Direct effects of the pineal hormone melatonin on testosterone synthesis of Leydig cells in Djungarian hamsters (Phodopus sungorus) in vitro

A previous study in the rat (Pollard et al. 1990) established that caffeine, when administered during pregnancy, significantly inhibited the differentiation of the seminiferous cords and subsequent Leydig cell development in the interstitium. However, that study could not distinguish between the direct effects of caffeine and/or the intermediary secondary toxic effects of metabolites such as theophylline and theobromine. Because the fetus lacks the appropriate enzyme systems, clearance of toxic substances takes place via the placenta and maternal liver. Thus, a suitable in vitro system can effectively differentiate between primary and secondary drug effects. In the present study, 13-day-old fetal testis, at the stage of incipient differentiation, were cultured for 4 days in vitro in the presence of graded doses of caffeine, theophylline or theobromine. It was found that explants exposed to caffeine or theobromine differentiated normally, developing seminiferous cords made up of Sertoli and germ cells, soon followed by the differentiation of functionally active Leydig cells appearing in the newly formed interstitium. However, explants exposed to theophylline failed to develop seminiferous cords and, as a consequence, Leydig cells. In conclusion, insights obtained from different experimental methods, such as organ culture or whole organism studies, are not always identical. It may be prudent, therefore, to take into account that certain experimental techniques, despite providing valuable information, may require confirmation by other test methods in order to obtain an in-depth understanding of mechanisms of action involved.

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Are ovine Leydig cells able to aromatize androgens?

Reproduction Fertility and Development ◽

10.1071/r96038 ◽

1997 ◽

Vol 9 (2) ◽

pp. 193 ◽

Cited By ~ 27

Author(s):

Barbara Biliska ◽

Marcin Le´sniak ◽

Barbara Schmalz

Keyword(s):

Aromatase Inhibitor ◽

Incubation Period ◽

Immunohistochemical Staining ◽

Leydig Cells ◽

Culture Medium ◽

Aromatase Activity ◽

Dependent Manner ◽

Dose Dependent ◽

Testosterone Synthesis

The conversion of testosterone into oestradiol by ovine Leydig cells culturedin vitrowas studied using the non-steroidal aromatase inhibitor CGS 16949A. Additionally, aromatase activity was detected by immunohistochemical staining of cultured Leydig cells or cryosections. The cells were obtained from testes of Polish Mountain rams 5–6 months old (immature) or 12–15 months old (mature). Leydig cells were cultured alone (controls) or incubated for 6 h in the presence of testosterone. Aromatase inhibitor was then added to the cultures which were incubated for a further 18 h. After a 24-h incubation period, testosterone and oestradiol secretion were determined by testing the culture medium using radioimmunological methods. The addition of testosterone to the culture medium enhanced oestradiol synthesis, suggesting that exogenous testosterone could also be aromatized to oestradiol by ovine Leydig cells in vitro. In the presence of CGS 16949A, the conversion of testosterone to oestradiol was significantly suppressed in a dose-dependent manner. All Leydig cells obtained from testes of mature rams and stained immunohistochemically were positive for aromatase, whereas Leydig cells from immature males were negative. The localization of immunoreactive aromatase appeared to be dependent on the age of the donor ram. It is suggested therefore, that mature Leydig cells in the ram are not only the site for testosterone synthesis, they are also capable of converting androgens into oestrogens.

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Effects of clodronate-containing liposomes on testicular macrophages and Leydig cells in vitro

Journal of Endocrinology ◽

10.1677/joe.0.1550087 ◽

1997 ◽

Vol 155 (1) ◽

pp. 87-92 ◽

Cited By ~ 7

Author(s):

DE Brigham ◽

G Little ◽

YO Lukyanenko ◽

JC Hutson

Keyword(s):

Direct Effect ◽

Dose Response ◽

Leydig Cell ◽

Leydig Cells ◽

Direct Effects ◽

Testosterone Production ◽

Identical Response ◽

Testicular Macrophages

We undertook the present studies to determine if clodronate-containing liposomes have direct effects on Leydig cells. Macrophages and Leydig cells were isolated and maintained separately in culture. Following treatment with clodronate-containing liposomes, macrophages were killed in a dose-response fashion over a range of 5-200 microliters liposomes. By comparison, a 500 microliters dose was required to kill Leydig cells, but this was not dependent upon clodronate since liposomes containing buffer elicited an identical response. The concentration of testosterone in medium from Leydig cells treated with clodronate-containing liposomes was significantly reduced compared with untreated cells. However, we subsequently found that liposomes can adsorb testosterone. Therefore, testosterone production was determined at various times following removal of liposomes from Leydig cells, thereby circumventing this complication. It was found that testosterone production was not altered by liposomes under these conditions. Finally, free clodronate had no effect on testosterone production, even at doses representing the amount present within the 500 microliters dose of liposomes. In summary, clodronate-containing liposomes killed testicular macrophages at a far smaller dose than required to kill Leydig cells. Most importantly, neither liposomes no free clodronate had a direct effect on testosterone production. Thus, clodronate-containing liposomes represent a valuable tool to study Leydig cell-macrophage interactions.

