Testicular Toxins Research Articles

Male reproductive toxicity of four bisphenol antioxidants in mice and rats and their estrogenic effect

Male mice and rats were fed a diet containing four bisphenol antioxidants, 2,2'-methylenebis(4-ethyl-6-tert-butylphenol) (ME), 2,2'-methylenebis(4-methyl -6-tert-butylphenol) (MM), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol) (BM), or 4,4'-thiobis(3-methyl-6-tert-butylphenol) (TM) at levels of 0.06-0.25% for 2 months. BM and TM decreased epididymal, seminal vesicular, prostate and preputial weights, and injured seminiferous tubules in mice in a dose-dependent fashion. BM and TM also reduced sex accessory organ weights and sperm production capacity in rats, but MM and ME were more toxic to rats than BM and TM. ME and MM did not bind ERalpha up to 10(-3) M, while BM and TM competitively bound ERalpha against beta-estradiol (E2). Fifty percent inhibitory concentrations (IC50 s) of BM, TM, and bisphenol A (positive control) against E2-binding were 7.3 x 10(-6) M, 1.8 x 10(-5) M, and 1.4 x 10(-5) M, respectively. When ovariectomized (OVX) mice were sc administered TM at doses of 60 and 300 mg/kg/day for 4 days, or when OVX mice were fed BM in the diet at a level of 0.25% for 2 months, uterine weight was significantly increased. These results suggest that BM and TM are weakly toxic, possibly through an estrogenic mechanism to male reproductive organs in mice as well as rats, while MM and ME may be the direct testicular toxins in rats but not mice.

The response of adult rat sertoli cells, immortalized by a temperature-sensitive mutant of SV40, to 1,2-dinitrobenzene, 1,3-dinitrobenzene, 2,4-dinitrotoluene, 3,4-dinitrotoluene, and cadmium.

In this study we test the hypothesis that immortalized adult rat Sertoli cells respond to known testicular toxins in a similar manner to Sertoli cells tested in vivo and in primary culture. This cell line was developed by immortalizing adult rat Sertoli cells with the temperature-sensitive mutant of SV40, ts255, such that the cells proliferate at the permissive temperature of 33 degrees C but express differentiated characteristics at the nonpermissive temperature of 40 degrees C. Confluent monolayers, grown at 33 degrees C or 40 degrees C, were exposed to a range of concentrations of dinitrobenzene (DNB) or dinitrotoluene (DNT) isomers or to cadmium chloride. Cellular response was assessed by neutral-red cell viability assay and ultrastructural changes. Cells grown at 40 degrees C were sensitive to lower concentrations of each toxicant than were cells grown at 33 degrees C. 1,2-DNB was more toxic than 1,3-DNB, and 3,4-DNT was more toxic than 2,4-DNT, as judged by the neutral-red cell viability assay. Ultrastructurally, cells treated with 1,2-DNB or 2,4-DNT showed increased numbers of autophagic vesicles compared to controls. Intercellular penetration of ruthenium red demonstrated breached tight junctions in 1,2-DNB and cadmium-treated cells. From these observations, we conclude that this cell line can serve as a model for studying toxic mechanisms in adult Sertoli cells.

Classification of toxin-induced changes in 1H NMR spectra of urine using an artificial neural network

NMR spectra of urine from rats treated with a range of liver, kidney and testicular toxins at various doses were measured and classified using neural network methods. Toxin-induced changes in the levels of 18 low molecular weight endogenous urinary metabolites were assessed using a simple semi-quantitative scoring system. These scores were used as input to an artificial neural network, the use of which has been explored as a means of predicting the class of toxin. With this limited data set, based only the level of the maximal changes of these 18 metabolites, the network was able to predict the class and hence target organ of the toxins. Renal cortical toxicity was well predicted as was liver toxicity. The few examples of renal medullary toxins in the data set resulted in relatively poor training of the network although correct classification was still possible.

The Influence of Phthalate Esters on Leydig Cell Structure and Function in Vitro and in Vivo

Phthalate esters are widely used in the manufacture of plastics and have been shown to cause testicular toxicity, purportedly, by targeting the Sertoli cell alone. Recent evidence, however, indicates that a paracrine control exists between Sertoli and Leydig cells and the breakdown of one component of this relationship is therefore detrimental to normal function. However, no data that explore the influence of testicular toxins on Leydig cell structure and function have been published hitherto. The preliminary studies reported here were initiated to test the hypothesis that phthalate intoxication may adversely alter Leydig cell structural and functional integrity. Four phthalate esters, namely, di(2-ethylhexyl) phthalate (DEHP), di- n-pentyl phthalate (DPP), di- n-octyl phthalate (DOP), and diethyl phthalate (DEP) were investigated in vivo and their monoesters (MEHP, MPP, MOP, and MEP, respectively) in vitro for indications of Leydig cell toxicity in the rat. Rats were dosed by oral gavage with 2 g phthalate diester/kg/day in corn oil vehicle for 2 days, while Leydig cell primary cultures were incubated with 1000 μ M monoester for 2 hr. Light and electron microscopy were undertaken to determine the type and degree of any changes. Phthalate esters exerted a direct effect on Leydig cell structure and function (as determined by testosterone output) with correlation of the in vitro and in vivo effects of MEHP (DEHP) and MOP (DOP). No effects on Leydig cell structure or function were seen with MPP (DPP), although Sertoli cell cytoplasmic rarefaction and vacuolation were observed in vivo. DEP produced Leydig cell ultrastructural alterations in vivo. We conclude that individual phthalate esters may exert effects on both Sertoli and Leydig cells or one cell type alone.

