The effects of colcemid on mouse bone marrow.

Following Colcemid administration, mitoses accumulate preferentially in the subendosteal region of the bone marrow of the mouse. This finding suggests that the most rapidly proliferating cells are localized to the subendosteal region, and complements previous radioautographic studies which have demonstrated a corresponding labelling gradient in the marrow. Quantitative estimates of cell cycle time by the stathmokinetic method were precluded by the presence of significant Colcemid induced interphase cell loss. Colcemid also affected cell differentiation in the marrow. Following Colcemid administration there was a fall in mature granulocytes in the marrow, and a concommitant rise in marrow megakaryocytes.     

The genotoxic and cytotoxic effects of nicotine in the mouse bone marrow

The objective of the present study was to investigate the potential of nicotine to induce micronucleated polychromatic erythrocytes (MNPCE) in bone marrow of male and female mice. Cyclophosphamide at 40mg/kg was used as positive control clastogen. Single doses of 4, 8 or 16mg/kg nicotine were given via oral intubation and bone marrow was sampled at 18, 24, 30, 36 and 48h after treatment. Cyclophosphamide yielded the expected positive results. Despite the evident signs of acute toxicity shown by the animals, mainly at the 8 and 16mg/kg doses of nicotine, and the reduction in the % PCE, the results show that the MNPCE frequency in male and female mice was not affected by treatment with any of the selected doses of nicotine, in either of the sampling times 18 or 24h. However, at 30 and 36h after treatment, the MNPCE showed significant increases in both genders after doses of 8 and 16mg/kg. A sex-dependent response was recorded, with males having more MNPCE than females after treatment with 8 or 16mg/kg nicotine and sampling at 30h. However, at 36h more MNPCE were induced in females than in males, suggesting different degrees of dose interaction in the sexes under the conditions of the assay. The response was directly correlated with bone-marrow toxicity, as greater bone-marrow suppression was noted in females than in males when 36h samples were examined. By 48h recovery was observed even though the cytotoxicity was high. These findings suggest that nicotine at high doses and after prolonged time intervals is genotoxic and cytotoxic for mouse bone marrow.     

Analysis of clastogenic effect of Porto Alegre drinking water supplies on mouse bone marrow cells.

Studies were conducted to evaluate the clastogenic activity of drinking water from Porto Alegre and Guaíba (Rio Grande do Sul, Brazil) estuarine waters. Mouse bone marrow was the target organ. C57B1/6 male and female mice received the water samples as their only liquid supply. Bone marrow cells were collected on the 16th day after the beginning of treatment. The analysis of metaphases demonstrated that the water supplies did not increase the structural chromosome aberration frequencies compared to the control groups. Concerning numerical alterations, only one treated female group showed a significant difference (loss of one chromosome) when compared to the control group, but this result is not considered relevant.     

Comparison of the effects of 1,2-dimethylhydrazine and cyclophosphamide on micronucleus incidence in bone marrow and colon

An in vivo micronucleus assay has been developed that utilizes colonic epithelial cells. The genotoxic effects of 1,2-dimethylhydrazine (54-07-3), a colon carcinogen, and of the nitrogen mustard, cyclophosphamide (50-18-0), on the bone-marrow polychromatic erythrocytes and on colonic epithelium from mice were compared using micronucleus induction in each organ as the end point. In the bone marrow, cyclophosphamide was a potent inducer of micronuclei, while 1,2-dimethylhydrazine administration had little effect on the micronucleus incidence. In the colon, 1,2-diemthylhydrazine was an effective inducer of micronuclei. Thus, the colonic micronucleus assay appears to be a potentially useful test for the detection of colon carcinogens.     

Clastogenic effects of acrylamide in mouse bone marrow cells

Acrylamide, known to induce dominant-lethal mutations (Shelby et al., 1986; Smith et al., 1986) and heritable translocations (Shelby et al., 1987) in rodent germ cells, was hitherto a questionable clastogen in rodent bone marrow (Shiraishi, 1978). Therefore, it was tested for chromosomal aberrations in mouse bone marrow cells, spermatogonia and by the micronucleus test. The intraperitoneally injected doses ranged from 50 to 150 mg/kg. In the chromosomal bone marrow test and the micronucleus assay positive results were obtained with acrylamide, and in the latter test the effect increased linearly with dose. Chromosomal aberrations were not induced in differentiating spermatogonia by the acute acrylamide treatment. Cisplatin was used as a positive control and gave the expected positive response in all 3 tests. The present results demonstrate that acrylamide is no exception among clastogens. It breaks chromosomes not only in mammalian germ cells but also in somatic cells.     