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ANDROGEN SYNTHESIS BY THE TESTES AND ADRENAL GLANDS OF RATS POISONED WITH CADMIUM CHLORIDE

Journal of Endocrinology ◽

10.1677/joe.0.0350185 ◽

1966 ◽

Vol 35 (2) ◽

pp. 185-192 ◽

Cited By ~ 25

Author(s):

A. FAVINO ◽

A. H. BAILLIE ◽

K. GRIFFITHS

Keyword(s):

Leydig Cells ◽

Cadmium Chloride ◽

Tunica Albuginea ◽

Hydroxysteroid Dehydrogenase ◽

Testicular Tissue ◽

Androgen Synthesis ◽

Cadmium Poisoning ◽

Dehydrogenase Reaction ◽

Testosterone Synthesis

SUMMARY Androgen synthesis after administration of cadmium chloride to rats has been studied histologically, histochemically and biochemically. Incubation in vitro of testicular tissue removed 10 days after cadmium administration revealed markedly decreased testosterone synthesis. After 100 and 150 days, testosterone synthesis in vitro had increased progressively and significantly, but there was a marked decrease in the testosterone: androstenedione ratio. Surviving Leydig cells, giving typical histochemical reactions for 3β-, 16β- and 17β-hydroxysteroid dehydrogenase, were observed under the tunica albuginea immediately after cadmium poisoning. Fifty days after the cadmium treatment, mesenchymal cells, giving a histochemical 3α- and 16α-hydroxysteroid dehydrogenase reaction, but no other hydroxysteroid dehydrogenase reaction of normal Leydig cells, grew into the testes from the tunica albuginea. Weight, citric acid and fructose contents of seminal vesicles of cadmium-treated rats fell nearly to castration levels, but showed some degree of recovery thereafter. Studies in vitro on adrenal tissue from cadmium-poisoned rats suggested that the rate of testosterone biosynthesis from pregnenolone was increased.

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ISOLATION AND CHEMICAL CHARACTERIZATION OF BIOACTIVE ALKALOID FROM ARGYREIA SPECIOSA LINN. HAVING ACTION ON ISOLATED RAT LEYDIG CELLS

Asian Journal of Pharmaceutical and Clinical Research ◽

10.22159/ajpcr.2019.v12i10.34789 ◽

2019 ◽

pp. 276-280

Author(s):

NIRAJ VYAS ◽

KANAN GAMIT ◽

MANAN RAVAL ◽

SAMIR PATEL

Keyword(s):

1H Nmr ◽

Leydig Cells ◽

Chemical Characterization ◽

Positive Control ◽

Flash Chromatography ◽

Spectral Studies ◽

Testosterone Synthesis ◽

Isolated Rat

Objective: Present study was aimed to isolate and chemically characterize bioactive constituent from alkaloid enriched fraction, prepared from roots of Argyreia speciosa Linn. Materials and methods: Literature review revealed presence of ergoline type of alkaloids in roots. Alkaloidal fraction was prepared and screened for its action on testosterone biosynthesis, in- vitro, using isolated rat leydig cells. Dehydroepiandosterone was used as positive control. This bioactive fraction was subjected to open column chromatography followed by flash chromatography, to isolate constituent. One compound (A1) was isolated from the fraction and its purity was ascertained using TLC and HPLC studies. A1 was chemically characterized by IR, Mass and 1H-NMR studies, to elucidate probable chemical structure. A1 was screened for action on testosterone synthesis too, using isolated rat Leydig cells model. The fraction was standardized with respect to amount of A1 present. Results: Alkaloidal fraction (1000 µg/ml) incubated Leydig cells showed nearly, 22 fold increase in testosterone content as compared to untreated cells. The studies also yielded increase in testosterone content, in cells treated with test fractions and as observed in case of positive control. TLC studies indicated that A1 might possess ergoline moiety in the structure. IR, Mass and 1H NMR spectral studies suggested that A1 might be N-methyl ergometrine. This was the first report included isolation and chemical characterization of N-methyl ergometrine from Argyreia speciosa. A1 (1000 µg/ml) was found to stimulate testosterone content, by 14.62 fold, in culture media of Leydig cells after incubation. Conclusion: The results of in vitro studies, confirmed that the standardized alkaloid fraction as well as A1 had ability to stimulate Leydig cells to secrete testosterone. A1 might be N-methyl ergometrine and being ergometrine derivative it might act through oxytocine receptors expressed on the Leydig cells and stimulates testosterone synthesis.

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