The modulating effects of antioxidants in rat embryos and Sertoli cells in culture.

The male and female reproductive systems are targets for the toxicity of a wide range of compounds. There is a paucity of information regarding the modulating effects of antioxidants in such systems. Enzymically generated oxygen radicals have been shown to be toxic and/or mutagenic in a variety of in vitro test systems. It is known that vitamins C and E can modify responses in such systems. Malformations and growth reductions have been observed in whole rat embryo cultures in this laboratory after treatment with the oxygen radical generating system of xanthine/xanthine oxidase. Groups of 9.5-day-old rat embryos were treated with this system with or without vitamin C or E. Vitamin C at the doses given totally abolished neural suture defects while vitamin E only partially did so. Vitamins C and E administered alone had no effect on the embryos. Germ cell detachment has been shown to occur in mixed cultures of Sertoli and germ cells in response to some known in vivo testicular toxins. Such cultures were also treated with the oxygen radical generating system of xanthine/xanthine oxidase. There was an increase in germ cell detachment with this treatment which was reduced by vitamin C but not by vitamin E at the doses administered. These findings would suggest that vitamin supplementation could protect somatic cells of reproductive systems against toxins that act through oxygen radical mechanisms.

Pig Leydig cell culture: A useful in vitro test for evaluating the testicular toxicity of compounds

In vivo studies have shown that the testis is a target organ for drugs and chemicals. In order to evaluate the testicular toxicity of compounds and to identify the mechanisms of their toxicity, we have developed a miniaturized primary culture of immature pig Leydig cells. Five well-known drugs with differing mechanisms of toxicity on testicular functions were tested to validate the model. Testosterone and progesterone secretion were measured to evaluate testicular function. Cell viability was assessed quantitatively using a colorimetric assay based on the reduction of a tetrazolium salt (3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide) which stains viable cells only, thus allowing discrimination between specific inhibitors of Leydig cell function and nonspecific cytotoxic drugs. Ketoconazole and aminoglutethimide inhibited both testosterone and progesterone secretion, but without modifying cell viability. Spironolactone specifically blocked testosterone secretion and increased progesterone concentration without inducing cell mortality. Cycloheximide altered testicular steroid secretion by another mechanism of action. Chlorpromazine, which interferes with the secretion of gonadotropins in vivo, produced a significant inhibition of progesterone and testosterone secretion as a result of the cytotoxic effects of the drug. In conclusion, this in vitro test enables one to discriminate accurately between specific and nonspecific inhibitors of steroidogenesis and could reduce the number of false positives when screening for potential testicular toxins.

Isolated rat seminiferous tubules synthesize guanidoacetic acid and creatine from arginine

Conference Article| June 01 1989 Isolated rat seminiferous tubules synthesize guanidoacetic acid and creatine from arginine NIGEL P. MOORE; NIGEL P. MOORE *Toxicology Unit, The School of Pharmacy, 29/39 Brunswick Square, London WC1N 1AX, U.K. Search for other works by this author on: This Site PubMed Google Scholar JOHN A. TIMBRELL; JOHN A. TIMBRELL *Toxicology Unit, The School of Pharmacy, 29/39 Brunswick Square, London WC1N 1AX, U.K. Search for other works by this author on: This Site PubMed Google Scholar TIM J.B. GRAY TIM J.B. GRAY †British Industrial Biological Research Association, Woodmansterne Road, Carshalton, Surrey SM5 4DS, U.K. Search for other works by this author on: This Site PubMed Google Scholar Biochem Soc Trans (1989) 17 (3): 520–521. https://doi.org/10.1042/bst0170520 Article history Received: November 25 1988 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Cite Icon Cite Get Permissions Citation NIGEL P. MOORE, JOHN A. TIMBRELL, TIM J.B. GRAY; Isolated rat seminiferous tubules synthesize guanidoacetic acid and creatine from arginine. Biochem Soc Trans 1 June 1989; 17 (3): 520–521. doi: https://doi.org/10.1042/bst0170520 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Society Transactions Search Advanced Search This content is only available as a PDF. © 1989 Biochemical Society1989 Article PDF first page preview Close Modal You do not currently have access to this content.

