Reproductive Organs In Mice Research Articles

NUCB2/nesfatin-1 suppresses the acrosome reaction in sperm within the mouse epididymis

ABSTRACT Nesfatin-1, a polypeptide hormone derived from the nucleobindin 2 (NUCB2) precursor protein, is known to regulate appetite and energy metabolism. Recent studies have also shown that NUCB2/nesfatin-1 is expressed in the reproductive organs of mice. However, the expression and potential role of NUCB2/nesfatin-1 in the mouse epididymis remain unclear. Therefore, we investigated the expression of NUCB2/nesfatin-1 in the mouse epididymis and its potential function. NUCB2/nesfatin-1 was detected in the epididymis by qRT-PCR and western blotting, and high expression levels were observed in epididymal epithelial cells by immunohistochemical staining. Pregnant mare’s serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG) injections significantly increased NUCB2/nesfatin-1 expression in the epididymis. After castration, NUCB2/nesfatin-1 expression in the epididymis decreased, but was significantly increased by testosterone injection. Nesfatin-1-binding sites were found in the middle piece of testicular sperm, but were scarcely detected in the sperm head. By contrast, nesfatin-1 binding sites were identified on the sperm head within the epididymis. Furthermore, nesfatin-1 treatment inhibited the acrosome reaction in epididymal sperm. These results suggest that the nesfatin-1 protein produced in the epididymis binds to nesfatin-1 binding sites on the sperm head and plays a role in suppressing the acrosome reaction before ejaculation.

The Expression of the Cold Shock Protein RNA Binding Motif Protein 3 is Transcriptionally Responsive to Organ Temperature in Mice.

Mild hypothermia, i.e. maintenance of organ temperature by up to 8°C lower than body temperature, is a critical strategy for exerting some functions of the cells and organs normally, and is an useful therapy for recovering properly from some diseases, including myocardial infarction, cardiac arrest, brain injury, and ischemic stroke. Nevertheless, there were no focusses so far on organ temperature and potential responses of gene expression to organ temperature in organs of homeothermic animals that survive under normal conditions. The present study aimed to assess organ temperature in homeothermic animals and evaluate the effect of their organ temperature on the expression of the cold shock protein RNA binding motif protein 3 (RBM3), and to gain insights into the organ temperature-mediated regulation of RBM3 gene transcription via Nuclear factor β-light-chain-enhancer of activated B cells (NF-κB) p65, which had been identified as a transcription factor that is activated by undergoing the Ser276 phosphorylation and promotes the RBM3 gene expression during mild hypothermia. We measured the temperature of several organs, where RBM3 expression was examined, in female and male mice. Next, in male mice, we tested NF-κB p65 expression and its Ser276 phosphorylation in organs that have their lower temperature than body temperature and compared them with those in organs that have their temperature near body temperature. Organ temperature was around 32°C in the brain and reproductive organs, which is lower than the body temperature, and around 37°C in the heart, liver, and kidney, which is comparable to the body temperature. The expression of RBM3 was detected greatly in the brain and reproductive organs with their organ temperature of around 32°C, and poorly in the heart, liver, and kidney with their organ temperature of around 37°C. In accordance with the changes in the RBM3 expression, the NF-κB p65 Ser276 phosphorylation was detected more greatly in the testis and brain with their organ temperature of around 32°C, than in the heart, liver, and kidney with their organ temperature of around 37°C, although the NF-κB p65 expression was unchanged among all the organs tested. Our data suggested that organ temperature lower than body temperature causes the expression of RBM3 in the brain and reproductive organs of mice, and that lower organ temperature causes the NF-κB p65 activation through the Ser276 phosphorylation, resulting in an increase in the RBM3 gene transcription, in the brain and reproductive organs of mice. The study may present the possibility that organ temperature-induced alterations in gene expression are organ specific in homeotherms and the possibility that organ temperature-induced alterations in gene expression are transcriptionally regulated in some organs of homeotherms.

Reproductive toxicity assessment of Olusosun municipal landfill leachate in Mus musculus using abnormal sperm morphology and dominant lethal mutation assays.

