john
April 2nd 05, 10:38 PM
Study Links Monsanto's Roundup Herbicide to Hormone Disruption & Fetal
Damage
http://www.organicconsumers.org/monsanto/fetal030105.cfm
Posted 3/1/05
PRESS RELEASE
Pr. Gilles-Eric SERALINI's group in the University of Caen (Normandy,
France) just published original results concerning the toxicity of
Roundup. Il is one of the most used herbicides worldwide and the most
used with genetically modified plants (GMOs).
The majority of GMOs commercialized in the world are designed for food
and feed. These plants have been modified to remain alive after
herbicide absorption, this herbicide being spread on the cultures.
This greatly facilitates its use, as well as the presence of its
residues in the food chain. It is also evoked as a common pollutant in
rivers.
It is shown in this work that human placental cells are very sensitive
to Roundup, to concentrations lower than the agricultural use. This
could explain miscarriages and premature births in the United States in
farmers. Moreover, below toxic levels, the effects of Roundup are
measured on the synthesis of sexual hormones; this allow to classify
this herbicide in potential endocrine disruptors. Finally, the effects
of Roundup are always greater than those of glyphosate, which is known
as its active compound.
This work was supported in particular by CRIIGEN (www.crii-gen.org
http://www.crii-gen.org/
and by The "Fondation pour une Terre Humaine"
Contact : Pr. Gilles-Eric SERALINI, tel. 33 2 31 56 54 89,
>
Environmental health perspective
Differential effects of glyphosate and Roundup
on human placental cells and aromatase
Sophie Richard, Safa Moslemi, Herbert Sipahutar, Nora
Benachour, Gilles-Eric Seralini
doi:10.1289/ehp.7728 (available at http://dx.doi.org/)
Online 24 February 2005
Abstract Roundup is a glyphosate-based herbicide used worldwide including
on most
genetically modified plants in which it can be tolerated. Its residues may
thus enter the
food chain and glyphosate is found as a contaminant in rivers. Some
agricultural workers using
glyphosate have pregnancy problems, but its mechanism of action in mammals
is questioned. Here we
show that glyphosate is toxic on human placental JEG3 cells within 18 hr
with concentrations
lower than the agricultural use, and this effect increases with
concentration and time,
or in the presence of Roundup adjuvants. Surprisingly, Roundup is always
more toxic than its
active ingredient. We tested its effect on aromatase with lower non-toxic
concentrations, the
enzyme responsible for estrogen synthesis. The herbicide acts as an
endocrine disruptor on
aromatase activity and mRNA levels, and glyphosate interacts within the
active site of the purified
enzyme, but its effect is facilitated by Roundup formulation in microsomes
or in cell culture. We
conclude that endocrine and toxic effects of Roundup and not only
glyphosate can be observed in
mammals. We suggest that the presence of Roundup adjuvants enhances
glyphosate
bioavailability and / or bioaccumulation.
************************************************** **************************
This GMO news service is underwritten by a generous grant from the Newman's
Own Foundation, edited by Thomas Wittman and is a production of the
Ecological Farming Association www.eco-farm.org <http://www.eco-farm.org/
************************************************** **************************
Research Article
Differential effects of glyphosate and Roundup on human placental cells
and aromatase
Sophie Richard, Safa Moslemi, Herbert Sipahutar, Nora Benachour,
Gilles-Eric Seralini
http://ehp.niehs.nih.gov/docs/2005/7728/abstract.html
Abstract in PDF
This EHP-in-Press article has been peer-reviewed, revised, and accepted for
publication. The EHP-in-Press articles are completely citable using the
assigned DOI code for the article. This document will be replaced with the
copyedited and formatted version as soon as it is available. Through the
DOI number used in the citation, you will be able to access this document
at each stage of the publication process. Environ Health Perspect
doi:10.1289/ehp.7728 available via http://dx.doi.org/ [Online 24 February
2005]
The full version of this article is available for free in PDF format.
