Determination of progesterone in human peripheral blood using gas-liquid chromatography with electron capture detection

Sexual Dimorphism of the Mouse Plasma Metabolome Is Associated with Phenotypes of 30 Gene Knockout Lines

Although metabolic alterations are observed in many monogenic and complex genetic disorders, the impact of most mammalian genes on cellular metabolism remains unknown. Understanding the effect of mouse gene dysfunction on metabolism can inform the functions of their human orthologues. We investigated the effect of loss-of-function mutations in 30 unique gene knockout (KO) lines on plasma metabolites, including genes coding for structural proteins (11 of 30), metabolic pathway enzymes (12 of 30) and protein kinases (7 of 30). Steroids, bile acids, oxylipins, primary metabolites, biogenic amines and complex lipids were analyzed with dedicated mass spectrometry platforms, yielding 827 identified metabolites in male and female KO mice and wildtype (WT) controls. Twenty-two percent of 23,698 KO versus WT comparison tests showed significant genotype effects on plasma metabolites. Fifty-six percent of identified metabolites were significantly different between the sexes in WT mice. Many of these metabolites were also found to have sexually dimorphic changes in KO lines. We used plasma metabolites to complement phenotype information exemplified for Dhfr, Idh1, Mfap4, Nek2, Npc2, Phyh and Sra1. The association of plasma metabolites with IMPC phenotypes showed dramatic sexual dimorphism in wildtype mice. We demonstrate how to link metabolomics to genotypes and (disease) phenotypes. Sex must be considered as critical factor in the biological interpretation of gene functions.

LC-MS/MS quantification of progesterone in ovariectomized miniature swine and its application for preliminary pharmacokinetic study of a novel vaginal sustained release system

OBJECTIVE

We here established a simple, fast, robust and sensitive LC-MS/MS method and validated as well for the quantitative analysis of progesterone (PGT) in ovariectomized (OVX) miniature swine plasma. The method was successfully applied to characterize the pharmacokinetics of a progesterone vaginal drug delivery system.

METHODS

Megestrol acetate was utilized as an internal standard (IS). The separation and detection of PGT from endogenous interference was performed successfully by liquid chromatography with gradient elution and mass spectrometry equipped with positive ESI source using MRM mode. The EVA intravaginal rings (IVRs) were manufactured by hot-melt extrusion (HME), afterward were administrated vaginally to OVX minipigs to evaluate PK study.

RESULTS

The calibration curve for swine plasma samples across the concentration ranged between 0.25 ng/mL and 100 ng/mL. The intra- and inter-assay accuracy and precision were lower than ±5% and 5.88%, respectively. Recoveries of PGT and IS were ranging from 114-119% and 96.5-112%, respectively. In vitro study showed that the EVA IVRs release 18 mg/day of PGT continuously over 7 days, and corresponding mean PGT plasma concentration in OVX minipigs (C_AVG) was 4.892 ng/mL.

CONCLUSION

All the study produced reliable results for the measurement of PGT concentration in miniature swine plasma and the method was successfully applied to a PK study for PGT vaginal ring in miniature pigs, which may lay the foundation for further research on the progesterone preparations intended for in assisted reproductive technology.

A competitive dipstick enzyme immunoassay for diagnosis of early pregnancy in bovine

Early pregnancy diagnosis in bovines is one of the important aspects in efficient dairy farm management. In order to develop a competitive enzyme immunoassay (EIA) employing low cost reagents, anti-progesterone antiserum and progesterone-penicillinase enzyme conjugate were prepared. Using this anti-serum and conjugate along with pencillinV-starch-iodine substrate system, the competitive EIA was standardized. In the experiment, danazol, a weak androgen used to extract the progesterone bound to proteins in milk, was included after standardizing the optimum concentration. Incubation period and temperature and pH of the reaction mixture were also optimized. The developed test was validated with milk samples obtained from dairy farm and individual animal owners. Confirmation of the pregnancy was made by per rectum examination of the genital tract around 60 days post-insemination. The user friendly test procedure showed sensitivity and specificity of 83.3% and 87.5%, respectively as compared with residual binding method which was earlier developed in the laboratory with sensitivity and specificity of 100% and 87.5% respectively.

Simple and rapid method for the determination of progesterone in rat plasma by gas-liquid chromatography with electron-capture detection

A method for estimating progesterone in rat plasma using gas-liquid chromatography (GLC) with electron-capture detection is described. By means of a column chromatographic technique for the extraction of progesterone from plasma, it is possible to isolate the steroid in such a specific way that, contrary to previously published methods, no additional chromatographic purification and separation steps are needed prior to the final GLC analysis. As a derivative for electron-capture detection we used the 3,20-di-O-pentafluorobenzyloxime of progesterone. This derivative is superior to those used hitherto with regard to sensitivity and stability. The high overall recovery (mean value, 89.4%) makes this method especially convenient for research work when only little plasma is available, or when the concentration of progesterone is very low.

Androluteoma syndrome of pregnancy

The clinical course of a 26-year-old primigravid woman with a virilizing luteoma of pregnancy is described. It was demonstrated by endocrine studies that the tumor secreted an excessive amount of testosterone. After removal of the luteoma in week 32 of pregnancy, the virilizing symptoms of the mother completely regressed. A normal male infant was delivered in week 39. From 100 luteomas of pregnancy described in the literature, 26 cases have been cited to elicit endocrine virilizing activity. An evaluative synopsis indicates that including the case described in this paper only 13 can be regarded as a clinical, morphologic, and functional entity. This entity should be differentiated from the inhomogeneous group of luteomas as the "androluteoma syndrome of pregnancy." It is characterized by the following major criteria: virilization, beginning with the second trimester of pregnancy; histologic criteria of a luteoma of pregnancy; production of testosterone, leading to excessive plasma levels (exceeding the concentration of androstenedione), and masculinization of female fetuses.

A simple gas-liquid chromatographic method with electron capture detection for the determination of progesterone in the blood of humans and domestic animals

A simple routine method is reported for the determination of progesterone in blood by gas-liquid chromatography. An unlabelled internal standard, testosterone acetate, was added to plasma samples. Following preliminary purification by thin-layer chromatography, progesterone in pregnancy plasma was evaluated as the free steroid with a flame ionization detector. The hormone in the plasma of women during the menstrual cycle and of cycling domestic animals was determined as the 3-enol ester heptafluorobutyrate by electron capture detection. The validity of testosterone acetate as an internal standard was proved by simultaneous processing of [7alpha-3H]progesterone and a [4-14C]testosterone acetate and the determination of the isotope ratio in samples. The results of control experiments and normal values are also presented.

Endocrine control of adrenal progesterone secretion in the ovariectomized rat

In the ovariectomized rat, the adrenal gland secretes progesterone. Adrenocorticotropin treatment elevates concentrations of this steroid in plasma, and inhibitors of adrenocorticotropin or progesterone biosynthesis lower the concentration. Adrenocorticotropin controls progesterone secretion by the adrenal but not by the ovary. Adrenal progesterone and its mode of control may have important influences on reproductive processes.

The luteo-placental shift, the guardian of pre-natal life

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