Low Doses of Gamma Radiation may Impair Testicular Tissue in a Rat Treated CCl4 Model: Role of BM Transplantation
Treatment of carbon tetrachloride (CCl4) 1 mL kg-1 in olive oil (1:1) twice a week for 8 weeks to albino male rat caused a significant increase in serum level of alanine transaminase (ALT) and aspartate transaminase (AST). Injury to liver, resulting in loss of its normal physiological/biochemical functions, may adversely affect a secondary organ like testis. In the current study young adult rats were treated by Carbon tetrachloride (CCl4) two times per week and/or continuously whole body γ-irradiated (R) at a dose level 0.5 Gy, two times per week for 8 weeks. The previous groups were treated by bone marrow transplantation (BMT). Plasma estradiol and testosterone concentrations in animals sera were analyzed. Histopathological, apoptosis and necrosis examinations were done in testicular tissues. Either CCl4 or R exposure alone or combined reflect testicular seminiferous tubules atrophy, peritubular fibrosis and apoptotic cells in seminiferous epithelium and Leydig cells. BMT reflect some recurrence of normal structure in testis tissue of CCl4 group. Meanwhile R and CCl4 R groups showed atrophied testicular seminiferous tubules, great interstitial hyperplasia, deposition of collagen fibres around blood vessels and presence of interstitial apoptotic and necrotic tissue cells. CCl4 treatment recorded anon significant change in plasma testosterone and a significant decrease in estradiol concentration. γ-irradiation either alone or combined with CCl4 treatments recorded a significant reduction in testosterone level and significant increase in estradiol concentration. BMT recorded a significant increase in testosterone level and anon significant change in estradiol level following CCl4 or irradiation either alone or combined. In conclusion low doses of γ- radiation impair testicular tissue in a rat treated CCl4 model. BM transplantation recorded increase in this testicular damage.
Received: November 04, 2011;
Accepted: February 15, 2012;
Published: June 12, 2012
Carbon tetrachloride is used extensively in experimental models to induce oxidative
stress in rats (Onori et al., 2000; Nabeshima
et al., 2006; Noori et al., 2009).
A single dose of CCl4 can rapidly lead to both oxidative stress and
acute liver injuries such as centrilobular necrosis and steatosis in rats (Weber
et al., 2003; Lin et al., 2008; Khan
and Alzohairy, 2011). Previous data demonstrated that rats with advanced
liver cirrhosis showed reduced testicular size and weight and severe histopathological
testicular abnormalities, including reduced tubular diameters, loss of the germinal
line and diminutions in cellular proliferation and spermatogenesis (Castilla-Cortazar
et al., 2000). Also previous data demonstrated that rats treated
by CCl4 showed histopathological testicular abnormalities and loss
of the germinal line (Khan and Ahmed, 2009).
The biological effects of low-level radiation have attracted the attention
of investigators for more than 20 years. The biological effects of low-level
radiation on cellular metabolisms and defence systems sometimes called hormesis
(Feinendegen, 2005) by increased immune responses and
antioxidant capacity (Lee et al., 2000; Gong
et al., 2000; Joksic and Petrovic, 2004).
However, Liu et al. (2006) reported that the
exposure of the experimental animals to low-level radiation induces increased
apoptosis in male germ cells. Bone marrow transplantation (BMT) is increasingly
used in the therapy of solid malignancies, as well as in non-malignant disorders
such as thalassemia and immunodeficiency (OReilly,
1983; Champlin and Gale, 1987). Also the preclinical
and clinical studies have demonstrated that bone marrow stromal cells (MSCs)
can be used for tissue repair (Yoon et al., 2005).
The successful application of Bone Marrow Transplantation BMT to the treatment
of several potentially fatal disorders (Storb et al.,
1976; Powles et al., 1980; Oleary
et al., 1983) has resulted in a variety of late complications on
gonadal function and future fertility.
The present study was done to recognize the effect of exposure to low dose of γ-radiation on testis tissue in rat treated CCl4 model and the role of BM transplantation.
