• Asian-Australasian Journal of Animal Sciences
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• v.20 no.12
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• pp.1832-1842
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• 2007

Cytochrome P450 aromatase is responsible for the biosynthesis of estrogen. It is also responsible for the endogenous production of 19-nortestosterone (nandrolone), an anabolic androgen unique to pigs. Plasma concentrations of 19-nortestosterone are highest between two and four weeks after birth in male pigs. In the present study, the physiology of 19-nortestosterone was investigated by measuring the mRNA levels of steroidogenic enzymes, estrogen receptors and androgen receptor in the tissues of growing pigs. The expression of aromatase, 17${\alpha}$-hydroxylase and 3${\beta}$-hydroxysteroid dehydrogenase in the testes of male piglets increased between birth and two weeks of age, and then decreased progressively. Similar developmental expressional patterns were observed for 17${\alpha}$-hydroxylase and 3${\beta}$-hydroxysteroid dehydrogenase in the ovaries of female piglets, but without significant aromatase expression. The major form of aromatase expressed in the testes of piglets was identified as type I. Expression of estrogen receptor-${\alpha}$ and -${\beta}$and androgen receptor genes was also detected in both testes and ovaries. A transient elevation of androgen receptor mRNA in male piglets at two weeks of age was also observed in testes. Significant expression of the androgen receptor gene, but not of estrogen receptor-${\alpha}$ and -${\beta}$ genes, was also demonstrated in adipose tissue and muscle. We conclude that the observed increase in the testicular expression of aromatase in male pigs could account for the production of large amounts of 19-nortestosterone at between two and four weeks of age in males. Androgen receptor and 19-nortestosterone appeared to be important for testicular development and might contribute to sexual dimorphism in body composition and muscle development in juvenile pigs.

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.593-598
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• 2007

The current study was undertaken to determine the effects of sex steroid hormones(estrogen, testosterone and 19-nortestosterone) on differentiation and proliferation of pig preadipocytes. The preadipocytes were isolated from the backfat of new-born female pigs by collagenase digestion. 10－8M and 10－7M sex steroid hormones were treated to the cultured preadipocytes. Sex steroid hormones treated during the early stage of cell growth did not affect differentiation and proliferation of preadipocytes. However, testosterone and 19- nortestosterone treated during the late stage of cell growth stimulated differentiation of pig preadipocytes.

• Journal of Animal Science and Technology
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• v.46 no.3
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• pp.315-324
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• 2004

Cytochrome P450 aromatase is the enzyme responsible for biosynthesis of female sex hormone(estrogen) and 19-nortestosterone(nandrolone), a unique steroid hormone endogenously synthesized in the pig. By use of RT-PCR coupled with DHPLC technique (WAVE analysis), expression pattern of isoforms of porcine cytochrome P450 aromatase gene was investigated. Relatively higher expression of aromatase mRNA was observed in testis than in ovary and this result accounted for the previous findings of higher blood estrogen level in male compared with female in this species. The result from the DHPLC demonstrated that PCR amplified DNA fragments of ovary and testis tissues. using unique PCR primers for all three types of aromatase genes, were different from those of type II and ill genes. Further nucleotide sequence analyses of the plasmid clones containing the PCR products revealed that nucleotide sequences of all clones were identical to type I aromatase gene(ovary type). Thus, the result from the present study indicates that the ovary and testis express the same type of aromatase gene. Therefore, the efficacy of DHPLC techniques used for this study helped us to analyze tissue-specific expression of isoform of genes containing the nucleotide sequences with high homology.

• Journal of Animal Science and Technology
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• v.52 no.1
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• pp.17-22
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• 2010

The current study was undertaken to determine the effects of sex steroid hormones (estrogen, testosterone and 19-nortestosterone) on proliferation and differentiation of preadipocytes of female and male pigs. The preadipocytes were isolated from the backfat of new-born female and male pigs by collagenase digestion and cultured in the $CO_2$ incubator. The concentration of $10^{-7}M$ and 10-6M sex steroid hormones were treated to the cultured preadipocytes. Regarding the effects on preadipocytes proliferation, high concentration ($10^{-6}M$) of all the three hormones increased proliferation of female preadipocytes,and only estrogen and testosterone increased proliferation of male preadipocytes. Regarding the effects on preadipocyte differentiation, all the three hormones increased differentiation of pig preadipocytes, regardless of hormone concentrations and sex of preadipocytes. The degree of stimulation of cell differentiation by sex steroid hormones was greater than that of cell proliferation.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.4
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• pp.501-510
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• 2007