**************^^^^^^^^^^^^^^^^^^^^^^^^^^********** ****************
Roundup Inhibits Steroidogenesis by Disrupting Steroidogenic Acute
Regulatory (StAR) Protein Expression
Lance P. Walsh,1 Chad McCormick,1 Clyde Martin,2 and Douglas M. Stocco1
1Department of Cell Biology and Biochemistry, Texas Tech University Health
Sciences Center, Lubbock, Texas, USA
2Department of Mathematics, Texas Tech University, Lubbock, Texas, USA
* Introduction
* Materials and Methods
* Results
* Discussion
Abstract
Recent reports demonstrate that many currently used pesticides have the
capacity to disrupt reproductive function in animals. Although this
reproductive dysfunction is typically characterized by alterations in serum
steroid hormone levels, disruptions in spermatogenesis, and loss of
fertility, the mechanisms involved in pesticide-induced infertility remain
unclear. Because testicular Leydig cells play a crucial role in male
reproductive function by producing testosterone, we used the mouse MA-10
Leydig tumor cell line to study the molecular events involved in
pesticide-induced alterations in steroid hormone biosynthesis. We
previously showed that the organochlorine insecticide lindane and the
organophosphate insecticide Dimethoate directly inhibit steroidogenesis in
Leydig cells by disrupting expression of the steroidogenic acute regulatory
(StAR) protein. StAR protein mediates the rate-limiting and acutely
regulated step in steroidogenesis, the transfer of cholesterol from the
outer to the inner mitochondrial membrane where the cytochrome P450 side
chain cleavage (P450scc) enzyme initiates the synthesis of all steroid
hormones. In the present study, we screened eight currently used pesticide
formulations for their ability to inhibit steroidogenesis, concentrating on
their effects on StAR expression in MA-10 cells. In addition, we determined
the effects of these compounds on the levels and activities of the P450scc
enzyme (which converts cholesterol to pregnenolone) and the
3ß-hydroxysteroid dehydrogenase (3ß-HSD) enzyme (which converts
pregnenolone to progesterone). Of the pesticides screened, only the
pesticide Roundup inhibited dibutyryl [(Bu)2]cAMP-stimulated progesterone
production in MA-10 cells without causing cellular toxicity. Roundup
inhibited steroidogenesis by disrupting StAR protein expression, further
demonstrating the susceptibility of StAR to environmental pollutants. Key
words: chemical mixtures, cytochrome P450 side chain cleavage,
environmental endocrine disruptor, 3ß-hydroxysteroid dehydrogenase, Leydig
cells, Roundup, steroid hormones, steroidogenesis, steroidogenic acute
regulatory protein. Environ Health Perspect 108:769-776 (2000). [Online 12
July 2000]
http://ehpnet1.niehs.nih.gov/docs/2000/108p769-776walsh/ abstract.html
Address correspondence to D.M. Stocco, Department of Cell Biology and
Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX
79409 USA. Telephone: (806) 743-2505. Fax: (806) 743-2990. E-mail:
We thank D. Alberts for technical assistance.
This work was supported by NIH grant HD17481 to D. Stucco. L. Walsh was
supported by NIH grant T32-HD07271 and a scholarship from the Lubbock
Achievement Awards for College Scientists Chapter.
Received 3 February 2000; accepted 11 April 2000.
Introduction
The biosynthesis of all steroid hormones begins with the cleavage of the
side chain of cholesterol to form pregnenolone. This reaction is catalyzed
by the P450scc component of the cholesterol side chain cleavage enzyme
system (CSCC) located on the matrix side of the inner mitochondrial
membrane (1). Although this constitutes the rate-limiting enzymatic step in
steroidogenesis, the true rate-limiting step is the delivery of cholesterol
to the inner mitochondrial membrane and the P450scc enzyme (2). Because the
aqueous diffusion of cholesterol is extremely slow, cholesterol cannot
readily diffuse to the inner mitochondrial membrane at rates capable of
sustaining physiologically relevant levels of steroid production (3). To
illustrate this point, maximal steroid production can be achieved in the
absence of stimulation by providing steroidogenic cells with water-soluble
cholesterol analogs, which can freely diffuse to the inner mitochondrial
membrane (4). Thus there are mechanisms that mobilize cholesterol from
cellular stores to the mitochondria and which transfer cholesterol from the
outer to the inner mitochondrial membrane.