MATERIALS AND METHODS
Experimental animals: Male Swiss albino rats (100-120 g) purchased from the Egyptian Organization for Biological Products and Vaccines were used for the different investigations carried out in this work. Animal maintenance and treatments were conducted in accordance with the National Institute of Health Guide for Animal, as approved by Institutional Animal Care and Use Committee (IACUC). Animals were housed in specially designed cages and maintained in conditions of good ventilation, normal temperatures and humidity ranges and kept under observation for one week prior to experimentation. The rats were fed on standard pellets, containing all nutritive elements (proteins, fats, carbohydrates, vitamins, salts and minerals). Drinking water and food were provided ad libitum throughout the study.
Radiation facility: Whole-body γ-irradiation was performed at the National Centre for Radiation Research and Technology (NCRRT), Cairo, Egypt, using an AECL Gamma Cell-40 biological irradiator. Animals were irradiated at dose level of 0.5 Gy 2 times/week for 8 weeks. The γ-irradiation delivered at a dose rate of 0.46 Gy/min.
Rat bone marrow preparation: Donors and recipients rats were chosen of the same inbred strain, brother to brother (isologues or synergic or allogeneic transplantation). Rats sacrificed by exposure to ether in a dessicator kept in a well-functioning hood. Femur bones were dissected out and cleaned. The ends of the bones were chipped by a bone nibbling forceps. Then the marrow was blown out of the femur into isotonic solution under sterilized conditions inside a laminar flow cabinet. The marrow was collected into a sterile container surrounded by ice cubes and mixed by drawing and expelling it several times from the syringe without needle in order to avoid mechanical damage to the cells. Total viable cells of about 75x106±5% were injected intravenously (IV) through the caudal vein. All Rats treated with bone marrow cells transplantation were killed after four weeks of bone marrow cells transplantation.
Carbon tetrachloride administration: Rats were intraperitoneally injected with 1 mL kg-1 of carbon tetrachloride (CCl4) dissolved in olive oil (1:1) twice a week for 8 weeks.
Experimental design: A total of 48 rats were divided into the following sub groups.
Non Bone marrow administrated groups including:
||Control group (C): untreated normal rats
||Irradiated group (R): group of animals exposed to 0.5 Gy of γ-
radiation two times/week for 8 weeks
||Carbon tetrachloride administrated group (CCl4): group
of animals treated by CCl4 twice a week for 8 weeks
||Irradiated and carbon tetrachloride treated group (CCl4
R): group of animals exposed to 0.5 Gy of γ- radiation 2 times/week
and treated by CCl4 twice a week for 8 weeks
Bone marrow administrated groups including:
||Bone marrow treated group (BM): group of control animals
treated with bone marrow cells transplantation and killed after four weeks
of bone marrow cells transplantation
||Irradiated bone marrow transplantation group (RBM): group of animals
irradiated for 4 weeks then treated with bone marrow cells transplantation
followed by exposure to γ-radiation for another 4 weeks
||CCl4 bone marrow transplantation group (CCl4
BM): group of animals treated by CCl4 for four weeks and
then treated with bone marrow cells transplantation followed by the same
dose of CCl4 treatment for another four weeks
||CCl4 R bone marrow transplantation group (CCl4
RBM): group of animals treated by CCl4, exposed to γ-radiation
for 4 weeks then treated with bone marrow cells transplantation followed
by the same dose of CCL4 and γ-radiation exposure treatments
for another four weeks
Histopathological examination: Excised liver and testis tissues from each rat were fixed in 100 mL L-1 neutral formalin, embedded in paraffin and stained with hematoxylin-eosin (HE) and the fibrous lesion areas were determined via Masson's trichrome method which is used to stain collagen fibers.
Apoptosis and necrosis examination: For apoptosis and necrosis examination
according to Bank (1988) fluorescence microscopy was
used. Deparaffinization was done by immersing tissue sample slides in 3 changes
of xylene for 5 min each followed by washing in graded alcohol as follows: 100,
95, 80 and 50% for re-hydration. Two changes for 3 min in each alcohol concentration
were done. Then, they were rinsed in 3 changes of PBS. Afterwards, slides were
directly incubated in (5 μg mL-1 of propidium iodide and 50
μg mL-1 of acridine orange in phosphate-buffered saline) in
dark for 20 min at room temperature.
