ISSN 10227954, Russian Journal of Genetics, 2011, Vol. 47, No. 2, pp. 221–225. © Pleiades Publishing, Inc., 2011.
Original Russian Text © E.A. Zarubina (Dubovenko), L.V. Osadchuk, 2011, published in Genetika, 2011, Vol. 47, No. 2, pp. 249–254.
The testosterone contents of the blood and gonads
are reliable indices of the hormonal activity of testes in
a male body. Testosterone is involved in the formation
of the male phenotype and maintenance of the repro
ductive function in male mammals. The hormone is
synthesized by Leydig cells of the testes, its production
being controlled by pituitary luteinizing hormone
Chorionic gonadotropin (CG), which is produced
by the placenta during pregnancy, is a functional ana
log of LH. This is a glycoprotein hormone a molecule
of which consists of two noncovalently bound subunits
CG subunit is identical to the
subunit of LH, folliclestimulating hormone, and
thyrotropic hormone. The
CG subunit is specific for
CG; however, it is highly (about 80%) homologous to
subunit of LH. The CG molecules of humans
and many other species are considerably homologous
to one another .
There are LH/CG receptors (LHCGRs) on the
surface of Leydig cells. LHCGR activation leads to
testosterone release by Leydig cells via activation of
the cAMP pathway, causing an increase in the produc
tion of steroidogenesis enzymes .
CG is widely used in medicine and agriculture for
stimulation of the testicular function. Preparations of
CG are prescribed to men with spermatogenesis disor
ders and deficiency of androgens or gonadotropic hor
mones of various etiologies [4–8]. CG is used for stim
ulation of testicular steroidogenesis and spermatogen
esis in domestic animals, including cattle, and in
breeding fur animals, fish, and amphibians in captivity
An individual pharmacological response to a phar
maceutical drug is known to depend on many factors,
such as sex, age, concomitant diseases, simultaneously
administered drugs, diet, unhealthy behaviors, etc.
The genetic potential (hereditary differences in the
response to drugs) is another important factor affect
ing drug efficacy . However, the genetic predispo
sition to a specific response to individual drugs
remains the main, and largely unexplored, problem of
Inbred mouse strains are suitable models for study
ing genetic differences in the responses to drugs. In
particular, the genetic variation of the testicular hor
monal responsiveness to the stimulation of the testic
ular function with CG remains poorly understood.
Pharmacological studies using a wide range of inbred
mouse strains allows the genetic differences in the
effects of drugs to be imitated.
Osadchuk and Svechnikov  demonstrated dif
ferences between six inbred mouse strains in the test
osterone production by unstimulated and CGstimu
lated isolated Leydig cells in vitro. However, the results
obtained in vitro require further testing in vivo, which
would give an idea about the genetic differences in tes
ticular responsiveness to CG under the influence of al
regulatory mechanisms of the hypothalamic–pitu
The purpose of this study was to determine the
genetic differences in the hormonal testicular respon
Phenogenetic Analysis of Testicular Responsiveness to Chorionic
Gonadotropin in Inbred Mouse Strains
E. A. Zarubina (Dubovenko) and L. V. Osadchuk
Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090 Russia;
Received May 19, 2010
—Genetic differences in the testicular hormonal responsiveness to in vivo administration of chori
onic gonadotropin (CG) between adult male mice of eight inbred strains (A/Sn, CBA/Lac, CC57Br,
C57Bl/6J, DBA/2J, GR, PT, and YT) were determined. In addition, the genetic variation of the body and
testis weights was estimated as related to the responsiveness to stimulation of steroidogenesis with CG. Adult
males were subcutaneously injected with 10 IU of CG or physiological saline 120 min before decapitation. It
was found that the baseline testosterone level in the blood serum and its content in the testes only slightly var
ied in males of the strains studied. Administration of CG increased these parameters by a factor of 3–45,
depending on the strain. The results of the study indicate genetic differences in the testicular reactivity to CG.
In addition, it has been found that the response to administration of CG, as compared to the baseline levels,
provides the most reliable information on the genetic characteristics of the hormonal potential of the testes.
The given set of inbred mouse strains may be a promising genetic model for studying the physiological and
hereditary variations of testicular steroidogenesis.