Although the delivery of cholesterol from cellular stores to the
mitochondria is essential to maintain maximal rates of steroid production,
the intramitochondrial transfer of cholesterol is the key hormonally
regulated step. Using protein synthesis inhibitors such as cycloheximide
and puromycin, investigators have shown that hormone regulated steroid
production requires rapid de novo protein synthesis (5). Furthermore,
cycloheximide treatment, while permitting cholesterol accumulation in the
outer mitochondrial membrane of steroidogenic cells, almost completely
blocks cholesterol movement to the inner mitochondrial membrane (6). Thus,
a hormone-stimulated, rapidly synthesized, cycloheximide-sensitive protein
is required to mediate the rate-limiting step in steroidogenesis, the
intramitochondrial transfer of cholesterol.
Numerous studies have been performed to identify and characterize this
acute regulatory factor. Although several proteins have been proposed as
the acute regulator [reviewed by Stocco and Clark (7)], one of these
candidate proteins was first described and characterized by Orme-Johnson et
al. (8) as a mitochondrial phosphoprotein that is rapidly synthesized in
response to hormone stimulation in rat adrenal cells. Our laboratory has
described a similar protein in mouse MA-10 Leydig tumor cells and has since
purified, cloned, sequenced, and expressed this protein and named it the
steroidogenic acute regulatory (StAR) protein. The StAR protein fulfills
all of the criteria of the putative acute regulatory factor (7,9,10).
Perhaps the most compelling argument for the role of StAR in
steroidogenesis comes from the finding that, in humans, mutations in the
StAR gene cause the disease lipoid congenital adrenal hyperplasia (lipoid
CAH), a condition in which cholesterol and cholesterol esters accumulate
and the newborn is unable to synthesize adequate levels of steroid
hormones. Furthermore, StAR knockout mice have been generated, and their
phenotype mirrors that of human lipoid CAH (11). These observations
indicate that StAR plays an indispensable role in the transfer of
cholesterol to the P450scc.
Because StAR protein mediates the rate-limiting step in steroidogenesis, we
hypothesized that, when compared to the steroidogenic enzymes, StAR protein
may be particularly susceptible to modulation by environmental pollutants
for a number of reasons. First, unlike the steroidogenic enzymes that are
chronically regulated and have long half-lives (12), StAR protein is not an
enzyme, is acutely regulated, and its active precursor form is highly
labile. Second, StAR protein expression is critically dependent on trophic
hormone stimulation, making it susceptible to xenobiotics that disrupt
components of the trophic hormone signaling pathway. In contrast, with the
exception of cytochrome P450 17alpha-hydroxylase/17,20-lyase (P450c17), the
steroidogenic enzymes retain near-normal steroidogenic enzyme capacity even
in the absence of trophic hormone stimulation (12). Third, StAR mediates
the rate-limiting step in steroidogenesis, rendering steroidogenesis
extremely sensitive to disruptions in its expression. Conversely, with the
exception of P450scc, which can be limiting, the steroidogenic enzymes are
present in excess amounts (13). Fourth, because StAR functions upstream of
steroidogenic enzyme activity, the effects of the xenobiotic on
steroidogenic enzyme activity may be of little importance if the xenobiotic
also blocks StAR protein expression. Finally, we recently showed that two
pesticides, the organochlorine insecticide lindane (Sigma, St. Louis, MO),
and the organophosphate insecticide Dimethoate (BASF Corp., Agricultural
Products Group, Research Triangle Park, NC), both of which lower serum
testosterone levels in animals, block steroid hormone biosynthesis in
Leydig cells by reducing StAR protein expression (14,15). These findings
raise the possibility that other pesticides may also inhibit
steroidogenesis by targeting StAR expression.
Several currently used pesticides disrupt steroid hormone levels and/or
reproductive system function in animals (16-19). One billion pounds of
active ingredients and several times this amount of inert ingredients are
used annually in the United States alone; therefore, the possibility that
these compounds can affect the reproductive health of humans and wildlife
in their natural habitats is of great concern (20). Little information is
available regarding the effects of pesticides, including Ammo (Zeneca
Agricultural Products, Wilmington, DE) and Ambush (Zeneca Agricultural
Products) and the herbicides Banvel (Sanex, Inc., Burlington, Ontario,
Canada), Cotoran (Ciba-Geigy Corporation, Greensboro, NC), Cyclone (Zeneca
Agricultural Products), Fusilade (Zeneca Agricultural Products), Dual
(Ciba-Geigy), and Roundup (Monsanto Co., St. Louis, MO) on endocrine system
function, despite their widespread use. Therefore, the present study was
performed to determine if these pesticides can disrupt steroid hormone
biosynthesis in the mouse MA-10 Leydig tumor cell line and to determine the
site of steroidogenic inhibition.