Mixture of xenobiotics in Olusosun landfill leachates (OSL) induced somatic and germ cell genotoxicity in eukaryotic cells. However, whether the DNA-damaged germ cells can increase reproductive failure, embryotoxicity and/or teratogenicity during fertilization remained unclear. The study herein investigated reproductive toxicity and embryotoxic effects of OSL in mice using abnormal sperm morphology and dominant lethal mutation assays. Six mice per group were exposed to 0.5 mL of 5, 10, 25, and 50% OSL (v/v, leachate/distilled water) for 5 consecutive days. Similar treatment was giving to distilled water and cyclophosphamide (20 mg/kg body weight), as negative and positive control groups, respectively. At 35 day post-treatment, the mice were sacrificed and examined for cauda epididymal abnormal sperm morphology, testicular weight change and histopathological lesions. Male mice were mated to untreated nulliparous females (1 treated male per 2 untreated females) until vaginal plugs were observed. Pregnant females were sacrificed on 14th day post-mating and uterine content examined for number of implants per female, resorptions, and live and dead fetuses. OSL significantly increased teratozoospermia by 31.02% with amorphous sperm head having the highest frequency and sperm with two heads, the least. Histology of the testes revealed congestion of the interstitial blood vessels, spermatid retention and disorganization of the germinal epithelium from the basal compartment. OSL insignificantly increased absolute and relative testes weights but reduced body weight of exposed mice. There was insignificant induction of dominant lethal mutation, although low fertility was observed in the treated mice. The analyzed physico-chemical parameters and heavy metals/metalloids in OSL were higher than permissible limits. The metals, physico-chemical parameters and other unanalyzed substances in OSL induced abnormal sperm morphology, altered testes pathology, but did not significantly induce dominant lethal mutation in mice. Constituents of OSL are toxic to the male reproductive organs in mice and suggests harmful impact on public health. Indiscriminate disposal of solid wastes in the environment should be prevented.

Effects of Iron Oxide Nanoparticles on Mouse Sperm Parameters and Testicular Tissue

Background: Iron oxide nanoparticles are commonly used for various purposes, such as biomedical, medical, and cosmetic services and research. However, there is a little information about the effects of the nanoparticles on human health. The current investigation was conducted to evaluate the adverse effects of iron oxide nanoparticles (FeNP) on the reproductive organs of mice, such as the testicular tissue and sperm cells. Methods: Twenty-eight male NMRI mice were randomly divided in four groups (N=7). The control group received only a regular diet. The experimental groups were administered FeNP in doses of 50, 150 and 300 mg/Kg intraperitoneally (IP), over four days. Epididymal sperm parameters, such as sperm number and motility were assessed by computer-assisted sperm analysis (CASA). Stereological analysis was also conducted on the histological sections. Results: The results demonstrated that FeNP (300 mg/Kg/day) caused a significant decrease in the sperm parameters, such as motility, spermatogonia, primary spermatocytes, spermatid, Sertoli, Leydig cells, total length of seminiferous tubules, and testicular interstitial tissue volumes. Conclusion: In summary, FeNP affected several reproductive tissue and cellular parameters at the administered dosage. Further research is required to examine the mechanism of action of FeNP the mice reproductive system.

Copper Nanoparticles Show Obvious in vitro and in vivo Reproductive Toxicity via ERK Mediated Signaling Pathway in Female Mice

Copper nanoparticles (Cu-NPs) and other inorganic nanomaterials have caused increasing concern owing to be widely used. Early studies have reported that they can result in injuries to the kidney, liver and spleen of mice; cause embryonic damage; and inhibit the reproductive capacity of red worms. However, few studies have reported the toxicity of Cu-NPs on the reproductive systems of mammals. In the present work, we explored the cytotoxicity of Cu-NPs in human extravillous trophoblast cells and in the reproductive organs of mice. Cu-NPs induced ovarian and placental pathophysiology and dysfunction in mice. These nanoparticles also induced apoptosis and suppressed the proliferation of human extravillous trophoblast cells and caused cell cycle arrest at the G2/M phase in a time-and dose-dependent manner. Cu-NPs can significantly damage the mitochondrial membrane potential (MMP), which suggests that Cu-NPs can activate the mitochondria-mediated apoptosis signaling pathway. We also observed that Cu-NPs significantly inhibit the expression of BRAF, ERK, and MITF expression, all of which are important genes in the ERK signaling pathway. Our research demonstrated that Cu-NPs exert obvious reproductive toxicity in mice by disrupting the balance of sex hormones and exert cytotoxicity on human extravillous trophoblast cells, and ERK signaling and the mitochondrial apoptosis pathway made great contribution to the toxicity of Cu-NPs on female mice.

