• Development and Reproduction
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• v.25 no.2
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• pp.75-82
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• 2021

We studied steroid metabolites produced from red-spotted grouper ovarian follicles during maturation. Oocytes with 350-500 ㎛ diameter were in vitro incubated in the presence of [³H] 17α-hydroxyprogesterone as a precursor. Steroid metabolites were extracted from incubated media and oocytes. The extracts were separated and identified using thin layer chromatography, high performance liquid chromatography and gas chromatography-mass spectrometry. The identified metabolites were androstenedione (A₄), testosterone (T) and estrone (E₁). The metabolites of A₄ was dominant in all size of oocytes and it was the highest in 480 ㎛ diameter oocytes. The metabolites of two progestins, 17α,20β-dihydroxy-4-pregnen-3-one and 17α,20α-dihydroxy-4-pregnen-3-one were detected in the oocytes less than 480 ㎛ diameter although they were not identified definitely. In the oocytes of 480 ㎛ diameter, metabolite of progestin was the highest, and germinal vesicle (GV) was still in the middle of cytoplasm. In the oocytes of 500 ㎛ diameter, GV was began to migrate and the major metabolites were A₄ and E₁. The metabolite of E₁ was detected in all size of oocytes and it was higher than that of E₂. These results suggest that oocytes of 480 ㎛ diameter are the transitional stage involving steroidogenic shift to final oocyte maturation and potential function of E₁ during maturation process.

• Mass Spectrometry Letters
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• v.5 no.2
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• pp.35-41
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• 2014

Gas chromatography-mass spectrometry (GC-MS) methods have been used extensively in clinical steroid analyses. Evaluating the metabolic ratios of precursors to products by accurate quantification of individual steroid levels in biological samples can reveal the activities of enzymes associated with steroid metabolism. This review article discusses the impact of GC-MS-based steroid profiling on our understanding of the biochemical role of steroids and their metabolic enzymes in hormone-dependent diseases, such as congenital adrenal hyperplasia (CAH), cortisol-mediated hypertension, apparent mineralocorticoid excess (AME), male-pattern baldness, and breast and thyroid cancers. Steroid profiling is a comprehensive analytical technique that can be applied whenever the highest specificity is required and may be a reasonable initial diagnostic approach.

• Mass Spectrometry Letters
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• v.8 no.4
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• pp.90-97
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• 2017

Androgenic anabolic steroids (AASs) are synthetic derivatives of testosterone with a common structure containing cyclopentanoperhydrophenanthrene nucleus. Their use enhances the muscle building capacity and is beneficial during performance. The AASs are one of the most abused group of substances in horse doping. Liquid chromatography tandem mass spectrometry ($LC/MS^n$) has been successfully applied to the detection of anabolic steroids in biological samples. However, the saturated hydroxysteroids viz: nandrolone, $5{\alpha}-estrane-3{\beta}$, $17{\alpha}-diol$ exhibit lower detection responses in electrospray ionisation (ESI) because of their poor ionisation efficiency. To overcome this limitation pre-column chemical derivatization has been introduced to enhance their detection responses in $LC-ESI-MS^n$ analysis. The aim of present study was to develop a sensitive method for identification and confirmation of nandrolone and its metabolite in horse urine incorporating pre-column derivatization using picolinic acid. The method consists of extraction of targeted steroid conjugates by solid phase extraction (SPE). The eluted steroid conjugates were hydrolysed by methanolysis and free steroids were recovered with liquid-liquid extraction. The resulting steroids were derivatized to form picolinoyl esters and identification was done using LC-ESI-MS/MS in positive ionization mode. The picolinated steroid adduct enhanced the detection levels in comparison to underivatized steroids.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2007.11a
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• pp.57-64
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• 2007

