-HSD1 mRNA and hepatic phosphoenolpyruvate carboxykinase(PEPCK) mRNA;and glucose oxidase method was used to measure the blood glucose concentration. Results: Western blot and RT-PCR showed that prenatal overexposure to DEX increased the expression of 11?-HSD1 protein and mRNA in the liver of the female offsprings at 4 months old, but not in male offsprings.Prenatal overexposure to DEX also increased the expression of PEPCK mRNA and blood glucose level in the female offsprings at 4 months old.Conclusion:Our study suggests that prenatal overexposure to glucocorticoids throughout gestation can imprint the expression of 11?-HSD1 in rat offsprings liver, which may lead to the PEPCK overexpression and blood glucose elevation.Development of diabetes may be induced in individuals overexposed to glucocorticoids during fetal period.

The osmotic pressure of ammonium sulfate solutions has been measured by the well-established freezing point osmometry in dilute solutions and we recently reported air humidity osmometry in a much wider range of concentration. Air humidity osmometry cross-validated the theoretical calculations of osmotic pressure based on the Pitzer model at high concentrations by two one-sided test (TOST) of equivalence with multiple testing corrections, where no other experimental method could serve as a reference for comparison. Although more strict equivalence criteria were established between the measurements of freezing point osmometry and the calculations based on the Pitzer model at low concentration, air humidity osmometry is the only currently available osmometry applicable to high concentration, serves as an economic addition to standard osmometry.