Effect of dietary estrogens from bovine milk on blood hormone levels and reproductive organs in mice

Cows are often milked until 60 d before their next expected calving. Milk from cows in the third trimester of pregnancy contains up to 20 times more estrogens than milk from nonpregnant cows. The aim of this study was to evaluate whether exposure to known doses of estrogens from bovine milk could affect blood hormone levels in mice and influence their reproductive organs. This study was performed with 30 intact male and 30 ovariectomized female mice. Mice of each sex were randomly divided into 3 experimental groups, each with 6 animals of each sex, and a control group with 12 animals of each sex. The first experimental group received 4mL of milk each day from a pregnant cow with natural estrone (E1) and 17β-estradiol (E2) in concentrations 0.093 and 0.065ng/mL, respectively. The second experimental group received 4mL of the same milk each day, with an added 10ng/mL of both E1 and E2. The third experimental group received 4mL of the same milk each day, with an added 100ng/mL of both E1 and E2. The control group received no milk. After 8 d of treatment, mice were euthanized, blood was collected, and the uteruses, testes, and seminal vesicles were weighed. The results of our study demonstrated that consumption of native milk from a pregnant cow did not affect plasma E1 and E2 levels in either sex; uterine weight in females; or testosterone levels and testes and seminal vesicle weights in males. Similarly, we found no changes in the group that received the milk with an added 10ng/mL of E1 and E2. We did observe elevated plasma estrogens in both sexes, increased uterus weight in females, and decreased plasma testosterone levels in males from the group that received milk with an added 100ng/mL of E1 and E2. However, concentrations in the third group exceeded the physiological concentration of milk estrogens by 1,000 times, so it would be extremely unlikely to find such concentrations in native cow milk.

Effect of Sialoadenectomy on the development of male reproductive organs in mice (Mus musculus).

Submandibular gland is rich source of epidermal growth factor (EGF). To investigate the role of salivary EGF on the development of male reproductive system we have performed the sialoadenectomy (removal of submandibular glands) of the 20 days old male mice and this sialoadenectomised mice was sacrificed on 45, 60 and 90th day. The testis, seminal vesicle, prostate gland, caput and cauda epididymis were dissected out for protein estimation and histological studies. It was found that the there was significant loss in the weight of these organs, protein content in the sialoadenectomised mice as compared to control. The histological structures of these organs were also changed in the sialoadenectomised mice. Keyword: Sialoadenectomy, Histology, weight, Protein

Postnatal exposure to low-dose decabromodiphenyl ether adversely affects mouse testes by increasing thyrosine phosphorylation level of cortactin

Decabromodiphenyl ether (decaBDE) is a brominated flame retardant used in many commercial products such as televisions, computers, and textiles. Recent reports indicate that decaBDE adversely affects male reproductive organs in mice, but the underlying molecular mechanisms remain unknown. We hypothesized that decaBDE affects mouse testes by altering the expression and phosphorylation level of cortactin (CTTN), an F-actin-binding protein that is similar to flutamide, and we performed western blot analyses on testicular samples from mice subcutaneously injected with decaBDE (0.025, 0.25, and 2.5 mg/kg body weight/day) on postnatal days 1 to 5. Mice treated with low-dose decaBDE (0.025 mg/kg) showed reduced testicular weight, sperm count, elongated spermatid and Sertoli cell numbers, as well as induced Tyr phosphorylation of CTTN and reduced the expression level of p60 Src tyrosine kinase (SRC). Further, 0.25 and 2.5 mg/kg decaBDE-exposed groups produced an decrease the expression level of CTTN. High-dose decaBDE (2.5 mg/kg) showed increased abnormal germ cells, as well as induced Ser phosphorylation of CTTN and activated extracellular signal-regulated kinase (ERK1/2); however, high-dose decaBDE did not affect testicular weight and sperm count. These findings suggest that postnatal exposure to low-dose decaBDE inhibits mouse testicular development by increasing Tyr phosphorylation of CTTN, although different mechanisms may be involved depending on the dose of decaBDE.

