Effects of neonatal exposure to diethylstilbestrol on protein expression by vagina and uterus in mice.

Neonatal treatment of female mice with diethylstilbestrol (DES) results in genital tract abnormalities including ovary-independent vaginal proliferation and cornification. Protein profiles were examined in vagina and uterus from 45-day-old, ovariectomized C57BL/Tw mice which had been given 5 daily injections of 2 micrograms DES or oil vehicle alone from the day of birth, and in those from 45-day-old, ovariectomized mice given 3 daily injections of 0.1 microgram DES from 42 days of age. Proteins extracted were analyzed by two-dimensional polyacrylamide gel electrophoresis. In the vagina, expression of 37 non-keratin proteins was altered by postpubertal injections of DES as compared with the controls. In the neonatally DES-exposed vagina, expression of 26 of 37 proteins was altered as compared with controls. In the uterus, expression of 22 proteins was altered in the postpubertally DES-exposed group as compared with that in the control; however, the protein expression pattern of the neonatally DES-exposed group closely resembled that of the control except for one protein (no. 23, pI = 6.1, MW = 39.5 kDa) which was specifically increased in the neonatally DES-exposed group. By immunoblot analysis, 6 keratin polypeptides (49.5, 50, 52, 53, 57 and 58 kDa) were identified in vaginae of ovariectomized mice exposed neonatally and postpubertally to DES and of the controls. These results indicate that neonatal DES exposure induces organ specific alterations in the synthesis of proteins in mouse vagina and uterus.     

Alterations in hypothalamic and pituitary hormone levels induced by neonatal treatment of female mice with diethylstilbestrol.

Neonatal female mice of the NMRI strain were treated with the synthetic estrogen diethylstilbestrol (DES), 5 micrograms daily for the first 5 days after birth, or with vehicle only. Levels of LH and FSH (pituitary and serum) and LHRH (hypothalamus) were measured by radioimmunoassay (RIA) in 6- to 56-day-old females with 6- to 7-day intervals. Compared to controls, DES-treated females had low levels of LH on days 6, 12, and 21 in the pituitary, and on days 6 and 12 in serum; increased LH levels were seen in both the pituitary and serum on day 42. The FSH levels of DES-treated females were decreased on days 6 and 12 in the pituitary and on day 6 in serum; an increased FSH content occurred on day 21 in the pituitary. In the preoptic area and basal hypothalamus of DES-treated females, levels of LHRH were increased on day 21 and decreased on day 42. On day 56, the serum levels of FSH and LH and the hypothalamic content of LHRH were similar in controls and DES females. A second study including both synthetic and natural estrogen was performed in 12-day-old females. Treatment with 10(-2) micrograms DES or lower doses or 5 micrograms estradiol-17 beta (E2) on days 1 to 5 after birth had no depressive effect on serum LH. The hypothalamic-pituitary-ovarian feedback system reacted similarly to ovariectomy and E2 challenge in 15-day-old control and DES-treated females. DES-treated 56-day-old females had a reduced LH response to ovariectomy but increased response to exogenous E2 compared to controls. These results show that neonatal treatment with DES has pronounced effects on the hypothalamic-pituitary system in the developing female mouse, which may be of importance for the altered ovarian function in these females as adults.     

Ovarian dysfunction,obesity and pituitary tumors in female mice following neonatal exposure to low-dose diethylstilbestrol

In a previous study, we found that early life exposure to low-dose diethylstilbestrol (DES) induced early onset of spontaneous abnormalities in estrus cycle and shortened survival in female Sprague-Dawley rats. In order to confirm the repeatability of the previous study, neonates of C57BL/6J mice were orally administered DES at doses of 0.005, 0.05, 0.5 and 5 μg/kg/day, and the aging of their reproductive function was observed. As a result, delayed toxicity on ovarian function was found in females treated with 0.5 μg/kg/day of DES. Concomitantly, the females in the 0.05 μg/kg/day of DES, or greater, groups, had increased body weights and, in the 0.5 μg/kg/day of DES, or greater, groups, had developed pituitary tumors, which were causal factors in their accelerated mortality. Thus, we found that early life exposure to low-dose DES induced early onset of spontaneous abnormalities in estrus cycle not only in female rats but also in female mice.     