Analysis of biochemical assay: Serum obtained from the blood samples
were analyzed for aspartate aminotransferase (AST) (Bergmeyer
et al., 1985), alanine aminotrasnferase (ALT) (Klauke
et al., 1993) and total protein (Keller, 1984)
by using kit purchased from Stanbio (USA). However, serum testosterone and estradiol
ware quantitatively determined in the sera by enzyme immunoassay kit (Meddix
Bioech Inc, 420 Lincoln Centre Drive, Foster City, CA 94404, USA, Catalog Number:
Statistical analysis: Statistical analysis for obtained results was carried out with the aid of the SPSS computer software program.
OBSERVATIONS AND RESULTS
At baseline, in Table 1 compared to control level (p<0.05) CCl4 treated group showed a significant increase in serum ALT and AST levels but total proteins represented, no significant change. Exposure of control rats to fractionated low dose of γ-radiation recorded a no significant change in serum ALT and AST levels but total proteins represented, a significant increase compared to control level (p<0.05). On the other hand exposure of CCl4 treated group to fractionated low dose of γ-radiation recorded a decrease in serum levels of ALT, AST but total proteins level recorded a significant increase in compression to CCl4 group level (p<0.05). Bone marrow transplantation in control animals represented a significant decrease in serum ALT, a significant increase in serum AST and no significant change in total proteins. However, BM transplantation in CCL4 or CCl4 R groups showed ameliorating effect in AST, ALT and total proteins levels compared to CCl4 treated group.
Histopathologically liver tissue sections in rats suffered from CCl4
treatment (two times per week) for eight weeks showed hepatocytes degeneration,
necrosis, mononuclear cells and neutrophil infiltration. Also, collagen fibers
extend within the hepatic plate was observed. Bone marrow cells transplantation
showed normal hepatic tissue section. Exposure of the CCl4 treated
group to 0.5 Gy (two times per week) for eight weeks showed some sort of regeneration
in a considerable number of hepatocytes, inhibition of inflammatory cellular
infiltration in many areas and less prominent of cytoplasmic vacuolation.
||Effect of CCl4, radiation and BM either alone or
combined on liver functions
|Values are given as mean ±SD (n = 6), *Significantly
different from control at 0.05, #Significantly different from
CCl4 treatment at 0.05
On the other hand liver section in CCl4 (two times per week for
eight weeks) rats irradiated with 0.5 Gy and treated with bone marrow cells
(one time at the fourth week) transplantation recorded that bone marrow cells
helped very much in regain of most hepatocytes cellular structure. There are
no signs of cell weakness as many hepatocytes appeared with well defined membranes,
homogenous cytoplasm and healthy normal nuclei. Many mitotic figures were noted,
blood sinusoids were normal in size and the blood vessel was well organized.
TESTICULAR TISSUE OBSERVATIONS
H and E stain: In Fig. 1 the light microscopic examination
of the testis of control rats showed normal structure and completely enveloped
by a thick capsule, tunica albuginea which is composed mainly of dense collagenous
fibrous connective tissue. The structural components of the testis are the seminiferous
tubules and interstitial tissues. The seminiferous tubules are two types of
cells, the Sertoli cells, resting on the thin basal lamina (basement membrane)
and the spermatogenic cells. These cells are many layers, namely, the spermatogonia,
primary and secondary spermatocytes; spermatoids and finally mature spermatozoa.