The effects of two testicular toxins on the ultrastructural morphology of mixed cultures of sertoli and germ cells: A comparison with In vivo effects

The effects of two testicular toxins on the ultrastructural morphology of mixed cultures of sertoli and germ cells: A comparison with In vivo effects

Effect of some phthalate esters and other testicular toxins on primary cultures of testicular cells

Mixed cultures of Sertoli and germ cells were prepared from rat testes and their response to some model testicular toxins was studied. Cultures consisted of a monolayer of Sertoli cells to which clusters of spermatocytes and spermatogonia adhered. With time in culture, germ cells progressively detached from the Sertoli cells into the medium. Addition of mono-(2-ethylhexyl) phthalate (MEHP) to the culture medium resulted in a concentration-dependent increase in the rate of germ-cell detachment over the range 10 −7–10 −4 m. No such effect was produced by di-(2-ethylhexyl) phthalate or 2-ethylhexanol. An increased rate of germ-cell detachment was also produced by other phthalate monoesters known to cause testicular damage in vivo, whereas similar concentrations of a number of monophthalates not known to affect the testis in vivo had no such effect on the cultures. Known age and species differences in the testicular toxicity of di-(2-ethylhexyl) phthalate could be reproduced in cultures treated with MEHP. There was little effect on the viability of either germ cells or Sertoli cells at concentrations of MEHP that caused marked germ-cell detachment, but there were changes in Sertoli-cell morphology. Increased germ-cell detachment was also observed in cultures treated with 10 −7–10 −4 m-AF1312/TS, a compound that affects Sertoli cells in vivo, but was not seen in cultures exposed to a range of other testicular toxins with different target cells in the testis. Thus, the effects produced by phthalate monoesters in vitro may reflect damage to the Sertoli cells. Testicular cell cultures could be of value both for screening compounds and for studying underlying mechanisms of testicular toxicity.

Is ethanol a testicular toxin?

A method is described by which the testis of the rat can be isolated and selectively perfused in vitro to examine the effect of potential gonadal toxins. Using this system, the effect of ethanol at levels commonly found in the plasma of nonalcoholic men who drink alcohol was evaluated. Ethanol was found to significantly reduce (p less than 0.01) testosterone production and secretion by the isolated perfused testis. The advantage of such a system is that it permits examination of the effect of specific testicular toxins, such as alcohol, independent of hepatic metabolism and/or hypothalamic-pituitary suppression by such substances. These results suggest that ethanol, independent of hepatic metabolism and/or hypothalamic-pituitary suppression, is a direct testicular toxin.

Sex-determined differences in drug susceptibility

not received. EFFECT OF ALCOHOL ON GONADAL FUNCTION DAVID H. VAN THIEL*, JUDITH S. GAVALER, PATRIC’IA K. EAGON and ROGER LESTER Departments of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15621, and Unioersity of Texas, Houston, TX 77025 (rr.S.A.) During the past decade there has been an increasing appreciation of the fact that ethanol is a tissue toxin which adversely effects multiple organs including the endocrine system. In particular it has been recognized that ethanol impairs the functioning of the hypothalamic-pituitary-gonadal axis. Thus, hypogonadism is seen commonly in alcoholic men. Such hypogonadism is manifested by a high prevalence of decreased libido and/or impotence (70 to 80%) and testicular atrophy with infertility (70 to 80%). Histologic examination of testicular tissues obtained from such individuals show seminiferous tubular atrophy with a marked loss of normal germ cells and a high prevalence of grossly abnormal germ cells. In addition to demonstrating evidence of hypogonadism, chronic alcoholic men also are hyperestrogenizied. Thus, a female escutcheon develops in 50%, gynecomastia in 2096, spider angiomata and palmer erythema in 40 to 50%. Unlike impotence, which commonly is experienced with acute alcohol abuse, these signs suggest irreversible hepatic disease (cirrhosis). In contrast, considerable evidence has accrued to suggest that sexual dysfunction is an early finding in alcoholabusing men and animals and can occur in the absence of histologic liver disease. Recent clinical studies have provided evidence that alcohol and/or its principal metabolite, acetaldehyde, are testicular toxins. Thus, testosterone concentrations have been shown to fall transiently in normal men after alcohol ingestion. Similarly, a dose-dependent fall in testosterone has been reported in mice given ethanol. Moreover, histologic and biochemical testicular damage has been reported in alcohol-fed rats. Most recently, perfusion of the isolated perfused rat testes with ethanol over a dose range of 50 to 300 mg/dl has been shown to suppress testosterone production and secretion by as much as 75%. The specific mechanisms by which alcohol adversely effects Leydig cell and/or seminiferous tubular function are, as yet, unknown. It is possible that vitamin A bioactivation is altered as a result of alcohol metabolism. Alcohol metabolism also may shift the balance between NAD and NADH, thus limiting synthesis. Evidence also is accumulating to

Acetaldehyde and ethanol are testicular toxins

Acetaldehyde and ethanol are testicular toxins