The present study was conducted to establish primary bovine muscle satellite cell (MSC) culture conditions and to investigate the effects of various steroid hormones on transcription of the genes involved in muscle cell proliferation and differentiation. Of three different types of proteases (type II collagenase, pronase and trypsin-EDTA) used to hydrolyze the myogenic satellite cells from muscle tissues, trypsin-EDTA treatment yielded the highest number of cells. The cells separated by hydrolysis with type II collagenase and incubated on gelatin-coated plates showed an enhanced cell attachment onto the culture plate and cell proliferation at an initial stage of cell growth. In this study, the bovine MSCs were maintained in vitro up to passage 16 without revealing any significant morphological change, and even to when the cells died at passage 21 with decreased or almost no cell growth or deformities. When the cells were incubated in a steroid-depleted environment (DMEM(-)/10% CDFBS (charcoal-dextran stripped FBS)), they grew slowly initially, and were widened and deformed. In addition, when the cells were transferred to an incubation medium containing steroid (DMEM(+)/10% FBS), the deformed cells resumed their growth and returned to a normal morphology, suggesting that steroid hormones are crucial in maintaining normal MSC morphology and growth. The results demonstrated that treatments with 19-nortestosterone and testosterone significantly increased AR gene expression (p<0.05), implying that both testosterone and 19-nortestosterone bind with AR and that the hormone bound-AR complex up-regulates the genes of its own receptor (AR) plus other genes involved in satellite cell growth and differentiation in bovine muscle.

• Clinical and Experimental Reproductive Medicine
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• v.17 no.1
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• pp.21-28
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• 1990

19-nortestosterone(NORA)와 19-norandrostenedione(NT)는 정소내 aromatization과정중 중간 대사물로 검출된다. 본 연구는 이들을 장기간 투여하여 정소 및 부속기관의 무게, 혈청내 testosterone(T)의 농도, 정자형성에 미치는 영향을 조사하였다. NORA, NT 및 TE를 $300/50{\mu}l$농도로 주당 3회씩 12주간 정소에 직접 주사(intratesticular injection, i.t.)하였다. 또한 GnRH antagonist(RS68439)를 처리하여 혈청내 생식소자극호르몬 (GTH)을 감소시킨후 위 호르몬들을 동일방법으로 처리하여 이들의 보상작용을 조사하였다. NORA는 정소무게를 감소시키지 않았으나 GnRH antagonist를 처리하여 감소된 정소무게를 현저하게 보상하였다(P<0.05). NORA, NT, TE는 모두 부속기관의 무게를 증가시켰으며, RS68439가 감소시킨 부속기관의 무게를 현저히 증가시켰다. 그러나 이들은 부정소(epididymis)에는 영향을 주지않았으며 RS68439처리군에서는 보상작용을 나타내었다. 이들의 처리로 혈청내 LH농도는 완전히 감소하였으나 FSH의 농도에는 영향을 나타내지 않았다. 그리고 혈청내 T의 농도를 증가시켰다. NORA는 정자형성과정중 7단계의 spermatid의 수를 현저히 감소시켰다. 위 결과로 보아 NORA는 GnRH antagonist로 FSH의 분비가 억제된 쥐의 FSH분비를 촉진하며, T의 농도를 증가시켜 정자형성과정을 억제하는 것으로 추론된다.

• Journal of Pharmaceutical Investigation
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• v.1 no.1
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• pp.47-52
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• 1971

Application of the spectrophotometer to the analysis of 17 ${\alpha}-ethinyl$ estradiol and $17{\alpha}-ethinyl-19-nortestosterone$ acetate mixture in oral contraceptive has been accomplished. It is used Beckman Du Spectrophotometer as a apparatus. The petroleum ether extract of ethinyl estradiol is determined at $535\;m{\mu}$ and the chloroform extract of norethindrone acetate is determined at $380\;m{\mu}$ respectively. This analytical method is formed Lambert Beer's law. This method can be used to the analysis of ethinyl estradiol aid norethindrone acetate mixture in commercial dosage form of routine assay.