Metabolic interactions of the three major cannabinoids, ${\Delta}^9$-tetrahydrocannabinol (THC), cannabidiol (CBD), and cannabinol (CBN) with steroid hormones were investigated. These cannabioids concentration-dependently inhibited $3{\beta}$-hydroxysteroid dehydrogenase and $17{\alpha}$-hydroxylase in rat adrenal and testis microsomes. CBD and CBN were the most potent inhibitors of $3{\beta}$-phydroxysteroid dehydrogenase and progesterone $17{\alpha}$-hydroxylase, respectively, in rat testis microsomes. Three cannabinoids highly attenuated hCG-stimulated testosterone production in rat testicular interstitial cells. These cannabinoids also decreased in levels of mRNA and protein of StAR in the rat testis cells. These results indicate that the cannabinoids could interact with steroid hormones, and exert their modulatory effects on endocrine and testicular functions. Metabolic interaction of a THC metabolite, $7{\beta}$-hydroxy-${\Delta}^8$-THC with steroids is also investigated. Monkey liver microsomes catalyzed the stereoselective oxidation of $7{\beta}$-hydroxy-${\Delta}^8$-THC to 7-oxo-${\Delta}^8$-THC, so-called microsomal alcohol oxygenase (MALCO). The reaction is catalyzed by CYP3A8 in the monkey liver microsomes, and required NADH as well as NADPH as an efficient cofactor, and its activity is stimulated by some steroids such as testosterone and progesterone. Kinetic analyses revealed that MALCO-catalyze reaction showed positive cooperativity. In order to explain the metabolic interaction between the cannabinoid metabolite and testosterone, we propose a novel kinetic model involving at least three binding sites for mechanism of the metabolic interactions.

• Fisheries and Aquatic Sciences
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• v.4 no.2
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• pp.70-74
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• 2001

To examine the production of steroids with potential oocyte maturation-inducing activity in the spotted flounder, Verasper variegatus, we have incubated post-vitellogenic oocytes (0.82­0.95mm in diameters) with radiolabeled pregnenolone and $17\alpha-hydroxyprogesterone$. The resulting metabolites were analyzed by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). The two main metabolites (progestogens) found in both incubations co-migrated with $17\alpha-hydroxy$, $20\alpha-dihydroprogesterone$ $(17\alpha, 20\alpha OHP)$ and $17\alpha-hydroxy,\;$20\beta-dihydroprogesterone$ (17 a20{30HP). Additional chromatography by HPLC and TLC confirmed the presence of radioactive $17\alpha, 20\alpha OHP$ and a large amount of unknown metabolite. The present study did not reveal in vitro formation of $l7\alpha 20\beta OHP$. Although 1$l7\alpha 20\beta OHP$ was found in a small amount, the synthesis of this steroid suggests that it may play a role in regulating the oocyte maturation process in the spotted flounder.

• Mass Spectrometry Letters
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• v.3 no.1
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• pp.4-9
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• 2012

• Journal of Nutrition and Health
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• v.12 no.1
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• pp.9-16
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• 1979

Cholecalciferol은 피하에서 자외선과 체온의 작용을 받아 7-dehydrocholesterol로부터 Previtamin D를 거쳐 합성이 되며 이어서 간에 빨리 축적, 25 hydroxylation을 거치게 되고 신장에서 가장 활성을 띤 형태인 $1.25-(OH)_{2}CC$로 변하게 된다. 한편 신장에서는 체내의 Ca, P이 정상으로 존재하게 되면 1-hydroxylation이 억제되는 대신 24-hydroxylation이 일어나 또 다른 active form인 $24,\;25-(OH)_{2}CC$가 되는데 24-hydroxylation의 역활이 무엇인가에 대해서는 아직 구체적으로 밝혀지지 않았다. $24,\;25-(OH)_{2}CC$나 $1.25-(OH)_{2}CC$는 모두 공통적으로 또 다른 active form인 $1.24,\;25-(OH)_{3}CC$를 형성할 수도 있다. 그중 $1.25-(OH)_{2}CC$는 Steroid H.으로 일컬어지기도 하는 Vit. D metabolite중에서 가장 활성을 가진 형태이며 표적기관으로 크게 소장, 뼈, 신장을 들 수 있다. 소장에서의 역활은 무엇보다도 Ca흡수에 관련되는 것으로 소장에서의 Ca흡수와 Ca BP합성에 관여한다. 골격 형성과 뼈의 mineralization에 관여하는 Vit. D metabolite를의 효과에 관해서는 아직까지 일관성있는 보고가 없다. 한편 $1.25-(OH)_{2}CC$는 side chain oxidation을 거쳐 $CO_{2}$와 미지의 물질을 생성하는데 이 mechanism이 어떤 의미를 갖는지는 분명치 않다. 그밖에 또 다른 표적기관으로서 최근 타액선의 존재가 알려졌으며 Vit. D가 배설되는 경로에 대해서는 새로운 바가 없다. Vit. D가 담즙을 통해서 우선적으로 배설되고 소량이 뇨를 통해 배설되는데 metabolite들의 배설경로는 더욱 규명되어야 할 과제이다.