Damage
http://www.organicconsumers.org/monsanto/fetal030105.cfm
Posted 3/1/05
PRESS RELEASE
Pr. Gilles-Eric SERALINI's group in the University of Caen (Normandy,
France) just published original results concerning the toxicity of
Roundup. Il is one of the most used herbicides worldwide and the most
used with genetically modified plants (GMOs).
The majority of GMOs commercialized in the world are designed for food
and feed. These plants have been modified to remain alive after
herbicide absorption, this herbicide being spread on the cultures.
This greatly facilitates its use, as well as the presence of its
residues in the food chain. It is also evoked as a common pollutant in
rivers.
It is shown in this work that human placental cells are very sensitive
to Roundup, to concentrations lower than the agricultural use. This
could explain miscarriages and premature births in the United States in
farmers. Moreover, below toxic levels, the effects of Roundup are
measured on the synthesis of sexual hormones; this allow to classify
this herbicide in potential endocrine disruptors. Finally, the effects
of Roundup are always greater than those of glyphosate, which is known
as its active compound.
This work was supported in particular by CRIIGEN (www.crii-gen.org
http://www.crii-gen.org/
and by The "Fondation pour une Terre Humaine"
Contact : Pr. Gilles-Eric SERALINI, tel. 33 2 31 56 54 89,
>
Environmental health perspective
Differential effects of glyphosate and Roundup
on human placental cells and aromatase
Sophie Richard, Safa Moslemi, Herbert Sipahutar, Nora
Benachour, Gilles-Eric Seralini
doi:10.1289/ehp.7728 (available at http://dx.doi.org/)
Online 24 February 2005
Abstract Roundup is a glyphosate-based herbicide used worldwide including
on most
genetically modified plants in which it can be tolerated. Its residues may
thus enter the
food chain and glyphosate is found as a contaminant in rivers. Some
agricultural workers using
glyphosate have pregnancy problems, but its mechanism of action in mammals
is questioned. Here we
show that glyphosate is toxic on human placental JEG3 cells within 18 hr
with concentrations
lower than the agricultural use, and this effect increases with
concentration and time,
or in the presence of Roundup adjuvants. Surprisingly, Roundup is always
more toxic than its
active ingredient. We tested its effect on aromatase with lower non-toxic
concentrations, the
enzyme responsible for estrogen synthesis. The herbicide acts as an
endocrine disruptor on
aromatase activity and mRNA levels, and glyphosate interacts within the
active site of the purified
enzyme, but its effect is facilitated by Roundup formulation in microsomes
or in cell culture. We
conclude that endocrine and toxic effects of Roundup and not only
glyphosate can be observed in
mammals. We suggest that the presence of Roundup adjuvants enhances
glyphosate
bioavailability and / or bioaccumulation.
************************************************** **************************
This GMO news service is underwritten by a generous grant from the Newman's
Own Foundation, edited by Thomas Wittman and is a production of the
Ecological Farming Association www.eco-farm.org <http://www.eco-farm.org/
************************************************** **************************
Research Article
Differential effects of glyphosate and Roundup on human placental cells
and aromatase
Sophie Richard, Safa Moslemi, Herbert Sipahutar, Nora Benachour,
Gilles-Eric Seralini
http://ehp.niehs.nih.gov/docs/2005/7728/abstract.html
Abstract in PDF
This EHP-in-Press article has been peer-reviewed, revised, and accepted for
publication. The EHP-in-Press articles are completely citable using the
assigned DOI code for the article. This document will be replaced with the
copyedited and formatted version as soon as it is available. Through the
DOI number used in the citation, you will be able to access this document
at each stage of the publication process. Environ Health Perspect
doi:10.1289/ehp.7728 available via http://dx.doi.org/ [Online 24 February
2005]
The full version of this article is available for free in PDF format.
