2-hydrazino-1-methylpyridine and Prostatic-Hyperplasia

A derivatization reagent, 2-hydrazino-1-methylpyridine, was developed for the liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) of oxosteroids. The reagent quantitatively reacted with oxosteroids at 60 degrees C within 1h and the resulting derivatives of the mono-oxosteroids provided a 70-1600-fold higher sensitivity compared to intact steroids. However, HMP was unsuitable for di-oxosteroids, such as androstenedione and progesterone. The developed derivatization procedure was applied to the LC-ESI-MS analysis of 5alpha-dihydrotestosterone in human prostate, and allowed the reproducible quantification of nanogram/gram level of the androgen with a 10-mg sample.

Topics: Androgens; Chromatography, Liquid; Dihydrotestosterone; Humans; Hydrazines; Ketosteroids; Male; Prostate; Prostatic Hyperplasia; Pyridines; Pyridinium Compounds; Reproducibility of Results; Sensitivity and Specificity; Spectrometry, Mass, Electrospray Ionization; Testosterone

A practical liquid chromatography-tandem mass spectrometric (LC-MS-MS) method for the determination of prostatic 5alpha-dihydrotestosterone (DHT) and testosterone (T) has been developed. The prostatic androgens were extracted with MeOH-H2O (3:7, v/v), purified with an Oasis HLB cartridge, derivatized with the permanently charged reagent 2-hydrazino-1-methylpyridine (HMP), and subjected to LC-MS-MS analysis using electrospray ionization (ESI) operated in the positive ion mode. The derivatization with HMP was very effective at increasing the detectability using the positive-ESI-MS. The method allowed the reproducible and accurate quantification of ng g(-1) tissue levels of prostatic androgens in 10 mg of tissue. That is, the intra- and inter-assay coefficients of variation were below 8.1 and 9.3%, respectively, and the analytical recoveries of the androgens were quantitative. The limits of quantitation for DHT and T were both 1.0 ng g(-1) tissue. The developed method was used to determine DHT and T in the prostates of patients with benign prostatic hyperplasia and prostate cancer, and satisfactory results were obtained.

Topics: Chromatography, Liquid; Dihydrotestosterone; Humans; Hydrazines; Male; Molecular Structure; Prostatic Hyperplasia; Pyridines; Sensitivity and Specificity; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry; Testosterone; Time Factors