Nonneoplastic changes induced in female C3H mice by chronic exposure to diethylstilbestrol or 17 beta-estradiol

The long-term nonneoplastic effects of estrogenic diets were studied in female C3H/HeJ and C3HeB/FeJ mice. C3H/HeJ mice received diets containing 0, 10, 100, or 500 ppb diethylstilbestrol (DES) or 100, 1000, or 5000 ppb 17 beta-estradiol (E2) from 6 to 110 wk of age. C3HeB/FeJ females were fed diets containing nominal concentrations of 0, 10, 100, or 500 ppb DES from 6 to 136 wk of age. Responses of both strains to DES were qualitatively identical. Histological changes in the reproductive tract induced or increased by DES in both strains and by E2 in C3H/HeJ mice included stromal mucoid changes in the vagina and cervix, epithelial keratinization in the vagina, and glandular hyperplasia in the uterine horns. Increasing doses above 10 ppb DES or 100 ppb E2 increased the prevalence and, in some cases, severity of these responses. Dose-responses to DES for these endpoints were virtually indistinguishable in the two strains. At 10 ppb DES or 100 ppb E2 there were minimal or no observable effects. When the nonneoplastic dose-response data were compared with neoplastic dose-response data previously reported, no consistent relation between doses causing neoplastic and nonneoplastic responses was seen for the two estrogens.     

Cell proliferation induced in the kidneys and livers of rats and mice by short term exposure to the carcinogen p-dichlorobenzene

Cell proliferation in the kidneys and livers of rats and mice exposed short-term to p-dichlorobenzene (p-DCB) was evaluated by immunohistochemical measurement of bromodeoxyuridine (BrdU) incorporation into nuclei of DNA-synthesizing cells. p-DCB was given by gavage at two doses up to 600 mg/kg body weight for 4 days. The cumulative fraction of proliferating cells was increased in the proximal tubule epithelial cells of male rats at the high dose, but not at the low dose nor in females at either dose using gamma-glutamyl transferase reaction to identify tubular cells. Also, no increase in cell proliferation was found in mouse kidneys. The fractions of proliferating cells in the livers of rats and mice of both sexes were also increased. The increased cell proliferation in only male rat kidney and in the livers of mice of both sexes correlates with the reported carcinogenic effects of p-DCB in those tissues. However, the finding that p-DCB also induced cell proliferation in the livers of rats of both sexes, which were not a site of p-DCB-induced tumors in bioassays, and in female mice at the low dose, which was not affected by an increase in tumors, reveals a lack of concordance and indicates that acute induction of cell proliferation is not sufficient to lead to carcinogenesis.     

Chronic low dose corticosterone exposure decreased hippocampal cell proliferation, volume and induced anxiety and depression like behaviours in mice

A dysregulated hypothalamic-pituitary-adrenal axis (HPA) has been implicated in major depressive disorder and most commonly used animal models of depression have been shown to elevate circulating levels of plasma corticosterone. We have compared the effects of chronic and acute corticosterone administration on hippocampal cell proliferation (as measured by BrdU immunohistochemistry), hippocampal volume and the appearance of anxiety (light dark box) and depression (forced swim test) like behaviours in CD1 mice. We have also examined the effects of chronic administration of fluoxetine and imipramine on these parameters. Chronic (14 days) but not acute treatment with corticosterone resulted in reduced hippocampal cell proliferation and granule cell layer volume, these changes were prevented by co-administration of imipramine and fluoxetine. In contrast, acute and 7 day but not 14 or 21 day treatment with corticosterone gave rise to a "depressed" phenotype in the forced swim test. Mice treated for 14 days with corticosterone also developed an anxious phenotype in the light dark box but only upon repeated testing. The results presented here demonstrate that moderately elevated corticosterone for a prolonged period is sufficient to induce cellular changes in the hippocampus that are prevented by chronic administration of antidepressants.     

A mechanistic study of proliferation induced by Angelica sinensis in a normal gastric epithelial cell line

It has been reported that an extract from Angelica sinensis mainly consisting of polysaccharides (95%) prevented ethanol- or indomethacin-induced gastric mucosal damage (Cho CH et al. Planta Med 2000;66:348-51). However, it is not known whether Angelica sinensis has a direct stimulatory effect on the healing of gastric mucosal lesions. To study the hypothesis that Angelica sinensis has a direct mucosal healing effect in rats and in isolated gastric epithelial cells, we assessed the wound repair in both animals and normal cell culture (RGM-1), as well as [3H]thymidine incorporation, ornithine decarboxylase (ODC) activity, and ODC protein and c-Myc protein expression after different treatments in RGM-1 cells. We found that Angelica sinensis crude extract (ASCE) dose-dependently enhanced gastric ulcer healing in rats and promoted wound repair in RGM-1 cells. It also significantly stimulated [3H]thymidine incorporation and ODC activity in RGM-1 cells in a concentration-dependent manner. ODC and c-Myc protein expression was also increased as a result of this process. DL-alpha-difluoromethyl-ornithine repressed the [3H]thymidine incorporation and ODC activity induced by ASCE. Pretreatment with c-Myc antisense oligodeoxynucleotides blocked the stimulatory action of ASCE on [3H]thymidine incorporation and ODC protein expression. These data suggest that ASCE has a direct mucosal healing effect on gastric epithelial cells, while ODC and c-Myc are closely associated with this effect.     