Treatment of the experimental animals by CCl4 (two times per week)
for eight weeks noted wide interstitial space, seminiferous tubuli in testis
appear seriously damaged and animals show a decrease of tubular diameter, vacuolization
on germinal epithelium, loss of germinal line, total or partial reduction of
spermatogenesis and presence of abnormal spermatids (multinucleated cells and
cells with an intense stained nuclei). Exposure of control rats to 0.5 Gy (two
times per week) for eight week showed atrophy and decrease in size of seminiferous
tubule, tubular profiles completely depleted of germ cells and some hyperplasia
in the Leydig cell was observed. Increase in testicular disorganization was
detected in seminiferous tubules when CCl4 (two times per week for
eight weeks) treated animals exposed to 0.5 Gy γ-radiations (two times
per week for eight weeks).
||Microscopy of testes (×400 magnifications, H&E stain).
Testicular histological sections of rat demonstrated active spermatogenesis
in normal-size seminiferous tubuli with thin basement membranes (▲).
Leydig cells were scarce, being widely separated by seminiferous tubuli.
BM represented discontinuous seminiferous epithelium (short arrow). Either
CCL4 or R exposure alone or combined reflect testicular seminiferous
tubules atrophy and completely depleted of germ cells ().
BM treatment of CCL4 group reflects great recurrence of seminiferous
tubules normal structure in testes. Exudation (E) into the interstitial
space and degeneration/necrosis (N) of spermatogenic and great interstitial
hyperplasia (long arrow) in R+BM and CCL4+R+BM groups
|| Effect of CCl4, radiation and BM either alone
or combined on testosterone and estradiol testicular hormones
|Each value represents the mean of 6 records±SE. Means
with different superscripts are significantly different at the 0.05 level.*
significatly different from control, #significantly different from CCl4.
! significantly different from CCl4+BM and R+BM
Seminiferous tubules in testis appear seriously damaged, decrease in tubular
diameter, vacuolization on germinal epithelium, loss of germinal line, total
reduction of spermatogenesis and increase in hyperplasia in the Leydig cell
Treatment of control group with BM cells represented discontinuous seminiferous epithelium. Great recurrence of seminiferous tubules normal structure in testis when experimental animals treated by CCl4 (two times per week) for eight weeks and treated by bone marrow cells transplantation (one time at the fourth week) was occurred. Exudation into the interstitial space and degeneration/necrosis of spermatogenic cells were observed when rats irradiated for four weeks and then bone marrow cells transplantation occurred followed by irradiation again for another four weeks. Atrophied testicular seminiferous tubules and great interstitial hyperplasia were shown in testis of CCl4 irradiated rats for four weeks, followed by bone marrow cells transplantation one time and continue the process of irradiation and CCl4 treatments for another four weeks.
Masson's trichrome stain: In Fig. 2 treatment of the experimental animals with CCl4 or low dose of γ- radiation exposure either alone or combined represented peritubular fibrosis or increase in collagen deposition. Treatment of the previous groups with BM represents a remarkable depletion in peritubular collagen deposition with its great deposition on blood vessels sides.
Apoptosis and necrosis observations: In Fig. 3 testicular sections of normal rat (Control) demonstrated anon apoptotic observations in seminiferous epithelium. CCl4 treatment (two times per week for eight weeks) recorded the presence of apoptotic cells in seminiferous epithelium. Both 0.5 Gy of γ-radiation exposure (two times per week for eight weeks) or CCl4 and 0.5 Gy irradiation (two times per week for eight weeks) treatments represented apoptosis in the Leydig cells. BM cells transplantation showed many apoptotic observations in the spermatogonia, sertoli cells and primary spermatocytes. Interstitial tissue represented necrotic observations. Treatment of CCl4 group by BM cells transplantation recorded apoptotic and necrotic cells. Also treatment of irradiated animals either alone or combined with CCl4 treatments by BM cells transplantation represented many interstitial apoptotic and necrotic tissue cells.
Analysis of testosterone and estradiol testicular hormones: In Table 2 testicular hormonal analysis of testosterone concentration was investigated in this study. A non-significant reductions in testosterone concentration mean values when compared with the control concentration (p<0.05) following CCl4 treatment (two times per week for eight weeks). However, exposure of control rats to fractionated dose of γ-radiation (0.5 Gy two times per week for eight weeks) recorded a significant reduction in testosterone concentration level when compared with the control level (p<0.05). Combined treatment of the experimental animals by CCl4 and γ-irradiation recorded a significant decrease in testosterone level compared to control or irradiated group. BM cells transplantation in rats empire their testosterone level either alone or following CCl4 or γ-radiation exposure registered a significant decrease comparing to control level.