• Bulletin of the Korean Chemical Society
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• v.35 no.5
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• pp.1409-1412
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• 2014

Sex hormones are important metabolites in vertebrates' development and reproduction. For rapid screening sex hormones, matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is one of the promising analytical platforms, but MALDI MS faces many challenges in detecting steroids such as low ionization efficiency and matrix background interference. One potential strategy to overcome matrix interference in the low m/z region is using a cyclodextrin (CD)-supported matrix for steroid analysis since CD-supported matrixes are known to effectively suppress matrix-related ion signals. In this study, we aimed to find the optimal CD-supported matrix for the analysis of the nonderivatized sex steroids. Our results showed that the ${\alpha}CD$-supported 2,5-dihydroxybenzoic acid (DHB) matrix efficiently ionized all three major classes of sex hormones, estrogens, androgens, and progestagens, with low or no matrix background and also with high sensitivity. In addition, the ${\alpha}CD$-supported DHB matrix mainly generated molecular ions or protonated ions of sex hormones, and this enabled us to obtain information-rich tandem mass spectra which potentially lead to unambiguous identification of steroid species from complex metabolite mixtures.

• Korean Journal of Animal Reproduction
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• v.3 no.2
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• pp.32-41
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• 1979

A series of experiment was conducted to determine the concentrations of progesterone and estradiol and metabolite contents in the serum of 26 Korean native cows raised at Alpine Experiment Station during the period of late pregnancy. Blood samples were collected by jugular puncture from individual cow at 5 day intervals from 30 days prepartum to 5 days prepartum and daily collected from 5 days prepartum to the day of parturition. Progesterone and estradiol concentrations in the serum were analyzed by Radioimmunoassay (R.I.A) method and serum metabolite contents were analyzed by autoanalzer MT II system. The following are summary of the results obtained: 1. Progresterone concentrations during the late preganacy were maintained at high level (5.12-11.70ng/$m\ell$) from 30 days prepartum to 8 days prepartum and fell rapidly from 5.12$\pm$1.07ng/$m\ell$ at 2 dyas prepartum to 1.48$\pm$0.32ng/$m\ell$ at 24 hrs prepartum. 2. Estradiol levles during the late pregancy increased gradually from 33.76$\pm$13.64pg/$m\ell$ at 30 days prepartum to 92.15$\pm$11.91pg/$m\ell$ at 11-15 days prepartum and increased thereafter sharply to a ranges of 161.76-238.4pg/$m\ell$ and were maintained at this increased levle until 24 hrs prepartum and decreased to 91.40pg/$m\ell$ at the parturition. 3. The correlation coefficients were found to be 0.2440 for cholesterol-progesterone relationship and -0.2552 for cholesterol-estradiol relationship, but there were statistically insignificant. 4. The changes in total protein contents during the late pregnancy were similar patterns to those of globulin and were maintained at high level only from 15 days to 5 days prepartum. 5. Glutamic oxaloacetate transaminase (GOT) levels were increased from 59.80$\pm$3.56u/$\ell$ at 90 days prepartum to 93.32$\pm$7.27u/$\ell$ at the day of parturition, but alkaline phosphatase levels were remained steady. 6. The levels of blood urea nitrogen, glucose and calcium remained almost constant during the late pregnancy. However, glucose concentration increased around the time of parturition.

• Analytical Science and Technology
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• v.11 no.5
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• pp.353-359
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• 1998

Danazol, one of the IOC banned substances, is a synthetic steroid which stimulates the synthesis of cellular protein with multiple and diverse biologic effects. To confirm the androgenic effects of danazol, levels of eight endogenous steroids and its major metabolite in human urine were simultaneously analyzed by selected ion monitoring (SIM) of GC/MS after oral administration. The recovery range of this method was 71.59%~93.56% and the RSD values of precision and accuracy test were 1.87%~10.48% and 1.32%~11.25%, respectively. The limits of detection of most of the drugs were $0.01{\sim}0.05{\mu}g/mL$ and calibration was carried out using urine spiked with each endogenous steroid and ethisterone standard at a concentration of 0.1, 0.5, 1.0, 10, 20 and $50{\mu}g/mL$ and with $10{\mu}g/mL$ of internal standard. Correlation coefficients varied between 0.963 and 0.991. The endogenous steroid profiling is one of valuatle tool for decteation of anabolic steroids.