• Clinical and Experimental Reproductive Medicine
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• v.21 no.3
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• pp.305-314
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• 1994

19-norandrostenedione(19-NORA) is known as an intermediate in the metabolic pathway from androstenedione to estrone. Administration of esterified 19-nortestosterone, anabolic steroid, reduces serum gonadotropin and testosterone concentration, and results in reversible azoospermia in men. 19-NORA have been isolated from testis, but its function in testis is not clear yet. Therefore, this study was designed to determine the effect of 19-NORA on steroidogenesis and on spermatogenesis. 19-NORA was administrated by single intratesticular injection to adult male rats weighing 350-400 g in dose of 1 mg/50${\mu}l$. The serum and testis were collected on 1, 3, 7, 12, 48 hr after injection. The histological differences in testis were observed by routine paraffin method. The concentrations of testosterone and estradiol in serum and in left testis were determined by the conventional radioimmunoassays. One hour after 19-NORA treatment, serum concentrations of testosterone and estradiol increased significantly, compared to those of pre-treated(0 hr) group, and reduced gradually to the control level on 7 hour after injection. The concentration of testosterone in left testis increased slightly 1 hour after injection, and estradiol level increased significantly(p<0.05). Also, testosterone and estradiol level of control group revealed no difference with pre-treated (0 hr) group. Gonad index, structure of seminiferous tubules, and the number of step 7 th spermatid were simillar to control group. The present study suggests that the elevation of testosterone level results from increment of estradiol followed by the rapid metabolism of 19-NORA at 7 hour after injection, and then testosterone concentration may be recovered to control level by feedback mechanism of hypothalamus-hypothysis-testis axis.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.8
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• pp.1091-1101
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• 2009

In an attempt to understand the biochemical mechanism for the synthesis of the anabolic steroid, 19-nortestosterone, produced by prepubertal boar testes and its physiological role, normalized complementary DNA (cDNA) from boar testes was generated. DNA sequencing of 2,016 randomly selected clones yielded 794,116 base pairs of high quality nucleotide sequence. Computer-assisted assembly of the nucleotide sequence of each clone resulted in 423 contigs and 403 singletons including several genes for steroidogenic enzymes and molecules related to steroid metabolism. Analysis of gene expression pattern by use of the presently-fabricated cDNA microarray identified a number of genes that were differentially expressed during the postnatal development period in boar testes. Two genes of unknown function were identified to be highly expressed in the testis of 2-weeks-old neonatal boar. In addition, the sequencing of open reading frames of these genes revealed their homology with human alpha hemoglobin and Homo sapiens hypothetical LOC643669, transcript variant 1. Moreover, the transcripts of these genes were also detected in porcine muscle and adipocytes, in addition to Leydig cells of pigs.

• Animal cells and systems
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• v.16 no.6
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• pp.469-478
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• 2012

Sex hormones have long been considered to play an important role in bone turnover rate, periodontal diseases, and wound healing. We have studied the effect of porcine testis steroid extract (PTSE), an extract of porcine testes, which holds a good ratio of 19-nortestosterone (nandrolone), testosterone, androstenedione, $17{\beta}$-estradiol, and estrone, on the healing rate of a standardized full-thickness linear wound on the back of the rat. Skin punch or carbon dioxide ($CO_2$) laser methods were used to create the deep skin injury in two groups of animals. The animals were treated with the PTSE cream, control cream and Vaseline (control) to find out the effect in re-epithelialization, contraction, and formation of granulation and scar tissues. Histological examination after 21 days showed 100, 87.4, and 80.5% recovery of epidermis, dermis, and hypodermis, respectively in the PTSE-treated animals. Similarly, on the 15th day of treatment, complete healing of intact skin was observed in the PTSE cream-treated animals among the laser radiation group. Even though the beginning of re-epithelialization phase and completion of serum crust formation was also observed in the base cream- and Vaseline-treated animals respectively, the complete healing cycle was observed only in the PTSE-treated group. The white blood cell count in the PTSE-treated group showed that PTSE cream is nontoxic to animals.