Also Table 2 represented Estradiol levels in different studied groups. Estradiol levels showed a significant decrease for the treatment of the experimental rats by CCl4. Meanwhile radiation exposure represented a significant increase in compression to control level. Combined treatment of CCl4 and fractionated dose of γ-irradiation (0.5 Gy two times per week for eight weeks) recorded a significant increase in estradiol level compared to control or irradiated group levels. On the other hand BM cells transplantation in experimental rats recorded a non- significant change in estradiol level when compared with the control level (p<0.05) following CCl4 treatment or radiation exposure.
The present study was designed in order to gain more insights into the effect of exposure to consecutive low dose of γ-radiation and bone marrow transplantation were evaluated in CCl4 treated rats and the altered changes in testis tissue associated with liver disease.
Our study demonstrates that rats treated by CCl4-induced many histopathological
and biochemical altered changes in liver tissue show a severe testicular atrophy
and gonadal insufficiency. Both testicular histopathological abnormalities and
low levels of sex hormones have been described in previous years in patients
with alcoholic and nonalcoholic cirrhosis (Pajarinen and
Karhunden, 1994; Van Steenbergen, 1993).
||Microscopy of testes (x400 magnifications, Massons stain).
Testicular histological sections of normal rat (Control) demonstrated minimal
peritubular fibrosis. Evidence of peritubular fibrosis and other alterations
were found in testes from R, CCl4 and CCl4+R treated
animals. Treatment with BM recorded great deposition of collagen fibres
(↑) around blood vessels.
Our data show a severe testicular damage as manifested by a variety of histopathological
abnormalities that include alterations in tubular diameters, presence of aberrant
cells in tubular lumen, peritubular fibrosis, loss of the germinal line and
the presence of apoptotic cells in seminiferous epithelium. These alterations
resemble those reported in experimental models of testicular damage, such as
chronic testicular ischemia (Santamaria et al., 1995;
Al-Jahdali and Bisher, 2007).
||Fluorescent Microscopy of testes (x400 magnifications, propidium
iodide/acridine orange stain). Testicular sections of normal rat (Control)
demonstrated anon apoptotic observations in seminiferous epithelium. CCL4
treatment recorded the presence of apoptotic cells in seminiferous epithelium
(↑). Either Radiation exposure or CCL4 and irradiation treatments
represented apoptosis in the Leydig cells (↑). BM transplantation showed
many apoptotic observations in the spermatogonia, sortoli cells and primary
spermatocytes. Interstitial tissue represented necrotic observations. CCL4BM
treatment recorded apoptotic (↑) and necrotic cells ().
Treatment of irradiated animals by BM represented many interstitial apoptotic
and necrotic tissue cells. Treatment of CCL4 and irradiated group
by BM also represented interstitial apoptotic (↑) and necrotic tissue
The occurrence of testicular atrophy and gonadal dysfunction in advanced cirrhosis
is a well-known clinical event (Van Thiel et al.,
1980; Bannister et al., 1986; Pajarinen
and Karhunden, 1994).
Ranl et al. (2007) proposed that the cause of
testicular histopathology may be attributed to the malfunctioning of liver (Lox,
1984) which causes general systemic toxicity due to some toxic factors in
peripheral circulation which influence testicular functions.
The non significant change in testosterone level and the significant decrease
in estradiol level of CCl4 treated animals in our study was context
with finding of Frezza et al. (1993).
According to Withers et al. (1974) changes in
weight and size of the irradiated testis is related more to depletion and regeneration
of much more numerous cells in various stages of differentiation and are not
a direct indication of stem cell depletion.
Nomura and Yamaoka (1999) proposed that Low-dose gamma-ray
irradiation reduces oxidative damage induced by CCl4 in mouse liver
and suggest that low-dose radiation relieved functional disorder at least in
the liver of mice with active oxygen diseases.