Severe abnormalities in the reproductive organs of mice caused by chemical substances contained in heavy oil

It is well known that heavy oil pollution results in various negative impacts on the marine environment. Although there is a low possibility of direct exposure to heavy oil, the chemical substances contained in heavy oil may be released into the environment and accumulated by marine organisms which in turn can be taken by humans via the food chain. In this study, we examined the biological risk of heavy oil extract using the common mouse, whose genetic backgrounds and immune system are well known and relatively homologous to humans. Water-soluble fraction (WSF) was extracted from heavy oil with water and the extract orally administrated to female or male mice for 7 days. In the WSF administrated group, cystoma-like formation was observed in the ovary in approximately 80% of female mice. On the other hand, we found that the prostate gland size in male mice was markedly reduced in comparison with male control mice. Continuous administration of WSF for 28 days resulted in continued hypertrophy of the cystoma around the ovary and atrophy in the prostate gland. In addition, it was revealed that chemical substances within WSF have estrogenic activity. A major component of heavy oil, polycyclic aromatic hydrocarbons (PAHs), is known to present estrogenic activity. It is likely that the cystoma-like formation in female mice and atrophy of prostate gland in male resulted of estrogenic substances present in the WSF which might be the PAHs.

GPR30 Does Not Mediate Estrogenic Responses in Reproductive Organs in Mice

The G protein-coupled receptor Gpr30 (Gper) was recently claimed to bind to estradiol and to activate cytoplasmic signal transduction pathways in response to estradiol. However, there are conflicting data regarding the role of Gpr30 as an estrogen receptor (ER): several laboratories were unable to demonstrate estradiol binding to GPR30 or estradiol-activated signal transduction in Gpr30-expressing cells. To clarify the potential role of Gpr30 as an ER, we generated Gpr30-deficient mice. Although Gpr30 was expressed in all reproductive organs, histopathological analysis did not reveal any abnormalities in these organs in Gpr30-deficient mice. Mutant male and female mice were as fertile as their wild-type littermates, indicating normal function of the hypothalamic-pituitary-gonadal axis. Moreover, we analyzed estrogenic responses in two major estradiol target organs, the uterus and the mammary gland. For that purpose, we examined different readout paradigms such as morphological measures, cellular proliferation, and target gene expression. Our data demonstrate that in vivo Gpr30 is dispensable for the mediation of estradiol effects in reproductive organs. These results are in clear contrast to the phenotype of mice lacking the classic ER alpha (Esr1) or aromatase (Cyp19a1). We conclude that the perception of Gpr30 (based on homology related to peptide receptors) as an ER might be premature and has to be reconsidered.

Dandelion T-1 extract up-regulates reproductive hormone receptor expression in mice

Reproductive hormones exert their actions via receptors in diverse tissues. In this study, we examined the expression of estrogen receptors (ERalpha and ERbeta), progesterone receptor (PR), and follicle-stimulating hormone receptor (FSHR) in the adipose tissue and reproductive organs of mice following oral treatment with Dandelion T-1 extract (DT-1E) for 6 weeks. Quantitative assays by real-time reverse transcription polymerase chain reaction showed enhanced expression of ERalpha and ERbeta mRNA in the adipose tissue of mice fed a diet containing DT-1E compared with the control group fed a plain diet. Furthermore, following gonadotropin injection, higher mRNA expression of ERalpha, ERbeta and PR in the uterus and FSHR in the ovary was found in the DT-1E group compared with the control group. An immunohistochemical study also showed increased levels of the above-mentioned receptors in the DT-1E group. The present study shows that oral intake of DT-1E up-regulates ERalpha, ERbeta, PR and FSHR expression in mice, suggesting the potential application of DT-1E for the clinical treatment of reproductive hormone-related disturbances.

Synaptopodin Protects Against Proteinuria by Disrupting Cdc42:IRSp53:Mena Signaling Complexes in Kidney Podocytes

The actin-based foot processes of kidney podocytes and the interposed slit diaphragm form the final barrier to proteinuria. Mutations affecting several podocyte proteins cause disruption of the filtration barrier and rearrangement of the highly dynamic podocyte actin cytoskeleton. Proteins regulating the plasticity of the podocyte actin cytoskeleton are therefore of critical importance for sustained kidney barrier function. Synaptopodin is an actin-associated protein essential for the integrity of the podocyte actin cytoskeleton because synaptopodin-deficient mice display impaired recovery from protamine sulfate-induced foot process effacement and lipopolysaccharide-induced nephrotic syndrome. Moreover, bigenic heterozygosity for synaptopodin and CD2AP is sufficient to induce spontaneous proteinuria and focal segmental glomerulosclerosis-like glomerular damage in mice. Mechanistically, synaptopodin induces stress fibers by blocking the proteasomal degradation of RhoA. Here we show that synaptopodin directly binds to IRSp53 and suppresses Cdc42:IRSp53:Mena-initiated filopodia formation by blocking the binding of Cdc42 and Mena to IRSp53. The Mena inhibitor FP(4)-Mito suppresses aberrant filopodia formation in synaptopodin knockdown podocytes, and when delivered into mice protects against lipopolysaccharide-induced proteinuria. The identification of synaptopodin as an inhibitor of Cdc42:IRSp53:Mena signaling defines a novel antiproteinuric signaling pathway and offers new targets for the development of antiproteinuric therapeutic modalities.