**************^^^^^^^^^^^^^^^^^^^^^^^^^^********** ****************
Roundup Inhibits Steroidogenesis by Disrupting Steroidogenic Acute
Regulatory (StAR) Protein Expression
Lance P. Walsh,1 Chad McCormick,1 Clyde Martin,2 and Douglas M. Stocco1
1Department of Cell Biology and Biochemistry, Texas Tech University Health
Sciences Center, Lubbock, Texas, USA
2Department of Mathematics, Texas Tech University, Lubbock, Texas, USA
* Introduction
* Materials and Methods
* Results
* Discussion
Abstract
Recent reports demonstrate that many currently used pesticides have the
capacity to disrupt reproductive function in animals. Although this
reproductive dysfunction is typically characterized by alterations in serum
steroid hormone levels, disruptions in spermatogenesis, and loss of
fertility, the mechanisms involved in pesticide-induced infertility remain
unclear. Because testicular Leydig cells play a crucial role in male
reproductive function by producing testosterone, we used the mouse MA-10
Leydig tumor cell line to study the molecular events involved in
pesticide-induced alterations in steroid hormone biosynthesis. We
previously showed that the organochlorine insecticide lindane and the
organophosphate insecticide Dimethoate directly inhibit steroidogenesis in
Leydig cells by disrupting expression of the steroidogenic acute regulatory
(StAR) protein. StAR protein mediates the rate-limiting and acutely
regulated step in steroidogenesis, the transfer of cholesterol from the
outer to the inner mitochondrial membrane where the cytochrome P450 side
chain cleavage (P450scc) enzyme initiates the synthesis of all steroid
hormones. In the present study, we screened eight currently used pesticide
formulations for their ability to inhibit steroidogenesis, concentrating on
their effects on StAR expression in MA-10 cells. In addition, we determined
the effects of these compounds on the levels and activities of the P450scc
enzyme (which converts cholesterol to pregnenolone) and the
3ß-hydroxysteroid dehydrogenase (3ß-HSD) enzyme (which converts
pregnenolone to progesterone). Of the pesticides screened, only the
pesticide Roundup inhibited dibutyryl [(Bu)2]cAMP-stimulated progesterone
production in MA-10 cells without causing cellular toxicity. Roundup
inhibited steroidogenesis by disrupting StAR protein expression, further
demonstrating the susceptibility of StAR to environmental pollutants. Key
words: chemical mixtures, cytochrome P450 side chain cleavage,
environmental endocrine disruptor, 3ß-hydroxysteroid dehydrogenase, Leydig
cells, Roundup, steroid hormones, steroidogenesis, steroidogenic acute
regulatory protein. Environ Health Perspect 108:769-776 (2000). [Online 12
July 2000]
http://ehpnet1.niehs.nih.gov/docs/2000/108p769-776walsh/ abstract.html
Address correspondence to D.M. Stocco, Department of Cell Biology and
Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX
79409 USA. Telephone: (806) 743-2505. Fax: (806) 743-2990. E-mail:
We thank D. Alberts for technical assistance.
This work was supported by NIH grant HD17481 to D. Stucco. L. Walsh was
supported by NIH grant T32-HD07271 and a scholarship from the Lubbock
Achievement Awards for College Scientists Chapter.
Received 3 February 2000; accepted 11 April 2000.
Introduction
The biosynthesis of all steroid hormones begins with the cleavage of the
side chain of cholesterol to form pregnenolone. This reaction is catalyzed
by the P450scc component of the cholesterol side chain cleavage enzyme
system (CSCC) located on the matrix side of the inner mitochondrial
membrane (1). Although this constitutes the rate-limiting enzymatic step in
steroidogenesis, the true rate-limiting step is the delivery of cholesterol
to the inner mitochondrial membrane and the P450scc enzyme (2). Because the
aqueous diffusion of cholesterol is extremely slow, cholesterol cannot
readily diffuse to the inner mitochondrial membrane at rates capable of
sustaining physiologically relevant levels of steroid production (3). To
illustrate this point, maximal steroid production can be achieved in the
absence of stimulation by providing steroidogenic cells with water-soluble
cholesterol analogs, which can freely diffuse to the inner mitochondrial
membrane (4). Thus there are mechanisms that mobilize cholesterol from
cellular stores to the mitochondria and which transfer cholesterol from the
outer to the inner mitochondrial membrane.
Although the delivery of cholesterol from cellular stores to the
mitochondria is essential to maintain maximal rates of steroid production,
the intramitochondrial transfer of cholesterol is the key hormonally
regulated step. Using protein synthesis inhibitors such as cycloheximide
and puromycin, investigators have shown that hormone regulated steroid
production requires rapid de novo protein synthesis (5). Furthermore,
cycloheximide treatment, while permitting cholesterol accumulation in the
outer mitochondrial membrane of steroidogenic cells, almost completely
blocks cholesterol movement to the inner mitochondrial membrane (6). Thus,
a hormone-stimulated, rapidly synthesized, cycloheximide-sensitive protein
is required to mediate the rate-limiting step in steroidogenesis, the
intramitochondrial transfer of cholesterol.