In the present study γ-irradiation treatments represented great atrophy
in testis tissue, pretubular fibrosis and apoptosis in the Leydig cells, context
with the finding of Kangasniemi et al. (1996)
and Meistrich et al. (1996) who proposed after
exposure to low doses of gamma rays differentiating spermatogonia are killed.
The depletion in spermatogonia resulted in a reduction in subsequent spermatozoa.
Also, Konoplia et al. (1996) examined the microscopy
morphological characteristics of Sertoli cells. Leydig's cells and other populations
of testicular cells after prolonged of low dose whole-body gamma-irradiation
and suggests that the existence of gamma-sensor in brain of mammals that involved
on hypothalamic-pituitary-testicular levels in realisation of radiation stress
suppression of Sertoli cell functions at a relatively "low" (0.1-0.5 Gy) doses
by means of hypothalamic releasing factors.
Isao et al. (2004) proposed that mice with BMC
transplants with continuous CCl4 injection had reduced liver fibrosis
and a significantly improved survival rate after BMC transplantation compared
with mice treated with CCl4 alone. This finding introduces a new
concept for the therapy of liver fibrosis.
In the present study BM transplantation empire testicular hormones, many apoptotic
and necrotic observations in the spermatogonia, sertoli cells and primary spermatocytes
and discontinuous seminiferous epithelium context with the finding of Yong-Hoon
et al. (2009). Also, the same observations were recorded when CCl4
or CCl4 irradiated group treated by bone marrow transplantation.
Autoimmune-like complication after BMT leads morphological and functional changes
of target tissues (Levy et al., 2000) and also
associated with gonadotoxicity (Wagner et al., 2005).
In conclusion exposure to consecutive low dose of γ-radiation and bone marrow transplantation impair testicular tissue in a rat treated CCl4 model.
Al-Jahdali, M.O. and A.S.B. Bisher, 2007. Testicular histopathological alterations in rats treated with Sumithion&ref; NP 25/2.5 EC, insecticide. J. Boil. Sci., 7: 520-525.
CrossRef | Direct Link |
Bank, H.L., 1988. Rapid assessment of islet viability with acridine orange and propidium iodide. In Vitro Cellular Dev. Biol. Plant, 4: 266-273.
Bannister, P., T. Handley, C. Chapman and M.S. Losowsky, 1986. A: Hypogonadism in chronic liver disease: Impaired release of luteinising hormone. Br. Med. J., 293: 1191-1193.
Direct Link |
Bergmeyer, H.U., M. Horder and R. Rej, 1986. Approved recommendation (1985) on IFCC methods for the measurement of catalytic concentrations of enzymes. Part 3 IFCC method for alanine aminotransferase. J. Clin. Chem. Clin. Biochem., 24: 481-495.
Direct Link |
Castilla-Cortazar I., M. Garcia, J. Quiroga, N. Diez and F. Diez-Caballero et al., 2000. Insulin-like growth factor-I reverts testicular atrophy in ratsa with advanced cirrhosis. Hepatol., 31: 592-600.
Champlin, R. and R.P. Gale, 1987. Bone marrow transplantation: Its biology and role as treatment for acute and chronic leukemias. Ann. New York Acad. Sci., 511: 447-458.
Feinendegen, L.E., 2005. Evidence for beneﬁcial low level radiation effects and radiation hormesis. Br. J. Radiol., 78: 3-7.
Frezza, E.F., G.E. Gerunda, F. Farinati, M. Plebani and Giacomin et al., 1993. Sex hormones and trace elements in rat CCl4-induced cirrhosis and hepatocellular carcinoma. Eur. J. Cancer Prev., 2: 357-359.
Gong, S.L., S.C. Liu, J.X. Liu, Y.C. Zhang and S.Z. Liu, 2000. Adaptive response of thymocyte apoptosis and cell cycle progression induced by low dose X-ray irradiation in mice. Biomed. Environ. Sci., 13: 180-188.