Clastogenic effects of cesium chloride on mouse bone marrow cells in vivo

Clastogenic effects of cesium chloride (CsCl) on mouse bone marrow cells in vivo following oral administration were studied after 24 h. The incidence of chromosome aberrations increased linearly with increasing concentrations of the chemical from 1/20th to 1/5th of the LD50. The frequency of cell division was also enhanced by the lower doses but higher doses were mitostatic. This report is the first on the clastogenicity of cesium on animals.     

Impact of sex and age on bone marrow immune responses in a murine model of trauma-hemorrhage.

Although studies have demonstrated that trauma markedly alters the bone marrow immune responses, sex and age are crucial determinants under such conditions and have not been extensively examined. To study this, 21- to 27-day-old (premature), 6- to 8-wk-old (mature), and 20- to 24-mo-old (aged) male and female (proestrus) C3H/HeN mice were sham operated or subjected to trauma (i.e., midline laparotomy) and hemorrhagic shock (30 +/- 5 mmHg for 90 min) followed by fluid resuscitation. Twenty-four hours after resuscitation, bone marrow cells were harvested. Trauma-hemorrhage induced an increased number of the early pluripotent stem cell-associated bone marrow cell subsets (Sca1(+)CD34(-)CD117(+/-)lin(+/-)) in young mice. The CD117(+) proportion of these cell subsets increased in mature proestrus females, but not in males. Aged males displayed significant lower numbers of Sca1(+)CD34(-)CD117(+/-)lin(+/-) cells compared with young male mice. Trauma-hemorrhage also increased development of granulocyte/macrophage progenitor cells (CD11b(+)Gr-1(+)). Proliferative responses to granulocyte macrophage colony-stimulating factor were maintained in mature and aged proestrus females, but decreased in young mice and mature males. Augmented differentiation into monocyte/macrophage lineage in mature and aged proestrus females was observed and associated with the maintained release of TNF-alpha and IL-6. Conversely, increased IL-10 and PGE(2) production was observed in the male trauma-hemorrhage groups. Thus, sex- and age-specific effects in bone marrow differentiation and immune responses after trauma-hemorrhage occur, which are likely to contribute to the sex- and age-related differences in the systemic immune responses under such conditions.     

Efficiency of Coleus aromaticus extract in modifying cyclophosphamide and mitomycin-C induced clastogenicity in mouse bone marrow cells

The anticlastogenic potency of the ethanolic extract of a medicinal plant, C. aromaticus was investigated by taking bone marrow chromosomal aberration assay and micronucleus (MN) test as the test parameters. Swiss albino mice were fed orally with different doses (10,15, 25, 50 and 100 mg/kg body weight) of ethanolic extract for 7 days and on the 7th day, two doses each of anticancer drugs cyclophosphamide (CP; 25 and 50 mg/kg body weight) and mitomycin-C (MMC; 4 and 8 mg/kg body weight) were injected, ip, to different groups of animals. Bone marrow MN preparations were made at 24 and 48 hr time intervals. Coleus extract reduced CP and MMC induced MN and lower doses of the extract were found to be more effective than higher doses. The effective doses of extract in MN test were selected to study the anticlastogenic effects against CP (25 and 50 mg/kg body weight) and MMC (2 and 4 mg/kg body weight) induced chromosomal aberrations. The results indicate the protective effect of C. aromaticus against CP and MMC induced cytogenetic damage.     

Chemoprotective effects of carnosine against genotoxicity induced by cyclophosphamide in mice bone marrow cells

The protective effects of carnosine as a natural dipeptide were investigated in mouse bone marrow cells against genotoxicity induced by cyclophosphamide. Mice were injected with solutions of carnosine at three different doses (10, 50 and 100?mg kg(-1) bw) for five consecutive days. On the fifth day of treatment, mice were injected cyclophosphamide and killed after 24?h. The frequency of micronuclei in polychromatic erythrocytes and the ratio of polychromatic erythrocyte/polychromatic erythrocyte?+?normochromatic erythrocyte [PCE/(PCE?+?NCE)] were evaluated by May-Grunwald/Giemsa staining. Histopathology of bone marrow was examined in mice treated with cyclophosphamide and carnosine. Carnosine significantly reduced micronucleated polychromatic erythrocytes (MnPCEs) induced by cyclophosphamide at all three doses. Carnosine at dose of 100?mg kg(-1) bw reduced MnPCEs 3.76-fold and completely normalized the PCE/(PCE?+?NCE) ratio. Administration of carnosine inhibited bone marrow toxicity induced by cyclophosphamide. It appeared that carnosine with protective activity reduced the oxidative stress and genotoxicity induced by cyclophosphamide in bone marrow cells of mice. Copyright ? 2012 John Wiley & Sons, Ltd.     