The relationship between liver peroxisome proliferation and adipose tissue atrophy induced by peroxisome proliferator exposure and withdrawal in mice

We have previously demonstrated that severe adipose tissue atrophy occurs upon dietary treatment of mice with potent peroxisome proliferators (PPs). This atrophy occurs subsequent to peroxisome proliferation in the liver and may represent a novel addition to the pleiotropic effects exerted by PPs. In the present study we have characterized the recovery of mice from such atrophy following cessation of exposure. Following termination of treatment with perfluorooctanoic acid (PFOA) for 7 days, the adipose tissue atrophy was rapidly reversed, beginning on 2-5 days of recovery and being complete within 10 days. In contrast, hepatic peroxisome proliferation recovered much more slowly, indicating that these processes are not strictly coordinated. Analysis of lipoprotein lipase and hormone-sensitive lipase activities in adipose tissue revealed that the decrease and increase in these activities, respectively, caused by PFOA were both reversed within 10 days of recovery. Overall, these data provide further support for our previous conclusion that the adipose tissue atrophy induced by PFOA is caused, at least in part, by changes in the activities of lipoprotein lipase and hormone-sensitive lipase. The serum level of cholesterol, which increased after termination of PFOA treatment, returned to normal with a time-course similar to the recovery of adipose tissue weight, although hepatic peroxisome proliferation was still present. The possible relationship between the reduction in serum cholesterol and/or in its availability to peripheral tissues and the associated atrophy of adipose tissues caused by PPs is discussed.     

五种天然药物抑制晶状体上皮细胞增殖效应比较

目的：对五种天然药物姜黄素（curcumine,Cur）、榄香烯（elemene,Ele）、三氧化二砷（arsenite trioxide,As2O3）、雷公藤内酯醇（triptolide,Tfi）、莪术（rhizoma curcumae,Rc）抑制重组人碱性成纤维细胞生长因子（recombinant human basic fibroblast growth factor,rhbFGF）诱导的牛晶状体上皮细胞（lens epithelial cell,LEC）增殖效应进行比较。方法：将rhbFGF诱导体外培养的LEC发生增殖,并用Cur、Ele、As2O3、Tri、Rc分别与其共同孵育后,用MTT法检测LEC的活性：用流式细胞术（flow cytometer,FCM）检测LEC增殖细胞核抗原（proliferating cell nuclear antigen,PCNA）表达。结果：增殖组LEC活性、PCNA蛋白表达显著高于对照组（P〈0．01）;Cur组、Ele组、As2O3组、％组、Rc组的LEC活性、PCNA蛋白表达均比增殖组显著降低（P〈0．01）。其中Cur、Ele的作用最强,As2O3的作用次之,Tri作用较弱,Rc作用最弱（P〈0．01）。Cur和Ele的作用相近（P〉0．05）。结论：五种天然药物Cur、Ele、As2O3、Tri、Rc均可抑制LEC增殖。Cur和Ele的作用最佳,有希望成为防治后发性白内障的有效药物。     

肾上腺髓质素在肾间质纤维化实验小鼠肾脏细胞增殖中的作用

目的探讨肾上腺髓质素(ADM)在梗阻性肾病中对细胞增殖的影响。方法采用单侧输尿管结扎(UUO)的方法制备梗阻性肾病模型,给予缬沙坦10mg·kg-1·d-1灌胃治疗,采用免疫组化及RT-PCR检测野生小鼠(WT)和肾上腺髓质素基因敲除小鼠(AMKO)肾脏增殖细胞核抗原(PCNA)、Ⅲ型胶原(ColⅢ)和转化生长因子β1(TGF-β1)的表达。结果野生UUO组小鼠与假手术组相比PCNA阳性细胞数增加,缬沙坦能减少PCNA阳性细胞数。与野生小鼠比较,AMKO假手术组PCNA阳性细胞明显增多,AMKO-UUO组尤为明显,缬沙坦能减少AMKO-UUO组的PCNA阳性细胞数,Ⅲ型胶原和TGF-β1的蛋白表达与mRNA在AM-KO-UUO组明显上调,可被缬沙坦拮抗。结论肾上腺髓质素在UUO介导的肾间质病变的细胞增殖过程中有着重要的作用。     