Joksic, G. and S. Petrovic, 2004. Lack of adaptive response of human lymphocytes exposed in vivo to low doses of ionizing radiation. J. Environ. Pathol. Toxicol. Oncol., 23: 195-206.
Kangasniemi, M., I. Huhtaniemi and M.L. Meistrich, 1996. Failure of spermatogenesis to recover despite the presence of a spermatogonia in the irradiated LBNF1 rat. Biol. Reprod., 54: 1200-1208.
Direct Link |
Keller, A., 1984. Total Serum Protein. In: Clinical Chemistry, Theory, Analysis and Correlation, Kaplan, L.A. and A.J. Pesce (Eds.). St. Lious: Mosby Company, USA, pp: 1400-1402.
Khan, A.A. and M.A. Alzohairy, 2011. Hepatoprotective effects of camel milk against CCl4-induced hepatotoxicity in rats. Asian J. Biochem., 6: 171-180.
CrossRef | Direct Link |
Khan, M.R. and D. Ahmed, 2009. Protective effects of Digera muricata (L.) Mart. on testis against oxidative stress of carbon tetrachloride in rat. Food Chem. Toxicol., 47: 1393-1399.
Klauke, R., E. Schmidt and K. Lorentz, 1993. Recommendations for carrying out standard ECCLS procedures (1988) for the catalytic concentrations of creatine kinase, aspartate aminotransferase, alanine aminotransferase and gamma-glutamyltransferase at 37 degrees C. Standardization committee of the German society for clinical chemistry, enzyme working group of the German society for clinical chemistry. Eur. J. Clin. Chem. Clin. Biochem., 31: 901-909.
PubMed | Direct Link |
Konoplia, E.F., A.V. Chanturiia and E.G. Popov, 1996. Effects of prolonged low-dose gamma irradiation on testes of rats. Radiats. Biol. Radioecol., 36: 291-298.
Lee, S.J., S.A. Choi, C.K. Cho, T.H. Kim, K.S. Jeong, S.Y. Yoo and Y.S. Lee, 2000. Adaptive response is differently induced depending on the sensitivity to radiation-induced cell death in mouse epidermal cells. Cell. Biol. Toxicol., 16: 175-184.
Levy, S., A. Nagler, S. Okon and Y. Marmary, 2000. Parotid salivary gland dysfunction in chronic graft-versus-host disease(cGVHD): A longitudinal study in a mouse model. Bone Marrow Transplant, 25: 1073-1078.
Lin, H.M., H.C. Tseng, C.J. Wang, J.J. Lin, C.W. Lo and F.P. Chou, 2008. Hepatoprotective effects of Solanum nigrum Linn extract against CCl4-iduced oxidative damage in rats. Chem. Biol. Interact., 171: 283-293.
Liu, G., P. Gong, H. Zhao, Z. Wang, S. Gong and L. Cai, 2006. Effect of low-level radiation on the death of male germ cells. Radiat Res., 165: 379-389.
Direct Link |
Lox, C.D., 1984. The effects of acute carbaryl exposure on clotting factor activity in the rat. Ecotoxicol. Environ. Saf., 8: 280-283.
Meistrich, M.L., G. Wilson, W. Ye, C. Thrash and I. Huhtaniemi, 1996. Relation among hormonal treatment, suppression of spermatogenisses and testicular protection from chemothraby induced damaged. Endocrinol., 137: 3823-3831.
Nabeshima, Y., S. Tazuma, K. Kanno, H. Hyogo, M. Iwai, M. Horiuchi and K. Chayama, 2006. Antifibrogenic function of angiotensin II type 2 receptor in CCl4induced liver fibrosis. Biochem. Biophys. Res. Commun., 346: 658-664.
Nomura, T. and K. Yamaoka, 1999. Low-dose y-RAY irradiation reduces oxidative damage induced by CCl4 in mouse liver. Free Rad. Biol. Med., 27: 1324-1333.
Noori, S., N. Rehman, M. Qureshi and T. Mahboob, 2009. Reduction of carbon tetrachloride-induced rat liver injury by coffee and green tea. Pak. J. Nutr., 8: 452-458.