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.

Immunohistochemical Localization of Klotho Protein in Brain, Kidney, and Reproductive Organs of Mice

Klotho mutant mouse (kl-/-), a mouse model for human aging, exhibits various phenotypes in a wide range of organs including arteriosclerosis, neural degeneration, skin and gonadal atrophy, pulmonary emphysema, calcification of soft tissues, and cognition impairment. Klotho mRNA, however, is expressed only in brain, kidney, reproductive organs, pituitary gland, and parathyroid gland. Therefore it remains to be elucidated how lack of Klotho protein in these limited organs leads to the variety of phenotypes. To shed light on mechanisms by which Klotho protein acts on distant targets, we examined localization of Klotho protein in brain, kidney, and reproductive organs, and analyzed brain and kidney in kl-/- mice searching for changes in target regions in these organs. In brain, Klotho proteins were localized at choroid plexus, where the proteins were dominantly localized at the apical plasma membrane of ependymal cells. In kl-/- brain, reduction of synapses was evident in hippocampus, suggesting a role of Klotho as a humoral factor in cerebrospinal fluid. Klotho proteins in kidney localized at distal renal tubules. Interestingly, in kl-/-mice, type IIa Na/phosphate (Pi) cotransporters, which function at the proximal renal tubules in reabsorption of phosphate ions, were translocated. This suggests that Klotho protein in kidney is implicated in calcium homeostasis which regulates localization of type IIa Na/Pi cotransporters via parathyroid hormone (PTH). Klotho proteins in reproductive organs were expressed only in mature germ cells, although in kl-/- mice germ cell maturation was arrested at earlier stages. Thus, Klotho proteins not only function as a humoral factor, but also are implicated in hormonal regulation, which may explain why mutation of klotho gene results in a variety of phenotypes.

Multiple mechanisms are involved in apoptotic cell death in the mouse uterus and vagina after ovariectomy

Withdrawal of sex hormones by gonadectomy results in rapid involution of mouse reproductive organs. To study the regression mechanism in the uterus and vagina after ovariectomy, histologic and biochemical changes were examined. Apoptotic cells were detected by in situ 3′-DNA nick end labeling method and electron microscopy, while the number of cells showing incorporation of bromo-deoxyuridine (BrdU) decreased in the uterus and vagina after ovariectomy. DNA fragmentation in the uterus was observed even at estrus and the degree of fragmentation increased after ovariectomy. DNA fragmentation in the vagina occurred 1–5 days after ovariectomy. Semi-quantitative RT-PCR revealed that expression of Fas-ligand and tumor necrosis factor-α (TNF-α) mRNA in the uterus and vagina was increased by ovariectomy. These results suggest that apoptotic cell death is induced by ovariectomy through the mediation of both Fas and TNF-α in the mouse uterus and vagina; however, uterine and vaginal cells in CBA lpr cg / lpr cg mice lacking functional Fas showed apoptosis, indicating that Fas is not the sole regulator of apoptosis in female reproductive organs in mice.

Progressive impairment of kidneys and reproductive organs in mice lacking Rho GDIalpha.

The Rho small G protein family members regulate various actin cytoskeleton-dependent cell functions. The Rho GDI (GDP dissociation inhibitor) family, consisting of Rho GDIalpha, -beta, and -gamma, is a regulator that keeps the Rho family members in the cytosol as the GDP-bound inactive form and translocates the GDP-bound form from the membranes to the cytosol after the GTP-bound form accomplishes their functions. Rho GDIalpha is ubiquitously expressed in mouse tissues and shows GDI activity on all the Rho family members in vitro. We have generated mice lacking Rho GDIalpha by homologous recombination to clarify its in vivo function. Rho GDIalpha -/- mice showed several abnormal phenotypes. Firstly, Rho GDIalpha -/- mice were initially viable but developed massive proteinuria mimicking nephrotic syndrome, leading to death due to renal failure within a year. Histologically, degeneration of tubular epithelial cells and dilatation of distal and collecting tubules were readily detected in the kidneys. Secondly, Rho GDIalpha -/- male mice were infertile and showed impaired spermatogenesis with vacuolar degeneration of seminiferous tubules in their testes. Thirdly, Rho GDIalpha -/- embryos derived from Rho GDIalpha -/- female mice were defective in the postimplantation development. In addition, these morphological and functional abnormalities showed age-dependent progression. These results suggest that the signaling pathways of the Rho family members regulated by Rho GDIalpha play important roles in maintaining the structure and physiological function of at least kidneys and reproductive systems in adult mice.