五种天然药物抑制晶状体上皮细胞增殖效应比较

目的：对五种天然药物姜黄素（curcumine,Cur）、榄香烯（elemene,Ele）、三氧化二砷（arsenitetrioxide,As203）、雷公藤内酯醇（triptolide,Tri）、莪术（rhizomacureumae,Re）抑制重组人碱性成纤维细胞生长因子（recombinant human basic fibroblast growth factor,rhbFGF）诱导的牛晶状体上皮细胞（1ensepithelial cell,LEC）增殖效应进行比较。方法：将rhbFGF诱导体外培养的LEC发生增殖,并用Cur、Ele、As20,、Td、Rc分别与其共同孵育后,用MTT法检测LEC的活性;用流式细胞术（flow cytometer,FCM）检测LEC增殖细胞核抗原（prolif-erating cell nuclear antigen,PcNA）表达。结果：增殖组LEC活性、PCNA蛋白表达显著高于对照组（P〈0．01）;Cur组、Ele组、As,O,组、Tri组、Rc组的LEC活性、PCNA蛋白表达均比增殖组显著降低（P〈0．01）。其中Cur、Ele的作用最强,A鄢O,的作用次之,畅作用较弱,Rc作用最弱（P〈0．01）。Cur和Ele的作用相近（P〉0．05）。结论：五种天然药物Cur、Ele、As,Q、％、Rc均可抑制LEC增殖。Cur和Ele的作用最佳,有希望成为防治后发性白内障的有效药物。     

Genotoxicity and mutagenicity induced by acute crack cocaine exposure in mice

Context: Crack cocaine is an illicit drug derived from cocaine, in which use and abuse have increased around the world, especially in developing countries. Objectives: The aim of this study was to evaluate genomic damage in multiple organs of mice following acute exposure to crack cocaine. For this purpose, single cell gel (comet) assay in peripheral blood, liver, kidney, and brain cells was performed and micronucleus test for bone narrow and liver cells was also made in this setting. Material and methods: A total of 20 C57BL/10 male mice were distributed into four groups, as follows: 0, 4.5, 9, and 18?mg/kg b.w. of crack cocaine dissolved to 1% dimethyl sulfoxide by intraperitoneal (i.p.) route. All animals were sacrificed 24?h after i.p. injection. Results: The results showed that crack cocaine induced DNA damage in peripheral blood, and brain cells for higher doses used as depicted by single cell gel (comet) assay data. Analysis of kidney cells showed no genetic damage for all groups tested. The number of micronucleated cells did not increase after crack cocaine exposure in bone narrow or liver cells. Conclusion: In summary, crack cocaine is a genotoxic agent in peripheral blood, liver, and brain cells but not mutagenic in multiple organs of mice.     

Corneal lesions induced by the systemic administration of capsaicin in neonatal mice and rats

Summary Following a single subeutaneous injection of capsaicin to neonatal mice, a high incidence of corneal lesions with opacity developed after a long latency. The intensity of the lesions progressed for about 1 month in animals which had received a high dose (50 or 100 mg/kg) of capsaicin. Although the intensity gradually decreased thereafter, 50% of animals still exhibited a visible opacity 6 months after treatment. Similar corneal lesions were also produced in neonatal rats which had been injected with capsaicin. It is suggested that the corneal lesions induced by capsaicin may be due to destruction of the trigeminal nerve.     

Reproductive effects of chlorpromazine exposure to female mice: cell proliferation disadvantage revealed by the Chimera Embryo Assay