Comparison in vivo of the clastogenic properties of busulfan and cyclophosphamide

Cyclophosphamide was given i.p. to male and female mice in order to study the dose--and the time--response relationship for structural chromosome aberrations induced in bone marrow cells. The results were compared to previous observations made with busulfan. After injection of cyclophosphamide the frequency of abnormal cells is maximal after 24 hours and decreases rapidly at longer intervals At comparable doses, the percentage of damaged cells is higher after treatment with busulfan and, due probably to the low solubility of the compound, reaches a maximum only after 48 hours. These results confirm that the most obvious potential drawback of this short term test is the transient nature of such anomalies.     

The humoral nature of the colony-stimulating action of bone marrow cells on stromal colony formation in bone marrow cultures

In 24 hours adherent marrow cell cultures (AMCC) were represented by single stretched fibroblasts. In non-feeder-supplemented AMCC most of the CFU-f remained single fibroblasts or passed through 1-3 cell doublings [correction of dudlings]. The colony stimulating activity of irradiated marrow cells was found to be diffuse across the Millipore filter, which seems to indicate that haemopoietic marrow cells produce a colony stimulating factor which is required for triggering the CFU-f from the Go-period of the cell cycle into cell proliferation.     

Cytogenetic effects of cyclophosphamide on mouse spermatogonia

Summary NMRI mice were treated with single doses of cyclophosphamide (Cytoxan) and spermatogonia were analysed for chromosome aberrations at various time intervals after treatment.The maxima of aberrations were found 24 hrs p.i. Chromatid type aberrations were observed exclusively. About half of the aberrations consisted of chromatid interchanges, 92% of which exchanging short arm fragments close to the centromeric region.The lack of meiotic multivalents in diakinesis-metaphase I after treatment of spermatogonia stem cells with cyclophosphamide in the study of leonard and Linden (1972) is discussed.

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Zusammentassung NMRI-Mäuse erhielten einmalig eine Applikation von Endoxan in verschieden hoher Dosierung. Zu verschiedenen Zeiten nach der Behandlung wurden Tiere getötet und die Spermatogonien analysiert.Das Maximum der induzierten Effekte lag bei 24 Std p.i. Es gelangten ausschließlich Chromatidentypaberrationen zur Beobachtung, die annähernd zur Hälfte aus Chromatidenaustauschen bestanden. Dabei handelte es sich überwiegend (92%) um Segmentaustausche im zentromernahen Bereich.Der fehlende Nachweis von Multivalenten in der Diakinese-Metaphase I nach Behandlung spermatogonialer Stammzellen mit Cyclophosphamid (Leonard u. Linden, 1972) wird diskutiert.

     

Comparative investigation of cyclophosphamide action on bone marrow cells of the Armenian hamster and 4 other species of rodents.

We studied the clastogenic action of cyclophosphamide (CP) on bone marrow cells of the Armenian hamster (AH), Cricetulus migratorius. CP induced a dose-dependent linear increase in aberrant cells. The maximal cytogenetic action was observed 12 h after CP treatment. Male and female AHs were similarly sensitive to the clastogenic action of CP. We compared CP clastogenicity at a dose of 25 mg/kg on bone marrow cells of AHs, mice, rats, guinea pigs and Chinese hamsters 24 h after treatment. We observed that this dose of CP induced only 2.8% aberrant cells in bone marrow of AHs, but 42.8%, 32.2%, 25% and 14.6% aberrant cells in bone marrow of guinea pigs, rats, mice and Chinese hamsters respectively. AHs are much more resistant to the metaphase-arresting action of colchicine than other species of rodents (e.g., the colchicine dose for AHs is 100-fold more than for rats). Thus AHs are the most resistant of all rodent species studied to the clastogenic action of CP.     

Kinetics of rebounding of lymphoid and myeloid cells in mouse peripheral blood, spleen and bone marrow after treatment with cyclophosphamide

Recently, we showed that post cyclophosphamide (CTX) microenvironment benefits the function of transferred T cells. Analysis of the kinetics of cellular recovery after CTX treatment showed that a single 4 mg/mouse CTX treatment decreased the absolute number of leukocytes in the peripheral blood (PBL) at days 3-15, and in the spleen and bone marrow (BM) at days 3-6. The absolute numbers of CD11c(+)CD11b(-) and CD11c(+)CD11b(+) dendritic cells (DCs), CD11b(+) and Ly6G(+) myeloid cells, T and B cells, CD4(+)CD25(+) T regulatory (T(reg)) cells, and NK1.1(+) cells also decreased. The cell numbers returned to control levels during the recovery phase. The absolute numbers of B cells remained low for 3 weeks. The numbers of DCs increased in PBL and spleen at day 9 but returned to control levels at day 15. These data indicate that CTX alters the cellular microenvironment in kinetics that might be precisely targeted to benefit the host.