Numerous studies have been performed to identify and characterize this
acute regulatory factor. Although several proteins have been proposed as
the acute regulator [reviewed by Stocco and Clark (7)], one of these
candidate proteins was first described and characterized by Orme-Johnson et
al. (8) as a mitochondrial phosphoprotein that is rapidly synthesized in
response to hormone stimulation in rat adrenal cells. Our laboratory has
described a similar protein in mouse MA-10 Leydig tumor cells and has since
purified, cloned, sequenced, and expressed this protein and named it the
steroidogenic acute regulatory (StAR) protein. The StAR protein fulfills
all of the criteria of the putative acute regulatory factor (7,9,10).
Perhaps the most compelling argument for the role of StAR in
steroidogenesis comes from the finding that, in humans, mutations in the
StAR gene cause the disease lipoid congenital adrenal hyperplasia (lipoid
CAH), a condition in which cholesterol and cholesterol esters accumulate
and the newborn is unable to synthesize adequate levels of steroid
hormones. Furthermore, StAR knockout mice have been generated, and their
phenotype mirrors that of human lipoid CAH (11). These observations
indicate that StAR plays an indispensable role in the transfer of
cholesterol to the P450scc.
Because StAR protein mediates the rate-limiting step in steroidogenesis, we
hypothesized that, when compared to the steroidogenic enzymes, StAR protein
may be particularly susceptible to modulation by environmental pollutants
for a number of reasons. First, unlike the steroidogenic enzymes that are
chronically regulated and have long half-lives (12), StAR protein is not an
enzyme, is acutely regulated, and its active precursor form is highly
labile. Second, StAR protein expression is critically dependent on trophic
hormone stimulation, making it susceptible to xenobiotics that disrupt
components of the trophic hormone signaling pathway. In contrast, with the
exception of cytochrome P450 17alpha-hydroxylase/17,20-lyase (P450c17), the
steroidogenic enzymes retain near-normal steroidogenic enzyme capacity even
in the absence of trophic hormone stimulation (12). Third, StAR mediates
the rate-limiting step in steroidogenesis, rendering steroidogenesis
extremely sensitive to disruptions in its expression. Conversely, with the
exception of P450scc, which can be limiting, the steroidogenic enzymes are
present in excess amounts (13). Fourth, because StAR functions upstream of
steroidogenic enzyme activity, the effects of the xenobiotic on
steroidogenic enzyme activity may be of little importance if the xenobiotic
also blocks StAR protein expression. Finally, we recently showed that two
pesticides, the organochlorine insecticide lindane (Sigma, St. Louis, MO),
and the organophosphate insecticide Dimethoate (BASF Corp., Agricultural
Products Group, Research Triangle Park, NC), both of which lower serum
testosterone levels in animals, block steroid hormone biosynthesis in
Leydig cells by reducing StAR protein expression (14,15). These findings
raise the possibility that other pesticides may also inhibit
steroidogenesis by targeting StAR expression.
Several currently used pesticides disrupt steroid hormone levels and/or
reproductive system function in animals (16-19). One billion pounds of
active ingredients and several times this amount of inert ingredients are
used annually in the United States alone; therefore, the possibility that
these compounds can affect the reproductive health of humans and wildlife
in their natural habitats is of great concern (20). Little information is
available regarding the effects of pesticides, including Ammo (Zeneca
Agricultural Products, Wilmington, DE) and Ambush (Zeneca Agricultural
Products) and the herbicides Banvel (Sanex, Inc., Burlington, Ontario,
Canada), Cotoran (Ciba-Geigy Corporation, Greensboro, NC), Cyclone (Zeneca
Agricultural Products), Fusilade (Zeneca Agricultural Products), Dual
(Ciba-Geigy), and Roundup (Monsanto Co., St. Louis, MO) on endocrine system
function, despite their widespread use. Therefore, the present study was
performed to determine if these pesticides can disrupt steroid hormone
biosynthesis in the mouse MA-10 Leydig tumor cell line and to determine the
site of steroidogenic inhibition.