CrossRef | Direct Link |
O`Reilly, R.J., 1983. Allogeneic bone marrow transplantation: Current status and future directions. Blood, 1: 629-941.
O`leary, M., N.K.C. Ramsay, M.E. Jr. Nesbit, D. Hurd and W.G. Woods et al., 1983. Bone marrow transplantation for non-Hodgkin`s lymphoma in children and young adults: A pilot study. Am. J. Med., 74: 497-501.
Direct Link |
Onori, P., S. Morini, A. Franchitto, R. Sferra, D. Alvaro and E. Gaudio, 2000. Hepatic microvascular features in experimental cirrhosis: A structural and morphometrical study in CCl4-treated rats. J. Hepatol., 33: 555-563.
Direct Link |
Pajarinen, J.T. and P.J. Karhunden, 1994. Spermatogenic arrest and sertoli cell-only syndrome-common alcohol-induced disorders of the human testis. Int. J. Androl., 17: 292-299.
Powles, R.L., G. Morgenstern, H.M. Clink, D. Hedley and G. Bandini et al., 1980. The place of bone-marrow transplantation in acute myelogenous leukaemia. Lancet., 315: 1047-1050.
Ranl, A., A. Sahal, A.K. Srivastava and A. Ranl, 2007. Carbanyl induced histopathological changes in the testis of albino rats. J. Anat. Soc. India, 56: 4-6.
Sakaida, I., S. Terai, N. Yamamoto, K. Aoyama, T. Ishikawa, H. Nishina and K. Okita, 2004. Transplantation of bone marrow cells reduces CCl4-induced liver fibrosis in mice. Hepatology, 40: 1304-1311.
CrossRef | Direct Link |
Santamaria, L., R. Martin, J. Codesal and R. Paniagua, 1995. Myoid cell proliferation in rat seminiferous tubules after ischaemic testicular atrophy induced by epinephrine: Morphometric and immunohistochemical (bromo-deoxyuridine and PCNA) studies. Int. J. Androl., 18: 13-22.
Storb, R., E.D. Thomas, P.L. Weiden, C.D. Buckner and R.A. Clift et al., 1976. Aplastic anemia treated by allogeneic bone marrow transplantation: A report on 49 new cases from Seattle. Blood, 48: 817-841.
Direct Link |
Van Steenbergen, W., 1993. Alcohol, liver cirrhosis and disorders in sex hormone metabolism. Acta Clin. Belg., 48: 269-283.
Van Thiel, D.H., J.S. Gavaler, F.L. Slone, C.F. Jr. Cobb, W.I. Jr. Smith, K.M. Bron and R. Lester, 1980. Is feminization in alcoholic men due in part to portal hypertension: A rat model?. Gastroenterol., 78: 81-91.
Wagner, A.M., K. Beier, E. Christen, G.A. Hollander and W. Krenger, 2005. Leydig cell injury as a consequence of an acute graftversus-host reaction. Blood, 105: 2988-2990.
Weber, L.W., M. Boll and A. Stampfl, 2003. Hepatotoxicity and mechanism of action of haloalkanes: Carbon tetrachloride as a toxicological model. Crit. Rev. Toxicol., 33: 105-136.
CrossRef | PubMed | Direct Link |
Withers, H.R., N. Hunter, H.T. Jr. Barkley and B.O. Reid, 1974. Radiation survival and regeneration characteristics of spermatogenic stem cells of mouse testes. Radiat. Res., 57: 88-103.
Direct Link |
Yong-Hoon, K., H. Chang-Su, L. Hyun-Sook, L. Sun-Hwa, M. Kyoung-Sik, C. Moon-Koo and S. Hwa-Young, 2009. Pathological features of bone marrow transplantation-related toxicity in a mouse. J. Vet. Sci., 10: 361-363.
Yoon, Y.S., A. Wecker, L. Heyd, J.S. Park and T. Tkebuchava et al., 2005. Clonally expanded novel multipotent stem cells from human bone marrow regenerate myocardium after myocardial infarction. J. Clin. Invest., 115: 326-338.