Administration of chlorpromazine-HCl at 5 to 15 mg/kg bodyweight to pregnant CD-1 mice at 24 h after human chorionic gonadotropin (hCG) (20-23 h after mating) inhibited blastocyst formation and reduced the cell number of embryos recovered at 95 h after hCG. When embryos are recovered at the two- to four-cell stage (48-50 h after hCG) and cultured for an additional 47 h (to 95 h after hCG) or 72 h (to 120 h after hCG), blastocyst formation and embryo cell number were similarly reduced. When the dose range was reduced to 0.5 to 2 mg/kg bodyweight, no significant effect of the drug was observed on blastocyst formation or on embryo cell number. However, when aggregation chimeras were formed between embryos recovered from drug-exposed females and from untreated females, a decrease in cell proliferation rate of the embryo from the drug-exposed female was observed at a dose of 2 mg/kg bodyweight. This result indicates that exposing pregnant mice to chlorpromazine-HCl at doses as low as 2 mg/kg bodyweight can induce a potential for decreased cleavage rate in their pre-implantation embryos that can be revealed by challenging those embryos by direct contact with embryos from nonexposed females. Finally, when four-cell stage embryos recovered from untreated females cultured in the presence of chlorpromazine (0.1-25 mM), blastocyst formation and embryo cell number were significantly reduced in a dose-dependent manner. This last result suggests that in vivo the drug may act directly on the embryo from the pronuclear stage to the early morula stage of development.     

Repeated radon exposure induced lung damage via oxidative stress-mediated mitophagy in human bronchial epithelial cells and mice

This study aimed to investigate the potential molecular mechanism underlying radon-induced lung damage. Our results showed that long-term radon exposure induced mitochondrial damage and redox imbalance in BEAS-2B cells and a time-dependent lung pathological injury in mice. The activation of Nrf-2 and its down-stream antioxidants, and the gene expression of the indicated markers at different stages of autophagy were found to be induced with the increasing of radon exposure time. Changes in the gene expression of PINK-1, Parkin, and p62 induced by radon showed differences in mechanisms of mitophagy activation and profiles of autophagic flux between BEAS-2B cells and mice. Our findings not only demonstrated that long-term radon exposure induced damages to bronchial epithelial cells and the mice lung through increasing oxidative stress, decreasing mitochondrial function and activating mitophagy with different profiles of autophagic flux, but also revealed Nrf-2 as a central regulator of mitochondrial homeostasis and lung damage.     

ACTH-induced behaviors and their modulation by serotonergic agonists differ in neonatal and weanling rat pups

Four-day-old (P4) and 21–22-day-old (P21–22) rat pups received an intracisternal injection of either ACTH1-16_NH2 or saline followed by a subcutaneous (SC) injection of saline, the serotonergic (5HT)_1A agonists 8-OH-DPAT or ipsapirone, the 5HT_1B agonist TFMPP or the 5HT₂ agonist DOI. The ontogeny of ACTH-induced behaviors including grooming, yawn and stretch as well as various serotonin-related behaviors were recorded via time-sampling at 20 s intervals for a test duration of 50 min. ACTH induced slight but significant increases in grooming at P4, along with a significant increase in yawning. At this age the 5HT_1B agonist TFMPP induced substantial increases in grooming, with no effect of the other agonists on this behavior. All of the serotonergic agonists, however, decreased ACTH-induced yawning at P4. At P21–22 ACTH induced more robust grooming than that observed at P4, although different in nature from adult-typical ACTH-induced grooming. This ACTH-induced grooming at P21–22 was attenuated by all of the serotonergic agonists. ACTH-induced yawning at P21–22 was not affected by the serotonergic agonists while ACTH-induced stretching was increased by the 5HT_1B agonist TFMPP at this age. These data provide additional evidence of differential mediation of various ACTH-induced behaviors, and support other reports of ontogenetic alterations in the response to serotonergic manipulations during the neonatal to weanling age period.     

阿霉素诱导小鼠MCF-7乳腺癌细胞凋亡和抑制增殖的体内实验研究

目的:探讨阿霉素对荷瘤鼠MCF7乳腺癌细胞凋亡和增殖的影响。方法:建立小鼠MCF7乳腺癌细胞模型,用TUNEL法和免疫组化法检测阿霉素作用下MCF7乳腺癌细胞的凋亡和PCNA表达的变化。结果:1.25mg·kg-1阿霉素的抑瘤率为43%。MCF7乳腺癌细胞的凋亡指数为1.93%,较荷瘤对照组的1.11%明显升高(P<0.05)。增殖指数为35.75%,较荷瘤对照组的56.38%明显下降(P<0.01)。结论:阿霉素有诱导小鼠MCF7乳腺癌细胞凋亡和抑制其增殖的作用。     

Resveratrol protects the loss of connexin 43 induced by ethanol exposure in neonatal mouse cardiomyocytes

Naunyn-Schmiedeberg's Archives of Pharmacology - Excessive alcohol consumption provides risk to cardiomyopathy with unknown mechanisms. Resveratrol, a plant polyphenol, is widely reported for...