Morphological demonstration of the immune privilege in the testis using adjuvants: tissue responses of male reproductive organs in mice injected with Bordetella pertussigens.

The testis, the epididymis and the prostate are immunologically suppressed organs in which allogeneic tissue grafts can survive for a long time. In the present study, morphological features of these three organs after systemic administration of immunopotentiators was investigated in mice to determine whether or not this treatment can affect their immunosuppressive circumstances. The animals were intravenously injected with adjuvants, Bordetella pertussigens, then killed 7-10 days later for histological examination. The results showed that the testicular interstitium was completely free from leukocyte infiltration but that the accessory glands (the prostate, the coagulating gland and the seminal vesicle), the vas deferens, the epididymis and the ductuli efferentes received extravasation of leukocytes into their interstitial tissues. This indicates that the testis is resistant to leukocyte infiltration compared with the epididymis and the prostate.

Effects of gossypol acetic acid, a male antifertility drug, on the epididymis of DBA/2J mice

Recent studies have demonstrated that gossypol acetic acid, a phenolic compound isolated from cotton plants, is a promising reversible male contraceptive in rats and in human beings. Since very little information on the light and ultrastructural effects of the compound on the male reproductive organs in mice is available, this study was undertaken to investigate the effects of the agent on epididymal tissue and spermatozoa in DBA/2J mice.Gossypol acetic acid was purchased from Sigma Chemical Co., MO. The agent, mixed in olive oil, was administered orally to four groups of mice. Each group received either 0 (control) , 10,20 or 40 mg/kg of the agent twice per week for periods up to 96 days. Animals were sacrificed in pairs at 3,6,9 and 12 weeks. Motility, viability and sperm numbers were determined. Epididymis was fixed in 2% glutaraldehyde, post fixed in 1% osmium tetroxide, dehydrated in an acetone series and embedded in Epon 812. Ultrathin sections were stained and examined under the Philips 200 electron microscope.

Abnormalities in the reproductive system of aged mice after neonatal estradiol exposure.

Female mice of the BALB/c strain were treated neonatally with 17 beta-estradiol (E2) or sesame oil and sacrificed at 20 months of age. Neonatal treatment of mice with E2 resulted in the development of vaginal lesions, including adenosis, adenocarcinoma and squamous-cell carcinoma. While the neonatal treatment also induced squamous metaplasia in the uterine epithelium, development of uterine adenomatous hyperplasia was markedly inhibited in the estrogen-treated mice when compared to the oil-treated controls. However, neonatal exposure to E2 resulted in a high incidence of ovarian tumors and epithelial hyperplasia of the oviduct. Thus, the effects of neonatal treatment with estrogen appeared to interact with the usual effects of aging, modifying the development of pathological abnormalities in the various reproductive organs of mice.

Lack of Toxicity of Enflurane on Male Reproductive Organs in Mice

Enflurane has been shown to increase slightly the percentage of abnormal spermatozoa in mice. To examine in more detail possible adverse effects of enflurane on male reproductive organs, 125 Swiss/ICR mice were exposed to 0.3% enflurane for up to 18 months; a control group of 125 mice was exposed concurrently to air. Exposures were for 4 hours/day, 5 days/week. After 12 months of exposure, groups of 25 enflurane-treated and control mice were killed, and chromosomal analysis of spermatogonial cells was performed. After 18 months exposure, remaining mice were killed and epididymal sperm were collected for morphologic examination. In addition, the reproductive organs of all mice dying or killed throughout the study were examined histologically. Approximately 1% of spermatogonial cells from both enflurane-treated and control mice had aberrant chromosomes. The average percentage of morphologically abnormal sperm was 9.4 +/- 1.7 for enflurane-treated mice and 6.5 +/- 1.3 for control mice; the difference was not statistically significant (p = 0.18). Finally, there was no difference between the treated and control mice in histologic appearance of reproductive organs. It was concluded that long-term exposure to enflurane has no adverse effects on male reproductive organs in mice.